View Full Version : Who does BCM source their barrels from?
D.S. Brown
02-11-22, 11:18
Mods please disregard question and DELETE thread.
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It’s a shame this question has never been asked on the internet. Ever.
It’s a shame this question has never been asked on the internet. Ever.
There is a lake in the North of England known only to Merlin and Paul Buffoni, and in this lake there is a Lady whom gifts them with rare blades and forged barrels... or so the ledged goes.
FN, to answer that question, they might have someone doing their 416r or their "Mid-Weight" barrels, but I don't know who that would be.
The thread title ending in a preposition is too troubling for me to think about barrels.
The thread title ending in a preposition is too troubling for me to think about barrels.
"This is the type of arrant pedantry up with which I will not put." Winston Churchill
:laugh:
Cheers, Steve
:laugh: I need to go shoot.
That’s probably the best kept secret in the gun industry.
Mossberg, LWRCI ?? These days nothing would surprise me.
SOLGW isn't afraid to reveal who makes their barrels.
Mossberg, LWRCI ?? These days nothing would surprise me.
No way! We've shot too many good Bravos to be from either of those dumps.
I will guess it is Rosco.
Hammer_Man
02-11-22, 23:12
Well it’s probably not Remington.
MikhailBarracuda91
02-12-22, 00:49
I will guess it is Rosco.I've actually heard that it is Rosco for their button rifled barrels. But as far as the CHF ones, probably FN.
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Have read that Criterion supplied the SS barrels, no idea if that is still true.
Why not try and ask the head honcho @ BCM? Worse thing he will tell the OP to %$#k off.
Mark
ThirdWatcher
02-12-22, 11:20
My BCM4 middy is the most accurate AR I own.
Have read that Criterion supplied the SS barrels, no idea if that is still true.
Why not try and ask the head honcho @ BCM? Worse thing he will tell the OP to %$#k off.
Mark
He won’t even tell you that.
pointblank4445
02-12-22, 14:47
It’s a shame this question has never been asked on the internet. Ever.
But has it ever "REALLY" been answered?
"Those that know don't say; those that say don't really know..."
It probably matters little. They have a stellar reputation regardless of source.
pointblank4445
02-12-22, 16:02
It probably matters little. They have a stellar reputation regardless of source.
Ultimately, yeah.
But as I'm sure you know (if one spends any time around HK and HK people) that getting "into the weeds" can be enlightening and empowering up until it becomes a complete F***ing dragon chase of obsession with specs and minutiae.
pointblank4445
02-12-22, 16:02
It probably matters little. They have a stellar reputation regardless of source.
Ultimately, yeah.
But as I'm sure you know (if one spends any time around HK and HK people) that getting "into the weeds" can be enlightening and empowering up until it becomes a complete F***ing dragon chase of obsession with specs and minutiae.
To those that it does matter...SOLGW is very transparent about who makes their barrels, BCG's, receivers, rails, triggers, pins, & springs.
They will tell you who and why.
Ultimately, yeah.
But as I'm sure you know (if one spends any time around HK and HK people) that getting "into the weeds" can be enlightening and empowering up until it becomes a complete F***ing dragon chase of obsession with specs and minutiae.
I'm an HK owner, but I can't go down into the netherworld with precision measurements obsessions...lol
the AR-15 Junkie
02-12-22, 19:04
SOLGW isn't afraid to reveal who makes their barrels.
YEAH, Ballistic Advantage, high end of low tier at best.
Ultimately, yeah.
But as I'm sure you know (if one spends any time around HK and HK people) that getting "into the weeds" can be enlightening and empowering up until it becomes a complete F***ing dragon chase of obsession with specs and minutiae.
HK won’t even disclose the metallurgy of the steel they obtain as a poorly kept secret from Aubert and Duvall.
Then again, I saw just today HKPro is now infested with folks obsessed with making “John Wick” kits, including the gold coins.
Sheesh…………That’s not me.
- Hold on a sec while I pick Axe my basement floor.-
YEAH, Ballistic Advantage, high end of low tier at best.
Yeah ok Intellectual Property Colt guy. - Whatever-
YEAH, Ballistic Advantage, high end of low tier at best.
I own both and I would take Ballistic Advantage over BCM.
pointblank4445
02-13-22, 11:09
HK won’t even disclose the metallurgy of the steel they obtain as a poorly kept secret from Aubert and Duvall.
.-
It’s not as secret as some believe.
One thing that is no secret is how far HKPRO has fallen...but then they all do.
To those that it does matter...SOLGW is very transparent about who makes their barrels, BCG's, receivers, rails, triggers, pins, & springs.
They will tell you who and why.
They are also much, much, smaller than BCM. If you don't understand why I point it out, it is because sourcing barrels is much like sourcing anything else. Things are held to a standard, as long as that standard is met everything is great.
To those that it does matter...SOLGW is very transparent about who makes their barrels, BCG's, receivers, rails, triggers, pins, & springs.
They will tell you who and why.
They are also much, much, smaller than BCM. If you don't understand why I point it out, it is because sourcing barrels is much like sourcing anything else. Things are held to a standard, as long as that standard is met everything is great.
They are also much, much, smaller than BCM. If you don't understand why I point it out, it is because sourcing barrels is much like sourcing anything else. Things are held to a standard, as long as that standard is met everything is great.
I remember reading or seeing an interview with BCM when they were getting into their own rifles and them talking about their rejection rate for barrels being very high in comparison to the industry average.
pointblank4445
02-13-22, 17:58
I remember that too. Thought it was LAV. Didn't find it but they reference it again here:
https://www.youtube.com/watch?v=BaFOZAwspYI
They are also much, much, smaller than BCM. If you don't understand why I point it out, it is because sourcing barrels is much like sourcing anything else. Things are held to a standard, as long as that standard is met everything is great.
This^^^
Why does this keep coming up? I don't know, but I would be very surprised if they have only one source. I know I would have more than one source that I shopped if BCM was my company.
Contract specs, acceptable tolerances, QA/QC inspection protocols, and conditions of acceptance matter WAY more than "who makes it".
I remember reading or seeing an interview with BCM when they were getting into their own rifles and them talking about their rejection rate for barrels being very high in comparison to the industry average.
This^^^
Why does this keep coming up? I don't know, but I would be very surprised if they have only one source. I know I would have more than one source that I shopped if BCM was my company.
Contract specs, acceptable tolerances, QA/QC inspection protocols, and conditions of acceptance matter WAY more than "who makes it".
I hesitate to raise this issue, but with BCM claiming that they reject more than their share of barrels, I found it curious that they seem to have a mediocre reputation for accuracy. Some people have had great luck with their barrels, whist seemingly many others have complained in regards to sub standard accuracy. It just strikes me as odd that a company who brags about their high standards for barrels has developed a reputation for sub par accuracy.
One might argue that some of those accuracy complaints were due to the incompetence of the shooter. Fair enough. But then why wouldn't other similar tier rifles have a similar frequency of complaints?
I do have a couple 16" BCMs, a lightweight barrel FSB midlength, and a midlength RECCE ELW, both BFH. Have never shot them with match ammo and a sufficient scope to test their true accuracy potential, but nonetheless compared to others I've tested equally casually, they both seem a bit subpar. Based on my very limited experience and the complaints I've read, I wouldn't say there's anything special about their barrels. Even less so compared to someone like DD or Colt, who both have very good reputations for accuracy.
Just my 2 cents.
Mysteryman
02-13-22, 22:20
I hesitate to raise this issue, but with BCM claiming that they reject more than their share of barrels, I found it curious that they seem to have a mediocre reputation for accuracy. Some people have had great luck with their barrels, whist seemingly many others have complained in regards to sub standard accuracy. It just strikes me as odd that a company who brags about their high standards for barrels has developed a reputation for sub par accuracy.
