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Build Thread AR pistol question

E4mafia

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Not sure which section to throw this in (Sorry mods)


My questioning is this.

I plan to buy a set up from PSA using a SB braced stock and a upper of at least 8.5" barrel.

I hear that going under 10" makes 5.56 suffer but I am honestly not looking for long range engagement but more of a bugout build that'll at least hit consistently at 150 meters between irons/optic.

What I am asking is basically how reliable is a 8.5" barrel and a 5.56 generally going to perform? I know they are louder from what I hear but I am wondering if its that drastic of a drop off for the platform considering I plan to keep it mostly as close to semi intermediate build anyway intentionally.

Example of my rough build idea:
upper: PSA 8.5" Pistol-length 5.56 NATO 1/7 Nitride 7" Lightweight M-Lok Upper w/o BCG or CH - 516447044
lower: PSA AR15 Complete MOE EPT SBA3 Lower - 5165448150
 
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E4mafia

E4mafia

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Any suggestions on a A5 buffer?

Whats wrong with the stock one? Will it affect performance or operation if i do not?

Thanks
 
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A5 is basically a Rifle spring and longer buffer in a CAR tube, with the weights springloaded for less bounce. Tons of technical data over at M4Carbine.net, they're a HUGE reliability improvement on shorties. BCM usually ships their kits with an A5H0 buffer, Vltor themselves usually use A5H2. In your case, this is purely pulling a guess out of my arse since I'm not an expert, were I building an 8.5" I would probably go no lighter than A5H3 or A5H4.

Alternatively, you might look at Geissele's Super 42 system--it's Carbine length spring, but braided wire similar to the German MG42. Definitely, you should look into joining M4C--while our tech guru Iraqgunz just got called up to run St. Peter's armory upstairs, you won't find a better body of technical experts on the AR platform, particularly the M4 and shorter variants, anywhere.
 
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E4mafia

E4mafia

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Ok so you mostly mean the buffer and the spring set then.

I'll see if I can dig one up on PSA. Thanks for the info!

A5 is basically a Rifle spring and longer buffer in a CAR tube, with the weights springloaded for less bounce. Tons of technical data over at M4Carbine.net, they're a HUGE reliability improvement on shorties. BCM usually ships their kits with an A5H0 buffer, Vltor themselves usually use A5H2. In your case, this is purely pulling a guess out of my arse since I'm not an expert, were I building an 8.5" I would probably go no lighter than A5H3 or A5H4.

Alternatively, you might look at Geissele's Super 42 system--it's Carbine length spring, but braided wire similar to the German MG42. Definitely, you should look into joining M4C--while our tech guru Iraqgunz just got called up to run St. Peter's armory upstairs, you won't find a better body of technical experts on the AR platform, particularly the M4 and shorter variants, anywhere.

This the one you are referring to?
 
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Um, one thing I didn't get out: A5 buffer and tube are 3/4" longer--it basically combines Rifle length with Carbine telestock capability. Original intent was for the aborted M16A5 program; instead they just combined CAR telestocks with the H6 superheavy buffer as a "Short Operator Retrofit" for the M16A4.

PSA doesn't sell A5 systems last I knew... and whatever you do, DON'T mention Palmetto over at M4C. :) Fallback, you might check OpticsPlanet.

But yeah, that's the Super 42 system--Arms Unlimited out of Vegas has an off-brand clone that's more budget friendly.
 
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E4mafia

E4mafia

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Ok I think i'll go with that super 42 for my build then.

Any suggestion on a BCG? I had a nickle boron one but it just sold out. Or would any basic BCG do the trick in a shorty?
 
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I have a 7.5" AR pistol. Only time I had an issue was with a lower that had a PDQ. The PDQ was a ambi bolt hold open but it was too heavy and I had issues with the BCG not locking back after last round. I replaced the bolt hold open with a regular ping pong paddle one and that solved my issue.

I have a better lower for my pistol now and I haven't had any issues with the new setup. I've shot wolf steel, brass .223 and 5.56 out of my AR pistol without any malfunctions.

I am running a Colt H3 buffer and I'm ejecting my casings at about the 3 o'clock position.

I have a stag bolt carrier and a sharps reliabolt (bolt) .

My previous AR pistol was a 10.5" and I ran a Spikes tactical T-2 buffer. Can't recall the ejection pattern but it ran just fine.
 
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Go 11.5”.... both of these have standard carbine guts (with KNS pin retainers) and haven’t missed a beat a single time. ;)

View attachment 623174
IMO anything under 11.5" is too short for 5.56 and is .300 BO territory. My personal fav is a BCM 12.5" KINO, which has carbine gas system with a standard sight at the mid-length position (think mini dissipator), that gives you adequate 5.56 performance, longer sight radius, more real estate to grab hold of and a greater dwell time, while still short enough add a suppressor and not be cumbersome.

That said, if I going to build myself a dedicated suppressed pistol or SBR I'd build it around a SIONICS 11.5" reduced gas port barrel.
 
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My two 11.5" are plenty within my accuracy expectations out to 400+
Recently I got the urge and built a 7.5", based on this barrel.
 
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I Agree with above post about 300 BO territory/better fit for that barrel length. Kinda gets away from the strength of that round when using shorter barrel lengths imo.
ECFA0402-F2FD-40DF-BEB6-0329511B409B.png
 

nwslopoke

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Is the real issue not reliability but velocity? Under a 10.5 inch barrel the 5.56 doesn't reach enough speed to fragment as designed. My theory. Easily debunked.

I think below that for 5.56 there are other rounds that performs better like 300 BO.
 
Firing 556 of a 7.5" barrel will penetrate the door of a 60's Chevy truck, and break the glass @ 300+ yds.
Not that I'd ever make the choice to carry one for life dependence at that distance, but @ 100/200/300, aim for the adams apple ;)
 

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