User Panel
Posted: 2/2/2016 12:52:03 AM EDT
I have one of these:
and I cant get it to cycle reliably at all. I am on a standard PSA lower with a regular build kit and I'm using a random charging handle and a new BCM bolt carrier backed by a standard carbine H2 buffer and carbine buffer tube shooting XM193. Any ideas where to start? |
|
[#1]
Usually you want a heavier buffer the shorter the gas system is. I recommend trying either a carbine or H buffer to see if that rectifies the situation. Also ensure you are lubing the bolt carrier group. Lastly, even if it is a new BCG check the gas rings on the bolt to ensure they are aligned properly and/or free of damage. Pending those issues my money is on issues with the gas block or gas tube. Hope this helps!
ATW! -Fox |
|
[#2]
I found a heavy buffer, Im going to try that next. I assumed PSA test fired this upper they built and would've shown any issues with the gas block alignment but who knows. The gas rings are on OK in the BCG and its lubed up pretty decently.
|
|
[#3]
Quoted:
I found a heavy buffer, Im going to try that next. I assumed PSA test fired this upper they built and would've shown any issues with the gas block alignment but who knows. The gas rings are on OK in the BCG and its lubed up pretty decently. View Quote Since you didn't explain the nature of the malfing, I don't see how anyone could possibly suggest a remedy. For example, if it's short stroking, not locking back on shooting a single round, the last thing you would want is a heavier buffer. - OS |
|
[#4]
Did you check your gas block? I just put together a pistol with their 8.5" 300 blk. Gas block screws weren't tight at all. I dimpled the barrel and staked them. Not saying that's the source of your problem, but worth a check.
|
|
[#5]
Quoted:
Since you didn't explain the nature of the malfing, I don't see how anyone could possibly suggest a remedy. For example, if it's short stroking, not locking back on shooting a single round, the last thing you would want is a heavier buffer. - OS View Quote View All Quotes View All Quotes Quoted:
Quoted:
I found a heavy buffer, Im going to try that next. I assumed PSA test fired this upper they built and would've shown any issues with the gas block alignment but who knows. The gas rings are on OK in the BCG and its lubed up pretty decently. Since you didn't explain the nature of the malfing, I don't see how anyone could possibly suggest a remedy. For example, if it's short stroking, not locking back on shooting a single round, the last thing you would want is a heavier buffer. - OS Yes more details would help. Also, if youjust throw an H2 buffer in because it sounds like a good idea,,,,,,you're doing it wrong. You should start with a standard weight then move heavier if necessary. |
|
[#6]
PSA has a lot of inadequete quality parts and terrible quality control on the things they build. These are the corners that get cut to bring you lower cost products.
The low quality parts could be causing extraction issues, or the combination could be under or over gassed. This could be the heavy buffer and heavier (full auto) bcg, a misalligned gas block, etc. The gas rings shouldn't be causing this. Not in a new BCM bcg. Allignment of the rings is supposedly and likely negligible. The bolt should hold up the weight of carrier if extended and placed upright on a table. Between a new BCG and an H2 buffer, that might be why. Check your ejection pattern. If you're throwbrass really far rearward, it's undergassed and you should try a stanard carbine buffer. |
|
[#7]
OK, heres what it does consistently with a stock buffer.
Charge weapon, shoot, bolt comes back and picks up new round, everything looks good on the outside, trigger does not move back (just a tiny bit of movement), hit forward assist, same trigger feel , charge weapon, clean round ejects, new one goes in and gun will shoot again one round, repeat (so gun does not go into battery correctly with H2 buffer: instant double feed on the shoot. So H2 buffer coming out of the pistol lower. Next trial, Im going to put the 8.5 (5.56) PSA upper on my SBR lower and swap the regular buffer in that gun also (it usually carries the h2 because its a 300blk 8.2" rig) I agree, the BCG is good to go, the thing is lubed ok. Im going to rule out the lower as any cause |
|
[#8]
Your trigger is not resetting. Sounds like a problem within the lower, not due to the upper.
Quoted:
Usually you want a heavier buffer the shorter the gas system is. I recommend trying either a carbine or H buffer to see if that rectifies the situation. Also ensure you are lubing the bolt carrier group. Lastly, even if it is a new BCG check the gas rings on the bolt to ensure they are aligned properly and/or free of damage. Pending those issues my money is on issues with the gas block or gas tube. Hope this helps! ATW! -Fox View Quote Not with a barrel that short. There's not much back pressure (which is why the Noveske KX3 came to be). Go with a standard spring, carbine buffer, and M16 profile carrier. |
|
[#9]
Yeah, I'll also try a known good 16" upper on this pistol lower to prove that scenario.
Nothing on the pistol lower is proven either so I'm thinking the same thing. |
|
[#10]
You didn't mention simplest test. Load single round in mag, charge, shoot. Does it lock back?
