View Full Version : Can a Rifle length work w/ .223?
I have recently switched gears and have been building some 20" rifle length guns because I really like how smooth they are in comparison to the carbine length system. The question is, is there a way to get these things to run reliably with lower pressure non-nato ammo. They work flawlessly with anything that is up to nato specs but I have only been able to get about 3 rounds out before a malfunction with anything that isn't. Is there a secret buffer/spring combination out there?
ForTehNguyen
11-12-11, 08:13
my BCM 20" upper works with wolf ammo, didnt do anything special its just the typical rifle buffer and spring
a 16" midlength will shoot just as smooth as a rifle upper probably. On my 16" middys I use H buffers and it shoots wolf and steel case fine.
Rifle length buffer/spring, stock assembly? or carbine?
ForTehNguyen
11-12-11, 10:05
my 20" has an A2 stock with rifle buffer and spring
my 16" middy has H buffer, carbine buffer tube, and spring
My old 20" Colt HBar ran fine with 223 or 5.56. My current 20" with Lothar-Walther barrel and carbine extension with carbine buffer also runs fine on 223 ammo.
223 ammo isn't "lower pressure". It's loaded to safe pressures in 223 SAAMI spec chambers. 5.56 chambers will give lower pressures with the same loads compared to a 223 SAAMI chamber
Mine eats any .223 or 5.56 I feed it. No special combo of buffer or spring needed. For reference, my rifle uses a Green Mountain barrel.
I'm assuming your rifle is short-stroking. How wide is your gas port? Is the FSB or gas block aligned with the gas port?
I am getting short stroking actually.
I've tried 2 colt uppers so far, one an A1 the other an A2, both 1960's era I was told. I mated them both with cavarms lowers, which I was told was carbine length RE, and tried from a carbine buffer up to an H3 buffer with no success. I didn't try rifle length because I didn't think you could with the cavarms lower. One LPK is a G&R the other a DD, with BCM re spring, buffers and BCG. Brownell's mags with either green or magpul followers.
Shoots great with m193 & ss109 regardless of buffer. PRVI, UMC and wolf are a no-go. Short strokes about every 3-4 rounds.
I have no Idea how wide the gas ports are, I assumed they were milsurp and in spec. since they were small hole, but anything is possible.
The FSB's appear straight to me, they definitely shoot straight enough. I'll pull one off to see if there's any indication of them being canted.
I have a green mountain barrel that I am in the process of putting an ACE ARFX stock on and before I do everything I wanted to see if I could get the cheaper stuff to work.
Traveshamockery
11-13-11, 20:18
My brother's 20" Palmetto State upper runs just fine on Remington UMC .223. It's on a lower with a carbine length buffer tube and a carbine buffer.
Carbine RE... Do they function on a rifle RE?
The gas port on the FSB could be slightly forward of the gas port on the barrel, just enough so that there's enough of a blockage so that the bolt carrier isn't getting enough gas when shooting with .223. That's what I was getting at.
They work flawlessly with anything that is up to nato specs but I have only been able to get about 3 rounds out before a malfunction with anything that isn't. Is there a secret buffer/spring combination out there?
A rifle system should work all day long with good .223 ammo. PMC Bronze and shit steel cased might choke it. But any decent .223 should run flawlessly.
Don't get into this aftermarket spring nonsense. If a gun needs some idiotic colored spring to run right.... replace the gun. :rolleyes:
I'm not using special springs, standard carbine or rifle. Guess I need to take'em down and do some inspecting. Thanks to all who responded.
What ammo are you running?... Like I said... some ammo, Like PMC bronze has the wrong propellant in it.
Stuff like that has choked my 20 inch guns. No one notices those problems because most people are shooting carbine or middy gas systems.
PMC bronze is one, PRVI mostly, some golden bear, winchester white box and I think I had some wolf classic rolling around the range bag. None of which offered anything different. About 3-4 rds. then a malfunction.
