AR15 Shorty

[Cliff R]

I was using Magpul 20 and 30 round magazines and had one 40 rounder but it hated all of them.  Didn't have anything else with me to test..

I moved the same magazines over to the other AR-15 and ran over 140 rounds thru it flawlessly.

Even moved the buffer spring and follower from one weapon to another, ALL the issues stayed with the short barreled upper.  It has a MAJOR issue of some sort, but I didn't go into it to check the gas port for size or alignment, etc.  Did look at protrusion of the gas tube and it's in equally as far as the other upper so didn't figure that was the issue.  I didn't move the bolt from one to another because I wanted to keep their upper as-is and not try to troubleshoot it for them.  If it's a bolt issue of some sort they can figure that out and replace it under warranty.

Had ZERO luck getting in touch with PSA they aren't answering the phones and say to send an email instead.  I sent one yesterday morning and another one mid afternoon and still no response from them.  I'll send a few more today until someone answers so I can get this thing shipped back and either repaired or replaced.

Minor chit in the big scheme of things I have PLENTY of other AR's to take to the range........

Edited May 27, 2020 by Cliff R

[Albroswift]

Getting my shorty out finally, heading to a "Picnic / Camping Firearms Allowed" invitational over east of the mountains. Hopefully I don't encounter @Cliff R type issues. 

 

Taking pistols, rifles and carbines from black powder to AR308. 2 new builds that haven't been tested plus the @aadavis94 bolt with oversized ejector in a Toolcraft BC see  if that runs in the 308/ 12.5 Sig barrel setup. 

[Cliff R]

So far have heard NOTHING back from PSA.  I suppose the COVID thing has them working a little short handed, at least in the Customer Service side of things.......

[Albroswift]

Ok, shot the shorty, ran out a couple mags except for the very first round behaved flawlessly with 62gr suprising velocity,  2400 or so expected lot less on a 7.5 in barrel 

 

[Albroswift]

Went to the rifle range to sight in the shorty, got it hitting square at 100 yards, shooting 62gr green tips, good group, 100% function. then tried the 40 gr blue tips, good group and function, then tried 2 different brands of 55 gr, mil 556 and civilian 223, neither one worked worth a $hit. Maybe dirty? no, went back to the green tips no problem. The 55's are acting like a failure to extract, but get lock back and no issues chambering one with empty mag. Try some different mags and a lighter recoil spring next time. 

[unforgiven]

On 5/28/2020 at 3:43 PM, Cliff R said:

So far have heard NOTHING back from PSA.  I suppose the COVID thing has them working a little short handed, at least in the Customer Service side of things.......

They are hard to contact on a good day

[98Z5V]

16 hours ago, Albroswift said:

Went to the rifle range to sight in the shorty, got it hitting square at 100 yards, shooting 62gr green tips, good group, 100% function. then tried the 40 gr blue tips, good group and function, then tried 2 different brands of 55 gr, mil 556 and civilian 223, neither one worked worth a $hit. Maybe dirty? no, went back to the green tips no problem. The 55's are acting like a failure to extract, but get lock back and no issues chambering one with empty mag. Try some different mags and a lighter recoil spring next time. 

What's your barrel twist, brother?  Those 55s are running north of 3100fps, some 3300fps - through a typical AR15, 20"er.  That's their design.  Those M855s are designed to run 3100fps through the M16A2.  You're rocking 2400fps with the M855 and a 7.5" barrel.  I ran the math on the projectile a LONG time ago.  The 5.56 projectile is designed to frag when it goes into something, that's the only reason it's effective.  With a 62gr M855, you need 1700fps ON TARGET for that thing to frag.  Same on the 55s.  That give you about 175 yards of realistic distance with a short AR.  Otherwise, it's not fragging and just leaving holes, like an expensive ice pick.

So, reason I asked about your twist rate - those 55gr loads aren't in a barrel long enough to "settle down" - and if it's a 1:7" twist, those tiny little fast bastards are coming out of the end of that barrel, and just going haywire.  Surprised those 40s did well - they have to be screaming.

[Cliff R]

Update.

PSA is back in business and the upper goes back to them today.  Stay tuned.....I'll update the thread when the upper gets back and we get to the range again......

[Albroswift]

On 6/8/2020 at 9:07 PM, 98Z5V said:

What's your barrel twist, brother?  Those 55s are running north of 3100fps, some 3300fps - through a typical AR15, 20"er.  That's their design.  Those M855s are designed to run 3100fps through the M16A2.  You're rocking 2400fps with the M855 and a 7.5" barrel.  I ran the math on the projectile a LONG time ago.  The 5.56 projectile is designed to frag when it goes into something, that's the only reason it's effective.  With a 62gr M855, you need 1700fps ON TARGET for that thing to frag.  Same on the 55s.  That give you about 175 yards of realistic distance with a short AR.  Otherwise, it's not fragging and just leaving holes, like an expensive ice pick.

So, reason I asked about your twist rate - those 55gr loads aren't in a barrel long enough to "settle down" - and if it's a 1:7" twist, those tiny little fast bastards are coming out of the end of that barrel, and just going haywire.  Surprised those 40s did well - they have to be screaming.

Yes it's a 1:7, got great groups out of both the 40's and 62's. Didn't break the chrono out, sighting in  and screwing around, but chrono'd a few 62's the other day still going over 2200 at 69 yards when the radar lost track.

Anyway, back pack gun, not worried about long range performance. One other thing, got a couple of double fires with both the 62's and the 40's, slower then a slam fire I think it was trigger bounce. I'll try a couple things and maybe get to the range this weekend. See if I can get a track out to 100 yards. 

[98Z5V]

[392heminut]

Ya know, some guys over on the 300blk forum were saying that ukulele cases make great clandestine AR pistol cases.

[unforgiven]

Mini Desperado guitar case.

[Albroswift]

Swapped out the Tailhook/ LAW folder with the Deadfoot 2.5 brace. 

[Albroswift]

Got it to the range, damn thing works! Cycled and LRBHO on everything from 40 gr to 62 gr.  Shot without using the brace, off hand, about a paper plate sized group at 50 yards. (didn't want to start with my face anywhere near the goofy thing) When the trust level went up, used the brace and put my face a little closer to the charging handle the group tightened up quite a bit. The bolt headspace was tight in the Anderson barrel, still in spec but on the tight side, enough that a couple of my handloads were sticky when manually extracting with the charging handle. Probably swap the bolt with the one out of the old BCG.

EDIT: Nope, both bolts headspace the same, just a couple of fat handloads. 

Edited July 2, 2021 by Albroswift

[unforgiven]

Great job brother 

[shooterrex]

Nice