If not, almost certainly undergassed for one of several reasons. - OS |
|
[#12]
Quoted:
Yeah, I'll also try a known good 16" upper on this pistol lower to prove that scenario. Nothing on the pistol lower is proven either so I'm thinking the same thing. View Quote If it is indeed extracting/ejecting the fired case then chambering a new round, then I would bet your trigger has an issue. Did you install your disconnector spring properly? |
|
[#13]
I think this right here is the issue:
http://www.ar15.com/forums/t_3_4/428705_.html I should edit the title to avoid misleading issue as PSA faulty product |
|
[#14]
Quoted: If it is indeed extracting/ejecting the fired case then chambering a new round, then I would bet your trigger has an issue. Did you install your disconnector spring properly? View Quote This was indeed the issue. Fires great now although loud as hell. Makes a great nighttime toy as fireballs exit 2' out the front |
|
[#15]
Quoted:
This was indeed the issue. Fires great now although loud as hell. Makes a great nighttime toy as fireballs exit 2' out the front View Quote View All Quotes View All Quotes Quoted:
Quoted:
If it is indeed extracting/ejecting the fired case then chambering a new round, then I would bet your trigger has an issue. Did you install your disconnector spring properly? This was indeed the issue. Fires great now although loud as hell. Makes a great nighttime toy as fireballs exit 2' out the front How is this 8.5" upper holding up for you Armamnt? Are you seeing decent accuracy? I just ordered one yesterday on PSA daily deal. Hoping it to round out my pistol upper collection of 10.5" and 12.5" |
|
[#16]
So, I got my 8.5" PSA upper that the OP is referring to.
First impressions, it doesn't shoot very good. Everything cycles fine, but accuracy is terrible. I put about 140 rds through it yesterday. I tried Wolf Gold, PMC Bronze, LC 855 and some known good reloads with 55gr. Finished off the day with wolf steel to see if it would cycle. Best group was about 4" at 50 yards. For accuracy testing I had attached a bipod and 1-6x scope. Later in the day removed the scope and had the exact same results with irons. So that pretty much leaves the barrel. I will take it out again and put another hundred or 2 rounds through it and see if it settles in. Initial impressions are crap. For a data point. My recent 12.5" and 10.5" builds achieved 1/2" groups and no worse than 1" using the same process and ammo at 50 yds. Before my next trip I will remove the handguard and barrel and make sure it is properly installed/torqued etc. If there is no change after that, probably replace the barrel with a faxon or something. |
|
[#17]
Quoted:
PSA has a lot of inadequete quality parts and terrible quality control on the things they build. These are the corners that get cut to bring you lower cost products. The low quality parts could be causing extraction issues, or the combination could be under or over gassed. This could be the heavy buffer and heavier (full auto) bcg, a misalligned gas block, etc. The gas rings shouldn't be causing this. Not in a new BCM bcg. Allignment of the rings is supposedly and likely negligible. The bolt should hold up the weight of carrier if extended and placed upright on a table. Between a new BCG and an H2 buffer, that might be why. Check your ejection pattern. If you're throwbrass really far rearward, it's undergassed and you should try a stanard carbine buffer. View Quote |
|
[#18]
99% of the time with AR Pistols not cycling its a gas block issue, not tightened down properly and has walked slightly. I would check that first.
We specialize in the AR Pistol and we sell a ton of them. If you guys have any questions or need parts feel free to email me anytime! |
|
[#19]
New member here and I may be stirring a pile of bovine excrement, but what I can see is PSA has great reviews. Must be that MN water. ;)
|
|
[#20]
With a short barrel, you don't have much barrel past the gas port, so you have reduced dwell time.
With that setup I would start with a CAR buffer, maybe try an H1if it will function. An H2 is probably too heavy. |
|
[#21]
Quoted:
So, I got my 8.5" PSA upper that the OP is referring to. First impressions, it doesn't shoot very good. Everything cycles fine, but accuracy is terrible. I put about 140 rds through it yesterday. I tried Wolf Gold, PMC Bronze, LC 855 and some known good reloads with 55gr. Finished off the day with wolf steel to see if it would cycle. Best group was about 4" at 50 yards. For accuracy testing I had attached a bipod and 1-6x scope. Later in the day removed the scope and had the exact same results with irons. So that pretty much leaves the barrel. I will take it out again and put another hundred or 2 rounds through it and see if it settles in. Initial impressions are crap. For a data point. My recent 12.5" and 10.5" builds achieved 1/2" groups and no worse than 1" using the same process and ammo at 50 yds. Before my next trip I will remove the handguard and barrel and make sure it is properly installed/torqued etc. If there is no change after that, probably replace the barrel with a faxon or something. View Quote Any update on this problem? Inquiring minds would like to know. |
|
[#22]
Quoted:
Any update on this problem? Inquiring minds would like to know. View Quote View All Quotes View All Quotes Quoted:
Quoted:
So, I got my 8.5" PSA upper that the OP is referring to. First impressions, it doesn't shoot very good. Everything cycles fine, but accuracy is terrible. I put about 140 rds through it yesterday. I tried Wolf Gold, PMC Bronze, LC 855 and some known good reloads with 55gr. Finished off the day with wolf steel to see if it would cycle. Best group was about 4" at 50 yards. For accuracy testing I had attached a bipod and 1-6x scope. Later in the day removed the scope and had the exact same results with irons. So that pretty much leaves the barrel. I will take it out again and put another hundred or 2 rounds through it and see if it settles in. Initial impressions are crap. For a data point. My recent 12.5" and 10.5" builds achieved 1/2" groups and no worse than 1" using the same process and ammo at 50 yds. Before my next trip I will remove the handguard and barrel and make sure it is properly installed/torqued etc. If there is no change after that, probably replace the barrel with a faxon or something. Any update on this problem? Inquiring minds would like to know. I took it out and put another 100 rounds through it. Groups started to settle down a little, but didn't get much better than about 2.5"- 3" @ 50yds. Before next trip I will pull the barrel and reassemble and try 1 more time before replacing the barrel. |
|
[#23]
I have the same exact upper and my gas block is super crooked.