One might argue that some of those accuracy complaints were due to the incompetence of the shooter. Fair enough. But then why wouldn't other similar tier rifles have a similar frequency of complaints?
I do have a couple 16" BCMs, a lightweight barrel FSB midlength, and a midlength RECCE ELW, both BFH. Have never shot them with match ammo and a sufficient scope to test their true accuracy potential, but nonetheless compared to others I've tested equally casually, they both seem a bit subpar. Based on my very limited experience and the complaints I've read, I wouldn't say there's anything special about their barrels. Even less so compared to someone like DD or Colt, who both have very good reputations for accuracy.
Just my 2 cents.
BCM isn't selling rifles or barrels with the precision shooter in mind. They build milspec rifles and barrels that offer acceptable accuracy for the role they are intended for. The rampant obsession over accuracy is misguided.
Own BCMs, have some very good BCM barrels, recommend BCM, etc etc.
BCM isn't selling rifles or barrels with the precision shooter in mind. They build milspec rifles and barrels that offer acceptable accuracy for the role they are intended for. The rampant obsession over accuracy is misguided.
You're not wrong. But, the most precision within a set of specs or parameters (like a 0-300 typical fighting carbine) isn't a bad thing. Options for capabilities. Anymore, I'd like any new AR I get to ship with 3-5 uppers to shoot and I'll keep the best one.
fedupflyer
02-13-22, 23:21
I do have a couple 16" BCMs, a lightweight barrel FSB midlength, and a midlength RECCE ELW, both BFH. Have never shot them with match ammo and a sufficient scope to test their true accuracy potential, but nonetheless compared to others I've tested equally casually, they both seem a bit subpar.
By your own admission you have disqualified yourself.
I don’t believe BCM has really marketed themselves based purely on accuracy.
My test result with a fixed x10 scope, match grade ammo, 1/7 barrel resulted in MOA to sub MOA accuracy.
By your own admission you have disqualified yourself.
I don’t believe BCM has really marketed themselves based purely on accuracy.
My test result with a fixed x10 scope, match grade ammo, 1/7 barrel resulted in MOA to sub MOA accuracy.
I wasn't complaining about BCMs' accuracy, just saying it wasn't particularly good in comparison to my other rifles, tested similarly. All were shot with basic M193, M855, and Hornady TAP, using front and rear bags and Geissele triggers. The BCMs seem to consistently shoot the largest groups. Like I said earlier, not a true test, but enough in my mind to confirm what a lot of other people have been saying about their barrels not being especially accurate.
Combat accurate, for sure, but considering BCM's brag about rejecting more barrels than anyone in the industry, it seems odd. No?
ViniVidivici
02-14-22, 00:14
Their lower tier stuff comes from Bear Creek Arsenal, their higher end comes from Larue.
fedupflyer
02-14-22, 00:57
I wasn't complaining about BCMs' accuracy, just saying it wasn't particularly good in comparison to my other rifles, tested similarly. All were shot with basic M193, M855, and Hornady TAP, using front and rear bags and Geissele triggers. The BCMs seem to consistently shoot the largest groups. Like I said earlier, not a true test, but enough in my mind to confirm what a lot of other people have been saying about their barrels not being especially accurate.
Combat accurate, for sure, but considering BCM's brag about rejecting more barrels than anyone in the industry, it seems odd. No?
What optic were using during these tests?
Mysteryman
02-14-22, 01:49
Own BCMs, have some very good BCM barrels, recommend BCM, etc etc.
You're not wrong. But, the most precision within a set of specs or parameters (like a 0-300 typical fighting carbine) isn't a bad thing. Options for capabilities. Anymore, I'd like any new AR I get to ship with 3-5 uppers to shoot and I'll keep the best one.
That would be nice. More performance isn't a bad thing, but some make it out like it's a necessity when it isn't. At least not in most cases.
I wasn't complaining about BCMs' accuracy, just saying it wasn't particularly good in comparison to my other rifles, tested similarly. All were shot with basic M193, M855, and Hornady TAP, using front and rear bags and Geissele triggers. The BCMs seem to consistently shoot the largest groups. Like I said earlier, not a true test, but enough in my mind to confirm what a lot of other people have been saying about their barrels not being especially accurate.
Combat accurate, for sure, but considering BCM's brag about rejecting more barrels than anyone in the industry, it seems odd. No?
Nothing odd about rejecting barrels. Accuracy isn't the only parameter used to determine if the barrel is acceptable or not. Again, the rampant focus on accuracy is misguided and not the most important aspect, nor is it always a factor.
Pauls comments about rejecting barrels in the early days were because they sourced from green mountain. That being said GM makes some solid stuff now.
As for sources, I can only guess except im positive the chf are FN. The SS and button could be from a dozen places.
I have a 2009ish and a 2016ish...I can't remember when I got the uppers. They are the standard BCM middy with an FSB.
Both shoot an acceptable enough grouping at 50 yds with a red dot making a decent group doing head shots..with XM193 and green tip Lake City bulk ammo
sidewaysil80
02-14-22, 06:04
BCM isn't selling rifles or barrels with the precision shooter in mind. They build milspec rifles and barrels that offer acceptable accuracy for the role they are intended for. The rampant obsession over accuracy is misguided.
My own issues and most of the accuracy complaints I’ve seen were regarding their SS410 precision barrels. I don’t think it’s misguided to expect above “mil-spec” rack accuracy out of a barrel that is marketed and priced as a precision rifle/marksman rifle.
Their lower tier stuff comes from Bear Creek Arsenal, their higher end comes from Larue.
Yikes, BCA is pretty much hot garbage, I bet the reject rate on those is quite high and QA basically is a necessity.
I wonder how much of the BCM accuracy is due to the thermal fitment of the upper receivers?
My own issues and most of the accuracy complaints I’ve seen were regarding their SS410 precision barrels. I don’t think it’s misguided to expect above “mil-spec” rack accuracy out of a barrel that is marketed and priced as a precision rifle/marksman rifle.
I have the opposite opinion. I have found their chrome lined barrels to be overgassed, and tight chambered, but I have owned 4 of their SS410 uppers and they were all laser accurate.
I build and work on a decent sample of ARs and have had enough problems with BCM that I don’t recommend any of their complete uppers or lowers anymore.
I regularly use their upper and lower parts kits, receiver extension kits, and PNT triggers though.
Yikes, BCA is pretty much hot garbage, I bet the reject rate on those is quite high and QA basically is a necessity.
I wonder how much of the BCM accuracy is due to the thermal fitment of the upper receivers?
When I read Vinividivici’s post, my sarcasm meter maxed out.
***snip*** tight chambered, ***snip***.
Would you mind elaborating on that?
When I read Vinividivici’s post, my sarcasm meter maxed out.
Figures, that went right over my head.
Nothing odd about rejecting barrels. Accuracy isn't the only parameter used to determine if the barrel is acceptable or not. Again, the rampant focus on accuracy is misguided and not the most important aspect, nor is it always a factor.
That makes a good sound bite but it doesn’t really say anything.
Reliability is the most important factor but many companies make reliable “mil-spec” barrels or complete uppers. if you have two barrels available that meet the same specs, why would you ever choose the less accurate one?
Once you have reliability, accuracy is always a factor to people that want to hit their target.
When I read Vinividivici’s post, my sarcasm meter maxed out.
Would you mind elaborating on that?
Tight or short chamber causing excessive pressure signs, pierced primers, fail to extract, ripped head off case.
