View Full Version : Which BCM barrel
I'm building a precision AR and don't know too much about barrels. I was looking at the 20" barrels on the BCM website and was hoping some one could answer a question, will I get more accuracy out of the standard barrel with a 1/7 twist or the SAM R barrel with the 1/8 twist?
Sent from my LG-LS720 using Tapatalk
I'm building a precision AR and don't know too much about barrels. I was looking at the 20" barrels on the BCM website and was hoping some one could answer a question, will I get more accuracy out of the standard barrel with a 1/7 twist or the SAM R barrel with the 1/8 twist?
Sent from my LG-LS720 using Tapatalk
Go with their SS barrels. I personally run the 16."
C4
My theory is if I put the money in the barrel, trigger and scope and can get by with spending less on the other components.
Sent from my LG-LS720 using Tapatalk
What ammo will you shoot? What distances will you want to shoot? What are you accuracy expectations?
Ammo will be an experiment to see what performs the best. There is a range close to my house that goes out to a thousand yards, I'm hoping to be accurate to six hundred max. I've never done long distance so I don't want to spend beyond my skills if that makes sense.
Sent from my LG-LS720 using Tapatalk
But I would also like to have something decent to start with.
Sent from my LG-LS720 using Tapatalk
With a decent scope, ANY BCM barrel (but probably SS), and 77 gr SMKs, you'll be shooting 600 yards no problem.
My WOA 18" varmint upper with 1 in 7" twist on top of a Colt LE 6920 lower with a SSA-E trigger shoots less than 1/2" five shot groups at 100 yds. Give them a call they may have them in stock and ready to go. The 20" are only $285 with fitted gas manifold.
http://www.whiteoakarmament.com/xcart/product.php?productid=17824&cat=250&page=2
Go with their SS barrels. I personally run the 16."
C4
Sorry for the rookie question. Is the ss410 16" 1/8 twist barrel a good one for a precision ar? Thanks!
Steel head
07-27-14, 11:05
Sorry for the rookie question. Is the ss410 16" 1/8 twist barrel a good one for a precision ar? Thanks!
A big YES!
I personally like the 18's a bit better but 16's are more than capable shooting at 500+ yards and making grin groups.
Sorry for the rookie question. Is the ss410 16" 1/8 twist barrel a good one for a precision ar? Thanks!
Yes.
C4
Thank you for the quick replies!
Don't be afraid of long distance. If I can do it out to 1,000 yds. you can too. I shoot at 1,000 yds. with my bolt gon in 6mm Norma BR.
I put a custom turret label on my Bushnell 4.5-18x40mm which is on top of my WOA 18" varmint with 1 in 7" twist which is fluted to save some weight. It shoots less than 1/2" five shot groups at 100 yds. I still have to get to the range to see how accurate it is.
Singlestack Wonder
07-30-14, 08:35
Go with the BCM stainless barrel with SAM-R chamber.
Go with the BCM stainless barrel with SAM-R chamber.
What's a SAM-R chamber? (I've never tried a SS BCM Barrel)
I believe it's a happy medium between Wylde and NATO spec.
I'm building a precision AR and don't know too much about barrels. I was looking at the 20" barrels on the BCM website and was hoping some one could answer a question, will I get more accuracy out of the standard barrel with a 1/7 twist or the SAM R barrel with the 1/8 twist?
Sent from my LG-LS720 using Tapatalk
I have been planning on using a 20" BCM SS barrel too. But the more I research the less I think I am going down that road. I am now thinking using a 16" BCM SS barrel.
It seem like there are plenty of people shooting 5-600 yards no problem with a 16". I can always come back to the 20" if I want to really reach out there.
BrigandTwoFour
08-05-14, 23:13
I would just throw out there that if you are planning on learning to shoot accurately at range, you might be better served by a standard chrome lined barrel in the mean time. Quality standard barrels (like BCM's standard or CHF) are still quite capable of great accuracy in the hands of a good shooter with good ammo. Unless you yourself are able to shoot better than 1 MOA, then you are not going to get the benefit of a nice SS barrel and would be better served getting something more standard and spending A LOT of quality ammo and quality range time.
I was going down the same road you are until I watched a guy take a Colt 6920 with a SSA trigger and 18x scope and print three sub-MOA ten-round groups with three different match loads (MK262, 75 gr TAP, and 77gr Norma).
I'm going to disagree with the above. Everyone can always benefit from higher quality components, even the worst of shooters. Don't waste your time with rack grade components (I know BCM is high quality, hang with me). If you put in the time you'll out shoot that barrel soon enough and you'll wish you had stuck with the SS. It will be cheaper in the long run. Yes, people have done great things with normal stuff. But why limit yourself? If you have the means, go for it. That way you'll know that the only thing holding you back is you, and not the equipment.
You do realize that stainless barrels will generally wear and lose accuracy faster than chrome-lined barrels, right? As good as SS is, with the results that myself and others see with good chrome lined barrels there isn't much necessity. Of course, one needs to define what it is what they are actually wanting it to do.