SilverTongueDevil
11-17-11, 17:39
My bone stock Colt Hbar A2 20inch barrel works just fine on Wolf, Silver bear PMC. Clean them Lube them and try different mags.
I did have a short stroke problem when I was shooting Tula crap out of old steel mag but when I loaded up a Pmag and re lubed her up she was up and running spitting some lube out but still running. Not the cleanest day of shooting Lube Plus Tula = muck and gunk..
I burned through all of the PMC ammo I bought on sale during the Magpul course. Zero issues with it.
What ammo are you running?... Like I said... some ammo, Like PMC bronze has the wrong propellant in it.
Stuff like that has choked my 20 inch guns. No one notices those problems because most people are shooting carbine or middy gas systems.
Yep. Works great in short gas systems. Robb Jenson is the one that pointed out it chokes in Rifles.
I went and tried mine, and sure enough... This was a few years back. It's possible they've changed the propellant since.
davidjinks
11-18-11, 07:18
OP
Not the same barrel length, however my MK12 runs all the .223 ammo I've put through it. The barrel is an 18" Douglas SPR barrel.
Animal_Mother556
11-18-11, 07:22
Yep. Works great in short gas systems. Robb Jenson is the one that pointed out it chokes in Rifles.
I went and tried mine, and sure enough... This was a few years back. It's possible they've changed the propellant since.
I bought about 800 rounds of PMC bronze sometime last winter. I shot about 600 of it through two different rifle length gas systems. No issues at all. So, maybe they have indeed changed their recipe.
So, maybe they have indeed changed their recipe.
I would hope so. It's really so easy to make ammo that runs a broad spectrum of gas systems.
These foreign banana's are constantly getting it wrong.
I just found two magazines with some of it loaded. We'll have to try it out and see.
I would hope so. It's really so easy to make ammo that runs a broad spectrum of gas systems.
These foreign banana's are constantly getting it wrong.
Phil has a little too... are you coming out tomorrow? You have some stuff you wanted to test right?
Is there a secret buffer/spring combination out there?
Rifle length installations can be more difficult.
In my experience I had to use a lower power buffer spring (Wolff recuced power) and in this case I used an Endine buffer (just because I had one) ~ it worked and I stopped there.
I took different springs to the range and tested until the combination worked.
I never had any problem with mid or carbine gas lengths.
The rifle had less power and I had to adjust to it.
Good Luck.
Rifle length installations can be more difficult.
They shouldn't be. Rifle should be the easiest.
In my experience I had to use a lower power buffer spring (Wolff recuced power) and in this case I used an Endine buffer (just because I had one) ~ it worked and I stopped there.
I took different springs to the range and tested until the combination worked.
I never had any problem with mid or carbine gas lengths.
The rifle had less power and I had to adjust to it.
Good Luck.
I would never settle on a gun that needed either a reduced power spring or a weird buffer.
Either the gun needs port work or has a gas leak, or the ammo is doo doo. And tuning a gun to run bad ammo is all kinds of lunacy to me.
Either the gun needs port work or has a gas leak, or the ammo is doo doo. And tuning a gun to run bad ammo is all kinds of lunacy to me.
Not in my case, I have heard others with similar reports on RL.
No denying it is a gas issue, did adjust the port size too.
FWIW, different ammo was used and all first class and includes match ammo.
Just passing on an experience is all.
The botom line is making it work.
Not in my case, I have heard others with similar reports on RL.
No denying it is a gas issue, did adjust the port size too.
FWIW, different ammo was used and all first class and includes match ammo.
Just passing on an experience is all.
The botom line is making it work.
What's the ammo and gun out of curiosity?
As others have said, there SHOULD be no issues.
An FSB / GB alignment issue is possible, just as somebody else mentioned. The gas port may also be on the small side.
Possible fixes:
Determine the size of the gas port. Figure out what it should be, and if it's not that, have it opened up.
*EDIT* Just saw that you have looked at the port size. Out of curiosity, what is it?