When I read Vinividivici’s post, my sarcasm meter maxed out.
Would you mind elaborating on that?
Tight or short chamber causing excessive pressure signs, pierced primers, fail to extract, ripped head off case.
Figures, that went right over my head. happens to me all the time.
Tight or short chamber causing excessive pressure signs, pierced primers, fail to extract, ripped head off case.
Thanks. Have you gauged any or made a casting?
happens to me all the time.
Thanks. Have you gauged any or made a casting?
Nope. Just suspected that the chamber dimensions were off and confirmed with go/no go gages.
Their lower tier stuff comes from Bear Creek Arsenal, their higher end comes from Larue.
The sad part is there are people who believed you.
I hesitate to raise this issue, but with BCM claiming that they reject more than their share of barrels, I found it curious that they seem to have a mediocre reputation for accuracy. Some people have had great luck with their barrels, whist seemingly many others have complained in regards to sub standard accuracy. It just strikes me as odd that a company who brags about their high standards for barrels has developed a reputation for sub par accuracy.
One might argue that some of those accuracy complaints were due to the incompetence of the shooter. Fair enough. But then why wouldn't other similar tier rifles have a similar frequency of complaints?
I do have a couple 16" BCMs, a lightweight barrel FSB midlength, and a midlength RECCE ELW, both BFH. Have never shot them with match ammo and a sufficient scope to test their true accuracy potential, but nonetheless compared to others I've tested equally casually, they both seem a bit subpar. Based on my very limited experience and the complaints I've read, I wouldn't say there's anything special about their barrels. Even less so compared to someone like DD or Colt, who both have very good reputations for accuracy.
Just my 2 cents.
I find it odd to given who they source from but I can say for me, all 3 were not great shooters. They went bang everytime and had zero issues but accuracy was mediocre at best. I will say that they were my least accurate production rifles.
I find it odd to given who they source from but I can say for me, all 3 were not great shooters. They went bang everytime and had zero issues but accuracy was mediocre at best. I will say that they were my least accurate production rifles.
Same here. In fact, they're my least accurate rifles. Period. Still wouldn't feel under gunned with one though. Just won't be buying any more.
ETA: This has got me thinking of seeing what I can do to accurize them a bit. Wondering if truing the receiver face, and maybe shimming the barrel nut so I can get the gas tube lined up on the lower end of the torque range would help. I know BCM is known for torqueing the living crap out of everything. Any ideas, anyone?
ForteeFiveSeventee
02-15-22, 18:56
I have a BCM 16" enhanced light-weight fluted pencil barrel rifle and it shoots just over an inch 5-shot groups at 100 yards with IMI 77gr SMKs. I have zero experience with any other BCM rifles but this is my defensive gun and I trust it completely.
https://i.ibb.co/4Z5FHVT/IMG-1324.jpg
Same here. In fact, they're my least accurate rifles. Period. Still wouldn't feel under gunned with one though. Just won't be buying any more.
ETA: This has got me thinking of seeing what I can do to accurize them a bit. Wondering if truing the receiver face, and maybe shimming the barrel nut so I can get the gas tube lined up on the lower end of the torque range would help. I know BCM is known for torqueing the living crap out of everything. Any ideas, anyone?
PTG’s receiver face truing thingy doesn’t fit in the bore of the BCM Mk2 receiver that I checked. Supposedly the same bore as the regular uppers they sell. I’ve heard that other brands will fit, but don’t remember which.
PTG’s receiver face truing thingy doesn’t fit in the bore of the BCM Mk2 receiver that I checked. Supposedly the same bore as the regular uppers they sell. I’ve heard that other brands will fit, but don’t remember which.Thanks for saving me some money... I wonder if I could get the same effect with a sheet of 600 grit on a trued flat surface and just doing a bunch of figure 8s on it with the face of the receiver.
ViniVidivici
02-16-22, 00:16
A glass plate w/ sandpaper, very flat, but I dont see how you'd keep the upper perfectly perpendicular.
A glass plate w/ sandpaper, very flat, but I dont see how you'd keep the upper perfectly perpendicular.I do have one of those that I use to resurface my knife sharpening stones. I tend to think that the issue isn't the flatness of the receiver face, but rather the tightness of the barrel nut.
Same here. In fact, they're my least accurate rifles. Period. Still wouldn't feel under gunned with one though. Just won't be buying any more.
ETA: This has got me thinking of seeing what I can do to accurize them a bit. Wondering if truing the receiver face, and maybe shimming the barrel nut so I can get the gas tube lined up on the lower end of the torque range would help. I know BCM is known for torqueing the living crap out of everything. Any ideas, anyone?
agree
I like to build my sticks but I still buy kac, lmt and I've recently become quite fond of centurion arms products. I have one of their cm4 rifles and the fker has been reliable and accurate. I'm not sure who sources their barrels but the accuracy is on par with my noveske afghan and colt socoms (I use these two as the baseline for rack grade accuracy as these are well known for accuracy and I can personally attest to it).
Same here. In fact, they're my least accurate rifles. Period. Still wouldn't feel under gunned with one though. Just won't be buying any more.
ETA: This has got me thinking of seeing what I can do to accurize them a bit. Wondering if truing the receiver face, and maybe shimming the barrel nut so I can get the gas tube lined up on the lower end of the torque range would help. I know BCM is known for torqueing the living crap out of everything. Any ideas, anyone?
I just replace their barrels with DD barrels and that seems to solve the problem.
I have never tested BCM accuracy, but given I have hit pretty much everything I have aimed at to 500 yards (700 with the Mk12 barrel) for me and what I need they have been 100% accurate. "Precision" and "mass produced AR" have never screamed 'one hole at 'n' yards' to me. If I wanted a 'real' Mk12 or SAM-R I would have a Douglass, Lilja, etc. barreled upper.
BCM’s MK12 ain’t no slouch. I would put them up there with most any stainless barrel. I’ve had two of them and a couple of the KD4 uppers. All of them were badass.
ETA: This has got me thinking of seeing what I can do to accurize them a bit. Wondering if truing the receiver face, and maybe shimming the barrel nut so I can get the gas tube lined up on the lower end of the torque range would help. I know BCM is known for torqueing the living crap out of everything. Any ideas, anyone?
Colt is the same way... as far as tight assembly across the whole gun. I simply don't shoot a semi accurately enough to realize any gain from receiver truing. I have the tool, and have done it to a few guns, but I'm too squirrely to shoot a 2 stage trigger with a bolt reciprocating to a level of great accuracy.
I have never tested BCM accuracy, but given I have hit pretty much everything I have aimed at to 500 yards (700 with the Mk12 barrel) for me and what I need they have been 100% accurate.
^^^This
BCM’s MK12 ain’t no slouch. I would put them up there with most any stainless barrel. I’ve had two of them and a couple of the KD4 uppers. All of them were badass.
I have not shot it to any volume and certainly not to the degree of which I shot the Mk12 and SAM-R. But I definitely don't mind stretching it's legs and giving it a go. I have become a Douglas and Lilja snob; but then, I never had to pay for those guns either lol.
ViniVidivici
02-16-22, 09:45
I do have one of those that I use to resurface my knife sharpening stones. I tend to think that the issue isn't the flatness of the receiver face, but rather the tightness of the barrel nut.
So is the thinking that, having the barrel nut tightened on the low end (basically, less tight) is conducive to greater accuracy, all things being equal?
To say that a super-tight barrel nut can make the gun less accurate?
So is the thinking that, having the barrel nut tightened on the low end (basically, less tight) is conducive to greater accuracy, all things being equal?