Like almost touching the inside of the handguard on one side, but a good 1/4" of space on the other side. Haven't shot it yet. Trying to decide if I should try to fix it first or just leave it alone. |
|
[#24]
I built one with the same upper. My whole build is PSA parts. (Except for Anderson Pistol Buffer Tube Kit PSA was out)The parts they sell have good reviews and this upper has an 18 5 star review. After I put the lower together and put on the upper I ran three shots to see if it functioned. Worked fine. I didn't have a bolt carrier group or charging handle yet so borrowed one out of a rifle. When I get those parts I will start shooting it to break it in. I see some one commented about their gas block being crooked. Mine is perfectly straight. I am satisfied with the quality of their parts.
|
|
[#26]
Quoted:
Quoted:
PSA has a lot of inadequete quality parts and terrible quality control on the things they build. These are the corners that get cut to bring you lower cost products. The low quality parts could be causing extraction issues, or the combination could be under or over gassed. This could be the heavy buffer and heavier (full auto) bcg, a misalligned gas block, etc. The gas rings shouldn't be causing this. Not in a new BCM bcg. Allignment of the rings is supposedly and likely negligible. The bolt should hold up the weight of carrier if extended and placed upright on a table. Between a new BCG and an H2 buffer, that might be why. Check your ejection pattern. If you're throwbrass really far rearward, it's undergassed and you should try a stanard carbine buffer. Ya... Numerous people just in this thread with this same item complaining about probable quality issues. yourself. |
|
[#27]
Quoted:
I took it out and put another 100 rounds through it. Groups started to settle down a little, but didn't get much better than about 2.5"- 3" @ 50yds. Before next trip I will pull the barrel and reassemble and try 1 more time before replacing the barrel. View Quote View All Quotes View All Quotes Quoted:
Quoted:
Quoted:
So, I got my 8.5" PSA upper that the OP is referring to. First impressions, it doesn't shoot very good. Everything cycles fine, but accuracy is terrible. I put about 140 rds through it yesterday. I tried Wolf Gold, PMC Bronze, LC 855 and some known good reloads with 55gr. Finished off the day with wolf steel to see if it would cycle. Best group was about 4" at 50 yards. For accuracy testing I had attached a bipod and 1-6x scope. Later in the day removed the scope and had the exact same results with irons. So that pretty much leaves the barrel. I will take it out again and put another hundred or 2 rounds through it and see if it settles in. Initial impressions are crap. For a data point. My recent 12.5" and 10.5" builds achieved 1/2" groups and no worse than 1" using the same process and ammo at 50 yds. Before my next trip I will remove the handguard and barrel and make sure it is properly installed/torqued etc. If there is no change after that, probably replace the barrel with a faxon or something. Any update on this problem? Inquiring minds would like to know. I took it out and put another 100 rounds through it. Groups started to settle down a little, but didn't get much better than about 2.5"- 3" @ 50yds. Before next trip I will pull the barrel and reassemble and try 1 more time before replacing the barrel. Something I think was affecting me once... had an SPR type build that was grouping like crap with glass on it. Like 2" at 25yd. It was also kicking harder than any AR or mil M16 series I'd ever fired. Brass was ejecting at about 1 o'clock. Switched out the gas block with a well throttled adjustable one and now it's a very accurate gun. Limited just about only by ammo type now. Wilson Combat stainless barrel. So I'dcheck your ejection pattern. |
|
[#28]
I ordered one of the uppers in question. It will be here in a few days along with a PSA full auto BCG.
The lower it will go on has been tested with a couple different pistol uppers and it functions perfectly. So, when I get it ill report any noticeable issues and likewise after I shoot it. |
|
[#29]
|
|
[#31]
I have one of these uppers and function tested it with 30 rounds. It ran flawlessly. The lower it was on is an Anderson lower that I put together....... correctly.
|
|
Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!
You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.
AR15.COM is the world's largest firearm community and is a gathering place for firearm enthusiasts of all types.
From hunters and military members, to competition shooters and general firearm enthusiasts, we welcome anyone who values and respects the way of the firearm.
Subscribe to our monthly Newsletter to receive firearm news, product discounts from your favorite Industry Partners, and more.
Copyright © 1996-2024 AR15.COM LLC. All Rights Reserved.
Any use of this content without express written consent is prohibited.
AR15.Com reserves the right to overwrite or replace any affiliate, commercial, or monetizable links, posted by users, with our own.