I'm going to disagree with the above. Everyone can always benefit from higher quality components, even the worst of shooters. Don't waste your time with rack grade components (I know BCM is high quality, hang with me). If you put in the time you'll out shoot that barrel soon enough and you'll wish you had stuck with the SS. It will be cheaper in the long run. Yes, people have done great things with normal stuff. But why limit yourself? If you have the means, go for it. That way you'll know that the only thing holding you back is you, and not the equipment.
Yep, I have 2 non-match grade barrels that will shoot sub-moa with my 77gr handloads. One is chrome lined and the other is salt-bath nitride (melonite).
I still have my share of stainless match grade barrels, but a good, quality chrome lined barrel can serve you well. I know of a few members that bang steel at 1,000 yds with a 14.5 BCM-ELW barrel and handloads.
Decided to go with the standard BCM 20in barrel. Couldn't pass up the deal with the free bcg
I've finally finished this rifle, only problem is I'm having some minor problems with it cycling. Here are the specs:
BCM 20" rifle length barrel
BCM upper
BCM Bolt and BCG
Yankee Hill folding front site gas block
Yankee Hill rifle length free float rail
Spike lower
CMMG parts kit (will be replacing trigger with SSA-E)
Leaper UTG A2 rifle stock kit (this is where I went really cheap and think it might be part of the issue)
Ammo use:
Independence 55gr 5.56
PMC XTac 55gr 5.56
PMC Xtac 62gr 5.56 green tip
PMC Bronze 223
ZQI 62gr 5.56 (this is the only ammo I have had issues with)
When I first took the rifle out it was short stroking bad with the ZQI, you could see where I was leaking gas behind the gas block, so I reinstalled it making sure everything was lined up and tight (blue Loctite used on screws).
Took the rifle out today and it would cycle but would not feed the next round sometimes, trigger would reset, bolt would go into battery, but just click no bang. Again this was only with the ZQI ammo. Is there that much difference in the pressure of these rounds to cause this? At first I thought maybe the spring and buffer were maybe the cause, I did go ahead and order a new buffer and spring today from BCM. I run the ZQI in my Colt 6920 which I installed a low pro gas block on and it runs perfectly.
.46caliber
01-31-15, 17:30
What buffer and spring?
Sent from my Nexus 4 using Tapatalk
Don't know anything about ZQI , but since that is the only one and it operates fine with PMC.
I would say it the ammo.
It might work fine in the 6920 since it is a carbine gas system.
How about an adjustable gas block?
Does a carbine system require less or more pressure to operate. The spring and buffer are what ever came with the stock, they are just regular A2 parts, nothing fancy. They are being replaced just to eliminate the possibility of them being the culprit.
How about an adjustable gas block?
Shouldn't need one .
I run a 20" BCM also, I can run Wolf all day long.
I forgot to mention the ejection pattern is very consistent at 4 o'clock about 12 feet away.
Does a carbine system require less or more pressure to operate. The spring and buffer are what ever came with the stock, they are just regular A2 parts, nothing fancy. They are being replaced just to eliminate the possibility of them being the culprit.
It is not about what is required.
It does operate at a higher pressure then a rifle gas system.
That is the ammo I forgot, it shoots the Wolf Gold 55gr just fine.
.46caliber
01-31-15, 18:50
Does a carbine system require less or more pressure to operate. The spring and buffer are what ever came with the stock, they are just regular A2 parts, nothing fancy. They are being replaced just to eliminate the possibility of them being the culprit.
I'd get a quality RE, spring and buffer properly spec'd for a rifle length gas system. I'd also replace the gas block assuming its their clamp-on unit.
The question about pressure is off-kilter. There isn't different pressure ammo for carbine vs. rifle systems. Port size and placement, and the block in the case of an adjustable, determine how much gas is sent back. With the proper buffer and spring and a good sraled gas system, the gun should cycle on any quality ammo that is loaded correctly.
Sent from my Nexus 4 using Tapatalk
I'd get a quality RE, spring and buffer properly spec'd for a rifle length gas system. I'd also replace the gas block assuming its their clamp-on unit.
The question about pressure is off-kilter. There isn't different pressure ammo for carbine vs. rifle systems. Port size and placement, and the block in the case of an adjustable, determine how much gas is sent back. With the proper buffer and spring and a good sraled gas system, the gun should cycle on any quality ammo that is loaded correctly.
Sent from my Nexus 4 using Tapatalk
Spring and buffer are being replaced with parts from BCM. I am trying to go for a SAM-R clone that is why I used the Yankee hill gas block, if I could find a KAC block for a reasonable price I'd use it. I'm not planning on using ZQI ammo I just like to try different ammo to make sure it cycles with anything.
.46caliber
01-31-15, 19:34
Spring and buffer are being replaced with parts from BCM. I am trying to go for a SAM-R clone that is why I used the Yankee hill gas block, if I could find a KAC block for a reasonable price I'd use it. I'm not planning on using ZQI ammo I just like to try different ammo to make sure it cycles with anything.