To say that a super-tight barrel nut can make the gun less accurate?
I think there's a lot of dogma in these assumptions. To paraphrase Sinister (here) 99% of shooters will never realize the difference in Receiver Truing, Barrel nut torque, and Flash hider torque.
You really have to have every little thing, including ammo, super buttoned up to sweat these type of variables. (that's just my opinion.)
So is the thinking that, having the barrel nut tightened on the low end (basically, less tight) is conducive to greater accuracy, all things being equal?
To say that a super-tight barrel nut can make the gun less accurate?
On a quality reciver it has more to do with flaws in the anodization. You are just trying to make the surface perfectly flat in relation to the receiver extension. If you ever had an upper where sighting in was all the way to one side, this is generally the issue. I had have an LMT that has this issue but as soon as I trued up the face it was dead center. Best way to do it is to put it in a lathe.
If it is a precision gun and you spend good money on a barrel I think it's a no brainer. It follows the same thought process as bedding the barrel (although BCM has eliminated the bedding issue with the thermal fit). No reason to do any of this if it's not a precision AR. Good write up if your interested - https://www.bexararms.net/blog/receiver-face-squaring/.
So is the thinking that, having the barrel nut tightened on the low end (basically, less tight) is conducive to greater accuracy, all things being equal?
To say that a super-tight barrel nut can make the gun less accurate?
I've read both that having the nut torqued to the low end and to the high end can improve accuracy. I honestly don't know, but as I know that BCM tends to torque the crap out of everything, I wondered if that may have something to do with it. Was hoping someone with some direct experience would chime in and give me some clarity on it before I dive in.
Was hoping someone with some direct experience would chime in and give me some clarity on it before I dive in.
Clarify what you're looking for. Are you asking if someone reduced the torque value on a BCM nut?
There have been so many of these threads here and on other sites discussing the accuracy of BCM. There are many youtube videos. The bottom line, to me, is that most BCM barrels are plenty accurate if the shooter does a competent job. I think many folks, myself included, make more of a comment on their own shooting abilities and/or lack there of when making accuracy claims. Mrguns and gear has vid of shooting with different ammo and gets 1.25-1.7. Molon gets MOA. Frankly, I don't have the patience nor skill to shoot tiny groups. I do have friends who are into that. I hand them my rifles, after I sight them in to see what the accuracy potential is with my reloads and using whatever sighting system is on that upper. They have all the right gear etc and techniques. My throwing the gun over a bag and my ability demonstrates a 3 inch group and they shoot 1.3.
Hence, I have come to the conclusion that my BCM's are accurate enough. I thought my Sionics were a bit more accurate and they may shoot a bit tighter, as demonstrated by my friends--who are capable.However, the difference is minute and not something that will make a difference for my shooting.
Just some random thoughts.
YMMV, Cheers, Steve
Great point. BCMs are fighting guns built to high standards. Their "target" customer isn't match shooters... it's "Gunfighters".
There have been so many of these threads here and on other sites discussing the accuracy of BCM. There are many youtube videos. The bottom line, to me, is that most BCM barrels are plenty accurate if the shooter does a competent job. I think many folks, myself included, make more of a comment on their own shooting abilities and/or lack there of when making accuracy claims. Mrguns and gear has vid of shooting with different ammo and gets 1.25-1.7. Molon gets MOA. Frankly, I don't have the patience nor skill to shoot tiny groups. I do have friends who are into that. I hand them my rifles, after I sight them in to see what the accuracy potential is with my reloads and using whatever sighting system is on that upper. They have all the right gear etc and techniques. My throwing the gun over a bag and my ability demonstrates a 3 inch group and they shoot 1.3.
Hence, I have come to the conclusion that my BCM's are accurate enough. I thought my Sionics were a bit more accurate and they may shoot a bit tighter, as demonstrated by my friends--who are capable.However, the difference is minute and not something that will make a difference for my shooting.
Just some random thoughts.
YMMV, Cheers, Steve
key here is 'rack grade rifles'. no doubt many are within acceptable specs for accuracy but you can most certainly differentiate between a 3-4 moa and 1-2 rig. I do agree, way too many people think you are getting clover leafs with 55gr 193 out of these rifles and that is just not realistic. expectations vs realism; same old battle lol
My BCM uppers/barrels have generally been capable of pretty decent accuracy. However it should also be pointed out that every BCM I have is a non-free floated with a fixed FSB, so not precision rigs at all.
One odd thing I have noticed is that I have a complete BCM 20” “A4” style upper that seems like it has a POI shift issue. The group sizes are fine but it appears as though the groups start walking progressively farther to the left after only like 15-20 rounds or so, fired at a fairly slow “shooting for groups” pace, same ammo each time. I haven’t had the time or the cooperative weather to really dig into this to see what’s up, but my initial impressions are that something weird is going on with the barrel as it gets warm. I haven’t contacted BCM yet because I want to really be sure something is actually going on first and it isn’t just a case of me having a series of really off range trips or something, but I haven’t encountered this type of consistent, repeated POI shift with any of my other guns.
Clarify what you're looking for. Are you asking if someone reduced the torque value on a BCM nut?
I'm asking if people have determined if being on the lower end of the barrel nut torque spec improves accuracy. I've read that it does, but I've also read the opposite. Was just looking to hear if anyone had had any experiences one way or the other.
ViniVidivici
02-16-22, 14:09
I too am still curious about this.
I researched when assembling uppers for the firsttime, and it was inconclusive, 6 one half dozen the other, so still wanting to hear from those "in the know".
I'm asking if people have determined if being on the lower end of the barrel nut torque spec improves accuracy. I've read that it does, but I've also read the opposite. Was just looking to hear if anyone had had any experiences one way or the other.
I suspect nut torque has a relationship to barrel harmonics, and thus reverb of barrel.
Likely rare circumstances where lower torque allows for some additional damping to occur?
Accuracy & Precision will be closely tied to barrel harmonics, which of course has "100" different variables that define those harmonics.
The barrel certainly won't bend into yield, but it could possibly not return back to "zero", thus throwing off Accuracy/Precision at distance. Noticeable in moa over reach of a round? Maybe, maybe not.
When I run a search for who makes BCM barrels, seems like the common reply is "FN". Although in same results the replies seems to suggest some BCM barrels are not FN.
The guns I have seen use the lower end of the recommended barrel nut torque per a given rail. So a BCM MCMR recommended torque value is 40-50 ft-lbs, so you would go 40. That being said, rails like a URX 4 are set, the rail is the barrel nut and you are timing the rail with shims for alignment. Other rails like geissele only give a fixed value like 40 ft-lbs.
In my experience the higher end rails use a much lower torque value than what is spec - 30 to 80 ft-lbs. That being said, the GI stock barrel nut has not been torqued, only indexed to line up with the gas tube and not to exceed 80 ft-lbs. We have come a long way. Based of those two data points I would assume lower is better.
I used to be good friends with a master gunsmith that has built some insanely accurate ARs. If he had a client that was building for accuracy he would true the face, bed the barrel, go low torque on the barrel nut, and very low on the mussel device and just use rockset to hold it in place. He used to say barrels are tuning forks and you dont want to put undue pressure when it is not needed as you will mess up the harmonics.
That being said, rails like a URX 4 are set, the rail is the barrel nut and you are timing the rail with shims for alignment.
Each KAC URX4 that I have purchased came with two separate installation instructions. One says 60-70ft/lbs (+\-5) the other says 60-140 ft-lbs.
Each KAC URX4 that I have purchased came with two separate installation instructions. One says 60-70ft/lbs (+\-5) the other says 60-140 ft-lbs.
