LVSteve
Member
His measurements showed that all was well with the guns tested. I am not convinced that ALL eventualities were covered, but I think he showed that it is very unlikely that 5.56 will cause problems in most .223 marked guns.
Some AR-15 questions for ya.
- Thread starter PALADIN85020
- Start date
His measurements showed that all was well with the guns tested. I am not convinced that ALL eventualities were covered, but I think he showed that it is very unlikely that 5.56 will cause problems in most .223 marked guns.
mkk41
US Veteran
Best current production mags IMO;
metal = Brownell's
plastic = MagPul P-mags.
metal = Brownell's
plastic = MagPul P-mags.
OP
I have a Match HBAR AR-15 put together by Colt in 1985. The chamber is extremely tight. If I chamber a 5.56mm in its .223 chamber, it sticks so tight I cannot extract it by normal means. In the past, I just fired the gun to eject the case; no damage ensued. Today, I'm careful to shoot only .223 in it. However the point is that even with this extreme mismatch, things held together.
I have an M4 clone with the upper made by a private manufacturer in 1999. The barrel is not marked for either cartridge. I've fired 5.56 and .223 in it interchangeably and extensively. No problems once I got the proper port diameter issue worked out with the manufacturer. It chews 'em all up and spits 'em out.
John
I have a Ruger 77 MK2 standard sporter with 22" barrel marked .223.
It has not been fired a great deal since I bought it but most of the
rounds fired have been 5.56mm. No problems so far.
It has not been fired a great deal since I bought it but most of the
rounds fired have been 5.56mm. No problems so far.
#1- No
#2 Polymer (Pmag) Steel (E-Lander)
Is this testable?
#2 Polymer (Pmag) Steel (E-Lander)
Is this testable?
mkk41
US Veteran
Chamber dimensions are not the problem. It's the amount of leade , where the ogive of the bullet engages the rifling. Most commercial .223 Rem varmint rifles meant for lighter bullets and have a very short leade. Most heavier and many military bullets need a longer leade. Sometimes also (but incorrectly) called 'freebore'.
The problem occurs when a bullet engages the rifling as the round is chambered , and it gets pushed back into the case , encroaching on the powder charge , compressing it slightly , spiking pressure.
An easy check is to 'smoke' the bullet with a candle or simply blackening it with a magic marker. Chamber and extract the round. If the bullet shows any contact with the rifling (just forward of case mouth) , don't shoot those rounds.
OP
I have no doubt that you're right on that. Still, I believe the chambers on the match HBARs were cut to minimum specs so there would be not be a whole lot of slop in the chambering. Regardless, the net affect is that it's "tight" with 5.56, but still will fire with no apparent problems. I'm pretty sure the proof rounds they run through these guns at the factory far exceed any overpressure that would occur with the 5.56. I suspect, as the tests cited here have shown, the issue is a mite overblown. Just for the record, I don't recommend shooting 5.56 in a .223 chamber, but it doesn't worry me personally a whole lot.
John
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jaykellogg
Absent Comrade
If the bullet engages the leade and you try and eject the unfired cartridge the bullet can stay stuck. This really causes problems if you don't notice it.
mkk41
US Veteran
Haven't read all prior responses , but I do believe the popular .223 Wylde chamber spec uses the tighter .223 Rem for the chamber , but the longer leade of the 5.56 NATO , and will take long 77-80gr bullets.
I also think there may be something about the neck diameter. Military brass tends to be thicker there. If ya gotta force that bolt home on mil-spec rounds, ya might be squeezing the case neck to the bullet.
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LouisianaJoe
Member
I have a Thompson Contender Super 14 with a .223 barrel and a 1:12 twist. I shot a couple of 55gr 5.56 NATO in it and the primers backed out enough to make it difficult to open it. I did not do that again. It likes 40gr better anyway.
I have had good luck with Magpul. I use 20 rd mags the most because they work better with a bipod.
I have had good luck with Magpul. I use 20 rd mags the most because they work better with a bipod.
Malpasowildlifer
Member
I use 30 round Magpuls at work and they are great.
Watch for the difference for pressure issues.
A Colt is all you need....I'd only get something else/build for a precision AR
Watch for the difference for pressure issues.
A Colt is all you need....I'd only get something else/build for a precision AR
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