Or, try a JP LMOS...not an ideal fix, but it will probably work.
GeorgiaBoy
11-22-11, 17:03
I have run 2 magazines of Wolf for a function test my BCM 20" and it did fine- no issues.
I'm using a standard A2 stock configuration.
The_Hammer_Man
11-25-11, 04:29
Short stroking in 20" AR's ALMOST always attributable to:
A) Misaligned gas blocks
B) Out of spec gas ports
B) Improperly installed gas tubes ( this SEEMS like a no brainer but, it does happen!)
C) Incorrect buffer/spring combinations.
The "Fix"
1) Check the gas block offset from the barrels shoulder. The gap between the gasblock and the shoulder should be at least .035 to .036.
1a) Check to make sure the FSB/GB is straight up and down in relation to the gas port. All too often I've gotten rifle length AR's into the shop that had improperly installed gb's. (Stupid but true)
2) Using a wire guage check the size and continuity of the gas port. The size should be between 0.87-.093 depending on manufacturer.
A "continuity check" seems redundant but I've run across several barrels that had burrs in the gas port holes... thus blocking the flow.
This IS rare as hell but does happen. Soooo.. better to be sure it's not the issue.
3) Check to make sure the gas tube was installed right side up! I shit you not ! I've had several NIB rifles pass through my hands that had their gas tubes installed upside down.
If your still short stroking after checking and correcting the previous then either you are using some seriously wimpy ammunition OR your buffer/spring combination is too heavy/strong.
No fast fix for this issue. Grab several different rifle/carbine springs and buffers of varying weights and go to the range. (or the bang box in my case)
In my experience these have been the most common ways to fix the issue you're experiencing.
As always, YMMV
Regards,
TJ
This makes no sense. A rifle shouldn't be using anything other than a rifle spring and buffer or an A5 system if you want telescoping stocks.
Short stroking in 20" AR's ALMOST always attributable to:
A) Misaligned gas blocks
B) Out of spec gas ports
B) Improperly installed gas tubes ( this SEEMS like a no brainer but, it does happen!)
C) Incorrect buffer/spring combinations.
The "Fix"
1) Check the gas block offset from the barrels shoulder. The gap between the gasblock and the shoulder should be at least .035 to .036.
1a) Check to make sure the FSB/GB is straight up and down in relation to the gas port. All too often I've gotten rifle length AR's into the shop that had improperly installed gb's. (Stupid but true)
2) Using a wire guage check the size and continuity of the gas port. The size should be between 0.87-.093 depending on manufacturer.
A "continuity check" seems redundant but I've run across several barrels that had burrs in the gas port holes... thus blocking the flow.
This IS rare as hell but does happen. Soooo.. better to be sure it's not the issue.
3) Check to make sure the gas tube was installed right side up! I shit you not ! I've had several NIB rifles pass through my hands that had their gas tubes installed upside down.
If your still short stroking after checking and correcting the previous then either you are using some seriously wimpy ammunition OR your buffer/spring combination is too heavy/strong.
No fast fix for this issue. Grab several different rifle/carbine springs and buffers of varying weights and go to the range. (or the bang box in my case)
In my experience these have been the most common ways to fix the issue you're experiencing.
As always, YMMV
Regards,
TJ
This makes no sense. A rifle shouldn't be using anything other than a rifle spring and buffer or an A5 system if you want telescoping stocks.
Dude! I've see retards on another AR website that openly admited to running carbine buffers in a rifle RE.
The idiots got pissy with me when I attempted to explain how farked up that idea was. :rolleyes:
I have a BCM 18" barrel with rifle length gas system. I am using a carbine receiver extension and spring with an H3 buffer. It runs absolutely fine with .223 commercial ammunition.
It will also run with a carbine, H or H2 buff it is just a little smoother with the H3.
My rule of thumb for handguns and rifles is that; if they don't run perfectly with standard springs, then the firearm needs to be fixed.
Cameron
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