The few range reports I've seen on ZQI have been good. I've got a few boxes, but yet to test.
PMC .223 is usually pretty mild stuff. The ZQI 5.56 would have to be off to produce less pressure than PMC .223. That is unless PMC has changed their .223 load. You could use a chrono to verify.
Independence 5.56 is full pressure and sometimes over. Very hot stuff. There's 3 threads or so on it within the Ammunition & Reloading sub-forum.
I assume the extension was whatever came with the UTG kit and you'll be swapping that with a BCM.
Sent from my Nexus 4 using Tapatalk
I did not order a new buffer tube, is that something that could be out of spec or cause problems normally?
Another question, so which system produces more gas pressure, a rifle or carbine? A rifle does produce more velocity correct?
Another question, so which system produces more gas pressure, a rifle or carbine?
Carbine, gas port is closest to the BCG, the rifle gas port is the farthest away. And midlenght in the middle.
Gas port size can vary depending Mfg, that can change how some systems behave.
If you search this site there is plenty of talk about the pressures that each one operate at.
.46caliber
01-31-15, 19:57
I did not order a new buffer tube, is that something that could be out of spec or cause problems normally?
Another question, so which system produces more gas pressure, a rifle or carbine? A rifle does produce more velocity correct?
They don't operate at different pressures. A 20" barrel yields higher velocities because the bullet is under pressure longer and continues to accelerate those next 4" of barrel. Look at bolt action rifles that have no gas system.
Sent from my Nexus 4 using Tapatalk
They don't operate at different pressures.
I think he means the gas system.
Sent from my SM-G900V using Tapatalk
I think he means the gas system.
Sent from my SM-G900V using Tapatalk
Yes, I guess I'm wondering which gas system, carbine or rifle, is causing more force on the bolt carrier? Trying to figure out why the ammo cycles a carbine and not a rifle.
I'll second the 16" SS410. I picked up a 'sale' upper from BCM with the DD lite rail, puts any MK12 I have shot to shame with MK262. It is a .75MOA barrel when it is hot, and I have shot many sub .5 MOA groups with it.
Txinfidel,
Do you use exclusively mk 262? Is it your own make or bought somewhere? Are there other cartridges that do well in it?
I just ordered the 16"ss410. Should be here tomorrow. Wondering what it is gonna like.
T&E'd a SS410 16" KMR Upper and it was phenomenal. I never found a Cartridge it didn't like. It would bughole M855 @ 50m when a RDS was employed on her. Solid Sub-MOA.
Thanks HD. Good to know. That is the exact upper I ordered. I did it mainly because I was going to have a suppressor and wanted to mitigate POI shift. Wanted the thicker profile, but still lighter weight on a SPR type rifle. Had to sell off one of my ELW/KMR uppers to get this done.
Thanks HD. Good to know. That is the exact upper I ordered. I did it mainly because I was going to have a suppressor and wanted to mitigate POI shift. Wanted the thicker profile, but still lighter weight on a SPR type rifle. Had to sell off one of my ELW/KMR uppers to get this done.
Perfect choice and reasoning. This is probably one of the smartest Profiles available on an AR Barrel.
Got to take it out today. This is all suppressed, (YHM SS QD)
It really liked Freedom 55gr and Hornady 75 gr BTHP. 23.5 gr varget.
best grp
http://i1100.photobucket.com/albums/g410/Titleofliberty/20150210_162034_zpsvauwmqqc.jpg (http://s1100.photobucket.com/user/Titleofliberty/media/20150210_162034_zpsvauwmqqc.jpg.html)
http://i1100.photobucket.com/albums/g410/Titleofliberty/20150210_162015_zpsr2ncqrz3.jpg (http://s1100.photobucket.com/user/Titleofliberty/media/20150210_162015_zpsr2ncqrz3.jpg.html)
average grp m855 (wolf gold was about here too)
http://i1100.photobucket.com/albums/g410/Titleofliberty/20150210_153924_zpsqk15fegu.jpg (http://s1100.photobucket.com/user/Titleofliberty/media/20150210_153924_zpsqk15fegu.jpg.html)
I only had one target. so I had to get creative...sharpie where I was aiming (on middle points between orange bullseyes).
Overall, I am happy with grps. Only problem is the shooter was a spaz.
When or if you get the chance, try some .223 FGMM 69 & 77 SMK, and funny enough, Hornady (Varmint or custom?) 55gr Vmax... those have all shot super tight for me.
I've also had good luck out of the Hornady Match 75gr BTHP .223 stuff.
Shot a .65" 5 Shot group @ 100y with BH Mk262 the other day...was really pleased with that!
These barrels (quality SS precision) normally shoot better than we can on most days!
Powered by vBulletin® Version 4.2.5 Copyright © 2024 vBulletin Solutions, Inc. All rights reserved.