My point being the value is totally dependant on the upper and how the rail indexes to the upper receiver and how different rail types and manufactures deal with the torque values in different ways. In my experience with the URX 4 getting to 11:00 is far more important than the torque spec. I think Knights is giving you outs if you can't get timed correctly.
In my experience the higher end rails use a much lower torque value than what is spec
In some cases (not all), a lower torque recommendation is because the nuts in some of the aftermarket rails are not as strong as a Colt standard barrel nut. I'm personally not comfy with torque value at either extreme. The only time I'll use a torque wrench is when it an install for a more "fragile" nut/rail system.
ForteeFiveSeventee
02-16-22, 18:18
I think it has more to do with how well the rifling is cut (especially at the muzzle end), how properly (tight) chambered the barrel is, and how properly seated the receiver extension is than how flat the upper receiver is or how tightly the barrel is torqued down. I also think the barrel nut to upper receiver "seasoning' is important as is using a quality assembly grease. I've pulled barrels and reinstalled them and not experienced any detriment to accuracy. I've also replaced barrels in Savage bolt action receivers with similar results. I use aeroshell, a quality, calibrated torque wrench and a Midwest Industries receiver supported action rod.
I think it has more to do with how well the rifling is cut (especially at the muzzle end)
I don't think any of the barrels related to this discussion are cut rifling... I'd doubt even the SS barrels. (I could be wrong)
I don't think any of the barrels related to this discussion are cut rifling... I'd doubt even the SS barrels. (I could be wrong)BCM used hammer forged and standard rifled barrels, and I'm pretty sure all their SS barrels are cut, not forged.
Regarding my question about whether barrel nut torque affects accuracy. The consensus seems to be that it does not, as long as it is within spec. Rifles have been tested across the torque range, and there's no correlation between accuracy and barrel nut torque in ARs.
fedupflyer
02-16-22, 20:36
Regarding my question about whether barrel nut torque affects accuracy. The consensus seems to be that it does not, as long as it is within spec. Rifles have been tested across the torque range, and there's no correlation between accuracy and barrel nut torque in ARs.
If you go read Glenn Zediker book(s) on building ARs, he advocates torque on the lower end.
IIRC it was somewhere between 35-40 ft/lbs.
Zidiker was an NRA High Power champ and was very knowledgeable.
According to him a high torque and accuracy would suffer. Even more so with an over torqued muzzle device.
I bought a ALG handguard a few yrs back and it did not have a torque value but you used a certain length pipe as leverage and turned the barrel nut to match a visual range on a spacer/shim.
It felt like it was around 40 ft/lbs
Mysteryman
02-16-22, 22:09
My own issues and most of the accuracy complaints I’ve seen were regarding their SS410 precision barrels. I don’t think it’s misguided to expect above “mil-spec” rack accuracy out of a barrel that is marketed and priced as a precision rifle/marksman rifle.
That's fair..
That makes a good sound bite but it doesn’t really say anything.
Reliability is the most important factor but many companies make reliable “mil-spec” barrels or complete uppers. if you have two barrels available that meet the same specs, why would you ever choose the less accurate one?
Once you have reliability, accuracy is always a factor to people that want to hit their target.
Again, accuracy isn't always a factor. If you feed it 55/62gr bulk ammo you're all but wasting your time worrying about accuracy. Add in an RDS, unsupported positions and a specific purpose/role like HD/PD and mechanical accuracy is far from a primary concern. Two barrels that both meet spec, both meet spec. You will never know how well they perform until you shoot them.
Regarding my question about whether barrel nut torque affects accuracy. The consensus seems to be that it does not, as long as it is within spec. Rifles have been tested across the torque range, and there's no correlation between accuracy and barrel nut torque in ARs.
If you already have the shims - Why not just do your OWN experiments on YOUR rifle with respect to the torque and see if you notice any changes?
Having read all of your posts in this thread - I think you ought to just go for it and go all in with all of your ideas.
ETA: This has got me thinking of seeing what I can do to accurize them a bit. Wondering if truing the receiver face, and maybe shimming the barrel nut so I can get the gas tube lined up on the lower end of the torque range would help. I know BCM is known for torqueing the living crap out of everything. Any ideas, anyone?
PTG’s receiver face truing thingy doesn’t fit in the bore of the BCM Mk2 receiver that I checked. Supposedly the same bore as the regular uppers they sell. I’ve heard that other brands will fit, but don’t remember which.
Thanks for saving me some money... I wonder if I could get the same effect with a sheet of 600 grit on a trued flat surface and just doing a bunch of figure 8s on it with the face of the receiver.
A few comments about your previous posts:
Please don't try to true your receiver face like you mentioned. You are going to end up with a flat surface that is cocked to one side or the other and not 'true' to how the barrel extension should be sitting in there.
You don't have to get the Pacific tool to do this work. Some guys like that tool better because it is a tighter fit in most uppers (less slop = a more true surface with respect to the bore you are truing things up to) but there are others that make similar tools for a lot less money.
Here is an AR-Stoner brand tool that does that same job for less money (but is smaller in dia than the Pacific tool where it fits inside your upper): https://www.midwayusa.com/product/1006923823?pid=810457
Here is a Wheeler brand tool that does the same for even less money than that (and is smaller than the Pacific as already described): https://www.midwayusa.com/product/1007368790?pid=821295
A note about how those tools 'fit' and how that can be 'adjusted' - Box tape varies in thickness from brand to brand but is pretty consistent on the same roll. You can 'fatten' up a particular tool in that area for a better fit to your particular upper relatively inexpensively if you were really wanting to do so...
https://i.imgur.com/h0fTU1U.jpg
Barrel nut indexing shim instructions: https://www.ar15barrels.com/data/barrel-nut-index.pdf
If you need any help sorting all of that out with what YOU have on hand shim wise or nut wise and need help let me know and I will help you sort it out. The math there is not very hard to figure out.
If you already have the shims - Why not just do your OWN experiments on YOUR rifle with respect to the torque and see if you notice any changes?
Having read all of your posts in this thread - I think you ought to just go for it and go all in with all of your ideas.
A few comments about your previous posts:
Please don't try to true your receiver face like you mentioned. You are going to end up with a flat surface that is cocked to one side or the other and not 'true' to how the barrel extension should be sitting in there.
You don't have to get the Pacific tool to do this work. Some guys like that tool better because it is a tighter fit in most uppers (less slop = a more true surface with respect to the bore you are truing things up to) but there are others that make similar tools for a lot less money.
Here is an AR-Stoner brand tool that does that same job for less money (but is smaller in dia than the Pacific tool where it fits inside your upper): https://www.midwayusa.com/product/1006923823?pid=810457
Here is a Wheeler brand tool that does the same for even less money than that (and is smaller than the Pacific as already described): https://www.midwayusa.com/product/1007368790?pid=821295
A note about how those tools 'fit' and how that can be 'adjusted' - Box tape varies in thickness from brand to brand but is pretty consistent on the same roll. You can 'fatten' up a particular tool in that area for a better fit to your particular upper relatively inexpensively if you were really wanting to do so...
https://i.imgur.com/h0fTU1U.jpg
Barrel nut indexing shim instructions: https://www.ar15barrels.com/data/barrel-nut-index.pdf
If you need any help sorting all of that out with what YOU have on hand shim wise or nut wise and need help let me know and I will help you sort it out. The math there is not very hard to figure out.
love the gratuitous pic of fido!
Thunderpigeon
02-17-22, 07:37
Here is what Criterion Barrels recommends:
https://www.youtube.com/watch?v=XHxU8VUAHOY
https://www.youtube.com/watch?v=aSi75yrTIKQ
After you watch the videos be sure to read the comments. Criterion responds to several comments.
If you already have the shims - Why not just do your OWN experiments on YOUR rifle with respect to the torque and see if you notice any changes?
Having read all of your posts in this thread - I think you ought to just go for it and go all in with all of your ideas.
I would love to see incremental torque value accuracy testing out of a mechanical mount/jig. My personality/mind assumes everything is bull crap until proven otherwise. (Obviously, extreme torque values would be bad, but within the 30-75 range would be interesting)
If you already have the shims - Why not just do your OWN experiments on YOUR rifle with respect to the torque and see if you notice any changes?
Having read all of your posts in this thread - I think you ought to just go for it and go all in with all of your ideas.
A few comments about your previous posts:
Please don't try to true your receiver face like you mentioned. You are going to end up with a flat surface that is cocked to one side or the other and not 'true' to how the barrel extension should be sitting in there.
You don't have to get the Pacific tool to do this work. Some guys like that tool better because it is a tighter fit in most uppers (less slop = a more true surface with respect to the bore you are truing things up to) but there are others that make similar tools for a lot less money.
Here is an AR-Stoner brand tool that does that same job for less money (but is smaller in dia than the Pacific tool where it fits inside your upper): https://www.midwayusa.com/product/1006923823?pid=810457
Here is a Wheeler brand tool that does the same for even less money than that (and is smaller than the Pacific as already described): https://www.midwayusa.com/product/1007368790?pid=821295
A note about how those tools 'fit' and how that can be 'adjusted' - Box tape varies in thickness from brand to brand but is pretty consistent on the same roll. You can 'fatten' up a particular tool in that area for a better fit to your particular upper relatively inexpensively if you were really wanting to do so...
https://i.imgur.com/h0fTU1U.jpg
Barrel nut indexing shim instructions: https://www.ar15barrels.com/data/barrel-nut-index.pdf
If you need any help sorting all of that out with what YOU have on hand shim wise or nut wise and need help let me know and I will help you sort it out. The math there is not very hard to figure out.
Thanks brother. Good looking pup!
Each KAC URX4 that I have purchased came with two separate installation instructions. One says 60-70ft/lbs (+\-5) the other says 60-140 ft-lbs.
In machinists books, thread type, thread pitch, thread engagement depth, and material dictates max torque. If the makers of parts don't understand the material sciences, then shame on them.
140 on soft aluminum AR upper threading, seems like recipe for stripped threads. If the nut needs to be indexed, I would go near 50lb-ft and then advance nut to proper index.
I would love to see incremental torque value accuracy testing out of a mechanical mount/jig. My personality/mind assumes everything is bull crap until proven otherwise. (Obviously, extreme torque values would be bad, but within the 30-75 range would be interesting)I trust Bill Alexander, who has built a lot of accurate ARs.
Torque at the minimum end of GI torque range. Bed with a particular blue loctite.
He was also not a fan of lapping the face of upper receivers. His comment was that unless it's grossly out of spec the nose will deform under the clamping pressure of the much harder barrel nut. Which has multiple threads clamping it down.
Also explained the geometry of the barrel extension to receiver fit prevents very much canting at all. So unless the receiver is grossly out of spec, even if the receiver face is not exactly perpendicular to the bore axis it should not change point of impact.
It's just not possible for the assembly to get that far out of whack in terms of degrees. I did the math on this once in the past arguing with constructor before agreeing to disagree.
I could see an argument for unequal pressure affecting barrel harmonics, heat expansion, etc. for grossly out of spec upper receivers.
I've read here anecdotal reports of people who had rifles that shot left and lapped the nose and it shot straight. But I've never seen any objective testing.
Constructor, and several other accuracy oriented smiths do swear by it. I guess the worst thing it could do is reduce corrosion resistance by taking off the endonizing.
But the very fact that three different tools have different dimensions for the part that goes in the bore axis tells you that even with the tool it's not getting it truly perpendicular like a lathe would.
fedupflyer
02-17-22, 18:12
I would love to see incremental torque value accuracy testing out of a mechanical mount/jig. My personality/mind assumes everything is bull crap until proven otherwise. (Obviously, extreme torque values would be bad, but within the 30-75 range would be interesting)
With the way this thread is going, a few would try all kinds of torque values and use a basic red dot and 55g wolf ammo while shooting offhand to determine the effects.
Okie should be along anytime now to school us.
I trust Bill Alexander, who has built a lot of accurate ARs.
Torque at the minimum end of GI torque range. Bed with a particular blue loctite.
He was also not a fan of lapping the face of upper receivers. His comment was that unless it's grossly out of spec the nose will deform under the clamping pressure of the much harder barrel nut. Which has multiple threads clamping it down.
Also explained the geometry of the barrel extension to receiver fit prevents very much canting at all. So unless the receiver is grossly out of spec, even if the receiver face is not exactly perpendicular to the bore axis it should not change point of impact.
It's just not possible for the assembly to get that far out of whack in terms of degrees. I did the math on this once in the past arguing with constructor before agreeing to disagree.
I could see an argument for unequal pressure affecting barrel harmonics, heat expansion, etc. for grossly out of spec upper receivers.
I've read here anecdotal reports of people who had rifles that shot left and lapped the nose and it shot straight. But I've never seen any objective testing.
Constructor, and several other accuracy oriented smiths do swear by it. I guess the worst thing it could do is reduce corrosion resistance by taking off the endonizing.
But the very fact that three different tools have different dimensions for the part that goes in the bore axis tells you that even with the tool it's not getting it truly perpendicular like a lathe would.
I agree with this in theory and always torque right past minimum threshold but I've seen also seen barrels that shot very well with torqued nuts that were on the other end of the spectrum.
I trust Bill Alexander, who has built a lot of accurate ARs.
Torque at the minimum end of GI torque range. Bed with a particular blue loctite.
He was also not a fan of lapping the face of upper receivers. His comment was that unless it's grossly out of spec the nose will deform under the clamping pressure of the much harder barrel nut. Which has multiple threads clamping it down.
1) For many reasons, blue loctite is no good. A high-temp hard silicone will be better than almost all loctites. If removing the barrel is not in the service life, then high-temp epoxy (which is not ez to find)
2) I don't agree with his view on truing the upper nose. Deformation means it will put positional stress onto the barrel extension lip, creating a non-concentric clamping force (pushes barrel off axis). Heat cycles can then cause the barrel axis to "wobble" around. The best way to clamp, is to clamp faces that have "flattest" mating surfaces. Hence, flat on flat, or int and ext matching radius, etc.
I also think you would need way more than 50 or 60lb-ft of torque to achieve deformation past yield.
With the way this thread is going, a few would try all kinds of torque values and use a basic red dot and 55g wolf ammo while shooting offhand to determine the effects.
Okie should be along anytime now to school us.
Yes. This thread is retarded and refuses to die.
1) For many reasons, blue loctite is no good. A high-temp hard silicone will be better than almost all loctites. If removing the barrel is not in the service life, then high-temp epoxy (which is not ez to find)
You missed the part about "a specific blue loctite"... It's not your regular loctite, it's a specific bedding compound
2) I don't agree with his view on truing the upper nose. Deformation means it will put positional stress onto the barrel extension lip, creating a non-concentric clamping force (pushes barrel off axis). Heat cycles can then cause the barrel axis to "wobble" around. The best way to clamp, is to clamp faces that have "flattest" mating surfaces. Hence, flat on flat, or int and ext matching radius, etc.
I also think you would need way more than 50 or 60lb-ft of torque to achieve deformation past yield.
I would sort of agree with you for un-square receiver faces.
And also that flat is better than non-flat. But not due to misalignment, but due to unequal stress and harmonic impact, etc.
If I was that concerned about it I would not use a receiver that did not have a perpendicular / square nose.
And if I did feel the need to true one up, I would do it in a lathe because there's enough variability in the tools that you are kind of diluting yourself into thinking you have it square as well.
But we are back to everyone's feelings and conjecture, I have never seen an objective repeatable test that showed a significant benefit.
Yet we know that removing the andanizing not only creates a place that corrosion can start, but also removes the hardend surface of the aluminum.
As to yield strength, you need to remember that torque is not PSI. Torque creates PSI due to the wedge clamping effect of the threads, but the PSI also is determined by the surface area being acted on. Which is very small in a non-square receiver nose.
I still stay away from super high torque values on the barrel nut, and have good results since then. This is not low, just not on the high end or higher as the likely impact on stress and harmonics will be magnified.
So I kind of put the receiver face truing that smiths can sell as pixie dust and hobbyist can also do. Probably harmless, but I'd rather buy a higher quality upper receiver (Lol MT, AA, DD) and not have to deal with it. But I've never had an issue even with aeroprecision uppers.
the AR-15 Junkie
02-18-22, 17:33
So did the source for BCM barrels ever get determined?
So did the source for BCM barrels ever get determined?
It's either some secret or so obvious no one wants to say it out loud.
I have no clue and came to find out more and ran into these strange responses which are baffling...
but I'd rather buy a higher quality upper receiver (Lol MT, AA, DD) and not have to deal with it. But I've never had an issue even with aeroprecision uppers.
You ever checked one of any of those?
Have you ever even used one of the tools we are discussing? (actually used with your hands - not just 'watched a youtube video')
The source is the Earth and the mine that found the minerals.
You ever checked one of any of those?
Have you ever even used one of the tools we are discussing? (actually used with your hands - not just 'watched a youtube video')
I have a Pacific Tool and Gauge lapping tool. I figured they are a tool and gauge company so it ought to be fairly true.
I use regular valve lapping compound and coat the inside 'bearing walls' of the upper liberally with moly grease (I tried coating the tool itself first time - not really a critical thinker, am I?) I clamp the receiver in an upper receiver vise block and use a variable speed drill at very slow speed.
Every now and again (often) check the results and use a small tool to replenish lapping compound - I use a slice off the edge of a plastic bondo scraper which I also used when lapping valves on go kart engines. Don't remove the tool more than an inch or so to avoid getting grease mixed up with lapping compound - you don't want to lap the inside of the upper.
The first couple I did I went until all anodizing was removed. After watching a you-tube video I started just going until about 2/3 - 3/4 was removed and I could tell the anodizing remaining had been lapped. After I get everything cleaned up, I set the receiver onto its trued end on my plate glass 'surface plate' to check for wobble.
For cleanup I use kerosene, then brake cleaner, then balistol, then dry as much as I can then let it set a while. I get aeroshell all over everything when I'm assembling, and then I thoroughly lube the receiver with EWL2000 or similar.
All told minus the receiver setting for a while to dry out, the whole procedure takes less than a half hour - unless you are like me most of the time and have to remember where you put everything.
Does it improve accuracy? Logically, it might, but it probably does more to ensure your windage remains pretty much centered in your adjustments. I'm sure it doesn't hurt anything, and the folks that I've put together rifles for think they've really got some custom build stuff going on, so you can't beat that, LOL,
Yes. This thread is retarded and refuses to die.
The OP must be a visionary and knew how this thread would go. He immediately asked the mods to delete this thread….
You ever checked one of any of those?
Have you ever even used one of the tools we are discussing? (actually used with your hands - not just 'watched a youtube video')
You should know the answer to this... No, just like I don't need to use KNS pins to know they are a faddish solution to a very narrow case of problems that most will never experience.
I would suggest reading through this old thread: https://www.m4carbine.net/archive/index.php/t-127822.html
Which covered multiple years, and many build SME's commented (Grant, Failure to Stop, Ned Christianson, Lysander, AR-15 barrel guy, Constructor, etc. And even Markm, who had some interesting results). The short version is that it (mostly) does not hurt, but is a sign the user has not thought through the geometry of how the barrel flange and receiver extension interface with the upper receiver. If both are in spec, it is physically impossible for the receiver nose to cause significant windage misalignments. But there is room to disagree on this, you do you.
Likewise, how do you know the flange is true? The threads? Even the barrel nut? The SME's who build thousands of rifles say that all can be out of spec, non-true.
And nearly all the truing tools are undersized for the part of the receiver that the extension mates with. Instead, they index off the very rear of the receiver bore. Yet the barrel indexes on the first inch or so of the receiver bore. Apparently both the front of the receiver bore and the rear are machined in one operation and are *usually* in alignment. But, how do you know?
Finally, a bunch of folks who specialize in accurate rifles did not advocate or even sell the service. Yet they do other operations. Specifically:
- White Oak- Does not, and does not even offer the service as optional
- Compass Lake- Does not, and does not even offer the service as optional
- AMU did not as of 2012 (don't know more recently)
And the people who advocate the strongest for it are ones who sell it as a service. One well known vender who comments here indicates he's done several thousand. But also acknowledges it is not for accuracy, but to ensure equal bolt lug engagement.
If you are passionate about the topic it's worth a read. (I'm not, just recalled that thread). To me there were some pretty clear takeaways. And I had already done the math/trig/geometry on the receiver to barrel extension interface to see how many degrees it could possibly be off separately, so it was a good check when Lysander did similar.
Others also confirmed the nose/face deforms easily under the clamping pressure of the flange/barrel nut. Think of it like a crush washer.
Markm did a test, hoping it would fix a badly misaligned carbine. It did not.
Multiple SME's said the barrel extension to receiver interface is what really matters. It should be snug, even tight. And ideally an interference fit such that you have to heat the receiver slightly so it expands enough for the extension to slide in. And that most windage issues are barrel indexing, FSB or warping related.
And best advice from folks who know: If you care about shooting bug-nuts, then get a receiver where the truing/dimensional work was done ahead of anodizing. And all dimensions were checked.
I have a Pacific Tool and Gauge lapping tool. I figured they are a tool and gauge company so it ought to be fairly true.
Next to a proper setup in a lathe, the PTG tool is probably what I'd use.
The OP must be a visionary and knew how this thread would go. He immediately asked the mods to delete this thread….
Yep, we are far afield. But it got into receiver truing, etc. And this is M4 Carbine, not "I_shoot_bug_holes_off_the_bench".net anyway, so it's odd that receiver truing comes up so passionately.
The OP must be a visionary and knew how this thread would go. He immediately asked the mods to delete this thread….
ha, true that, it's become a full on dk swinging contest with zero value and all opinion. In what is fast becoming the norm here, it's gone down the arfcom path. I think some posters just like to see their name in a thread
I need to change my settings as I keep updates to this thread and it seems to be the only one I keep getting emails on ha
So did the source for BCM barrels ever get determined?
It doesn’t matter if you are talking about guns, golf clubs, fishing rods or lawn mowers, everybody likes name brand components. If a company is using top end, name brand components, his marketing people are going to be shouting that from the roof tops. Everyone wants Krieger barrels and G. Loomis rod blanks.
But if the company is using parts that may be acceptable but lower grade, they are much less likely to be transparent about that.
Before the teeth nashing begins, this isn’t a knock on BCM. Just a general fact in manufacturing and marketing.
It always made sense to me that they got them off FN. That's not gospel, just my speculation.
There's only a handful of CHF's here in the states. FN and Daniel Defense?
Even if they do use a good enough barrel, I am sure BCM QC's them more carefully than many of the other manufactures that use them.
Rifleman_04
02-19-22, 15:01
The gun industry is silly. Why is this such a secret? Who friggin cares. 12 pages and those who don’t know still don’t and those that do still think they are special.
It always made sense to me that they got them off FN. That's not gospel, just my speculation.
There's only a handful of CHF's here in the states. FN and Daniel Defense?
Even if they do use a good enough barrel, I am sure BCM QC's them more carefully than many of the other manufactures that use them.
I think there are a few hammer forges now. Steyr, FN, DD, Geissele, Ruger. And Sig. I know the word a couple years ago was that BCM's barrels come from FN, to their specs.
I'm pretty sure that's the answer, so now that we know, can we close this thread?
I think there are a few hammer forges now. Steyr, FN, DD, Geissele, Ruger. And Sig. I know the word a couple years ago was that BCM's barrels come from FN, to their specs.
I'm pretty sure that's the answer, so now that we know, can we close this thread?
I was thinking more about stateside? Does steyr own one stateside?
Geissele owns one?
A barrel CHF is a big piece of machinery.
I was thinking more about stateside? Does steyr own one stateside?
Geissele owns one?
A barrel CHF is a big piece of machinery.Yeah, you're right about Steyr. AFAIK, Geissele has one. They claim to forge their own barrels in house.
I was thinking more about stateside? Does steyr own one stateside?
Geissele owns one?
A barrel CHF is a big piece of machinery.
The Steyr AUG A3 M1's all have cold hammer forged barrels made here in the US. The only thing I don't like about mine is that it's not chrome lined.
Daniel Defense also showed a video of their cold hammer forging machine making barrels in one of their tour videos on YouTube.
BCM at one point, early on, stated that their barrels came from FN.
There are people that have been forging barrels for decades not being listed here.
Sent from my iPhone using Tapatalk
So did the source for BCM barrels ever get determined?
Who makes barrels for BCM?
FN
Who makes barrels for BCM? Without prove it’s just internet speculation and chatter.
was on looking for something yesterday and stumbled across this. Kind of funny but not surprising at the same time for anyone that has had bcm set ups. Certainly not Gospel but take it as you may and get ready for the buttheurt
https://www.youtube.com/watch?v=5lTFMFPzp68
was on looking for something yesterday and stumbled across this. Kind of funny but not surprising at the same time for anyone that has had bcm set ups. Certainly not Gospel but take it as you may and get ready for the buttheurt
https://www.youtube.com/watch?v=5lTFMFPzp68
I dont know why anyone would get buttheurt. You are buying the BCM for reliability and QC. Things that are nonexistent in the DPMS. They are also two different barrel profiles - the BCM is lightweight and the DPMS is socom. Pretty crappy results for a socom barrel. A colt socom will shoot moa or under all day.
I dont know why anyone would get buttheurt. You are buying the BCM for reliability and QC. Things that are nonexistent in the DPMS. They are also two different barrel profiles - the BCM is lightweight and the DPMS is socom. Pretty crappy results for a socom barrel. A colt socom will shoot moa or under all day.
slow down on the moa as no, that is not true unless you are using match ammo. Socom barrels are not going moa with your ranger fodder 55gr like most in the video. Consistently shooting moa with one will require finding the ammo your barrel likes and even then, it's shooter skill. Those barrels while certainly more accurate than the typical rack grade $hit, are not magic and I'm not counting your cherry picked or methodical 5 shot group, you need to heat that barrel up and then shoot to see what its' capable of 'all day'. I still have 3 of them, had probably 10 or so including FN. Hell even Molon used match grade handloads and just got MOA. With the 193, he was at 1.6 or so. As for the profiles, he wasn't shooting enough to string out that lightweight barrel. DPMS barrels have a decent rep for accuracy from first hand and years of seeing and reading range reports so even before I watched it, I knew it would do well but surprised the BCM did not do better.
Yes, I like my “SOCOM” barrels, but a 10 shot MOA group, I have not shot. And its not like I’m terrible.
Yes, I like my “SOCOM” barrels, but a 10 shot MOA group, I have not shot. And its not like I’m terrible.
same here, I'll always get one fking flyer and it's always the last two lol
I dont know why anyone would get buttheurt. You are buying the BCM for reliability and QC. Things that are nonexistent in the DPMS. They are also two different barrel profiles - the BCM is lightweight and the DPMS is socom. Pretty crappy results for a socom barrel. A colt socom will shoot moa or under all day.
He didn't really know shit about what sort of DPMS barrel he even had. Pretty much offered no info about it.
His barrel was definitely not Socom profile. (no notches where they should have been in the part of the barrel he did show)
He was 'not sure' about the twist, not sure if chrome lined or not, not really specific about his barrel profile under the hand guards. He claimed it was the DMPS heavy but did not show any sort of evidence (or knowledge of how to even tell the difference between any of them)
About the 14 minute mark for the part about the chrome lining (or not)...
He has no clue what he even has from DMPS and does pretty well at admitting it. At 1:05 he claims it to be a $200.00 DPMS complete upper. (not believing that)
How does a guy not even 'look' to see if he has chrome or not or 'look' to see what exact sort of barrel profile he has?
Twist rate is always going to be marked on a DPMS barrel...
https://i.imgur.com/Gi6qTRm.jpg
Colt HBAR in middle of that picture for reference...
He didn't really know shit about what sort of DPMS barrel he even had. Pretty much offered no info about it.
His barrel was definitely not Socom profile. (no notches where they should have been in the part of the barrel he did show)
He was 'not sure' about the twist, not sure if chrome lined or not, not really specific about his barrel profile under the hand guards. He claimed it was the DMPS heavy but did not show any sort of evidence (or knowledge of how to even tell the difference between any of them)
About the 14 minute mark for the part about the chrome lining (or not)...
He has no clue what he even has from DMPS and does pretty well at admitting it. At 1:05 he claims it to be a $200.00 DPMS complete upper. (not believing that)
How does a guy not even 'look' to see if he has chrome or not or 'look' to see what exact sort of barrel profile he has?
Twist rate is always going to be marked on a DPMS barrel...
https://i.imgur.com/Gi6qTRm.jpg
Colt HBAR in middle of that picture for reference...
You are correct. Looks like midway calls it a Heavy Contour Barrel - 1:9 - https://www.midwayusa.com/product/1003454270
What are you other 2 in your pic?
You are correct. Looks like midway calls it a Heavy Contour Barrel - 1:9 - https://www.midwayusa.com/product/1003454270
What are you other 2 in your pic?
You have no way of knowing if the one in your link matches what he had in the video. The video guy is too dumb to even know what he has.
Heck, the item description in that ad does not even match what they have in their picture. (threaded barrel in picture vs non-threaded target crown in description)
The DPMS in my picture (far left) has very nice chrome lining. (was optional back when they sold these but yes, they offered it and the company that did that for them did not screw around)
Have you ever compared their chrome to what one normally finds on a Colt like I did?
What about shooting them both side by side and comparing? (A 1:9 DPMS heavy with chrome vs a 1:9 Colt heavy with chrome like in my picture)
Yes, I like my “SOCOM” barrels, but a 10 shot MOA group, I have not shot. And its not like I’m terrible.
For me, a 10 shot group doesn't represent a barrel's ability because I can't lay still that long without getting fatigued. On a semi-auto, it's usually shots 3 through 5 where I settle down... and then I get antsy after that.
All I know is the two BCM barrels I have, outshoot me, and have been stone cold reliable.
I'm good.
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