CASEYPM Posted September 3, 2021 Report Share Posted September 3, 2021 I just took my PSA PA-10 1st gen out today with a new UTG A2 stock and 9/10 it would eject, but 10/10 would not feed. It has a full size buffer that is 5.4 oz and the spring is much stiffer than the stock spring. I may be an idiot for trying this, but I used the new buffer with the old carbine spring and it double fed every time and the pin would punch the primer. I thought of two solutions for this and want to see what y'all think. 1. Cut a wooden dowel the same diameter of the inside of the receiver extension tube to make the inside length the same length as the carbine, and use the original buffer and spring. 2. Start cutting off coils of the new spring using new buffer until it cycles right. 3. Buy a new spring that y'all think would be right for it. Any new insight would be much appreciated. Quote Link to comment Share on other sites More sharing options...
Armed Eye Doc Posted September 3, 2021 Report Share Posted September 3, 2021 Where did you get the new receiver extension? What is the length of the buffer? Quote Link to comment Share on other sites More sharing options...
CASEYPM Posted September 3, 2021 Author Report Share Posted September 3, 2021 25 minutes ago, Armed Eye Doc said: Where did you get the new receiver extension? What is the length of the buffer? AR-15discounts.com It is 5-7/16 long and weighs 5.3 oz. Quote Link to comment Share on other sites More sharing options...
Armed Eye Doc Posted September 3, 2021 Report Share Posted September 3, 2021 (edited) The weight is right but it should be 5.2 inches long. Can you post a picture of the measurement of the buffer to be sure? What is the internal depth of the receiver extension? It should be 9.625 inches. Edited September 3, 2021 by Armed Eye Doc Quote Link to comment Share on other sites More sharing options...
98Z5V Posted September 3, 2021 Report Share Posted September 3, 2021 5 7/16" for a buffer is way wrong. AR15 rifle buffers are 5.900" long. .308AR rifle buffers are 5.200" long. Rock River Arms LAR-8 rifle buffers are different, and don't count in that. 5 7/16" - 5.4375" doesn't match up to anything known. Either the measurement is off - or that buffer length is way off. Next, it's a PSA PA-10, so the gas tube probably isn't the right length, from the beginning, and the gas port in the barrel is probably too small. It might have functioned, before, but that's because PSA sends those guns out with a cobbled up bullshiit carbine recoil system, that barely covers for the other gas system mistakes that they make on those guns. Don't take offense to those comments - it's been documented time and time again here. It's just "history" with PSA. You might have alot of work to do to that rifle to make it run. Quote Link to comment Share on other sites More sharing options...
Cliff R Posted September 3, 2021 Report Share Posted September 3, 2021 I've converted all of my 308-AR's to A2 stocks, but never used one from UTG. I sourced out Mil-Spec A2 stocks and tubes instead. I sourced DPMS springs and buffers for them. The part numbers are below. I did all this WAY before finding this site and for 3 different manufacturers of 308-AR's. Two were PSA, one from Veriforce Tactical and two from Alexandria Pro-Fab. Right, wrong or otherwise all of them run flawlessly. Here are the part numbers: PMS LR-308 Buffer Rifle 308-BS-11 DPMS LR-308 Buffer Spring 308-BS-10B Quote Link to comment Share on other sites More sharing options...
edgecrusher Posted September 3, 2021 Report Share Posted September 3, 2021 I would change your buffer and spring. Then get an idea out if your gas timing is correct. Then check your gas port. In that order Quote Link to comment Share on other sites More sharing options...
CASEYPM Posted September 3, 2021 Author Report Share Posted September 3, 2021 14 hours ago, 98Z5V said: 5 7/16" for a buffer is way wrong. AR15 rifle buffers are 5.900" long. .308AR rifle buffers are 5.200" long. Rock River Arms LAR-8 rifle buffers are different, and don't count in that. 5 7/16" - 5.4375" doesn't match up to anything known. Either the measurement is off - or that buffer length is way off. Next, it's a PSA PA-10, so the gas tube probably isn't the right length, from the beginning, and the gas port in the barrel is probably too small. It might have functioned, before, but that's because PSA sends those guns out with a cobbled up bullshiit carbine recoil system, that barely covers for the other gas system mistakes that they make on those guns. Don't take offense to those comments - it's been documented time and time again here. It's just "history" with PSA. You might have alot of work to do to that rifle to make it run. Measured it twice and got that both times. As for the gas tube, I'm using an armalite AR-10 carbine length tube which is about 3/8 longer than an AR-15 mid length tube. (Sounds backwards, but that's AR-10 specs for them) I had short cycling in the beginning with the PSA tube until I found the right length of gas tube. No offense taken. I decided on PSA years ago because of the price and made it a franken gun from multiple suppliers Quote Link to comment Share on other sites More sharing options...
CASEYPM Posted September 3, 2021 Author Report Share Posted September 3, 2021 11 hours ago, Cliff R said: I've converted all of my 308-AR's to A2 stocks, but never used one from UTG. I sourced out Mil-Spec A2 stocks and tubes instead. I sourced DPMS springs and buffers for them. The part numbers are below. I did all this WAY before finding this site and for 3 different manufacturers of 308-AR's. Two were PSA, one from Veriforce Tactical and two from Alexandria Pro-Fab. Right, wrong or otherwise all of them run flawlessly. Here are the part numbers: PMS LR-308 Buffer Rifle 308-BS-11 DPMS LR-308 Buffer Spring 308-BS-10B Thank you, I will probably end up purchasing one. Quote Link to comment Share on other sites More sharing options...
CASEYPM Posted September 3, 2021 Author Report Share Posted September 3, 2021 8 hours ago, edgecrusher said: I would change your buffer and spring. Then get an idea out if your gas timing is correct. Then check your gas port. In that order Timing and tube length are correct. If anything, I always thought the gun was over gassed by the amount of recoil and how far it eqects shells compared to other AR308s. Definitely changing buffer and spring. Quote Link to comment Share on other sites More sharing options...
billymagg Posted October 26, 2021 Report Share Posted October 26, 2021 On 9/3/2021 at 3:39 PM, CASEYPM said: Timing and tube length are correct. If anything, I always thought the gun was over gassed by the amount of recoil and how far it eqects shells compared to other AR308s. Definitely changing buffer and spring. So did you change the buffer and spring?? and if so, what did you replace it with?? so your gas tube is coming all the way back to the middle of the cam pin cutout in the upper receiver??? pictures of all that please if possible.. if you were 10 out of 10 for not feeding, it sounds like you were short stroking,, a buffer that was too long being out of spec would cause that.. 98Z gave you some great advice, did you measure the gas port bore?? report that bore diameter back please.. One Armed Eye Doc asked you about the length and source of rear receiver extension, should be 9.625 inches These guys KNOW, they are NOT guessing or taking a stab in the dark,, if you follow their very specific advice and give them GOOD information, they will get your rifle running reliably... or you've got it all figured out?? and we will never hear from you again?? not likely, but even a blind hog finds an acorn once in a while... Quote Link to comment Share on other sites More sharing options...
billymagg Posted October 26, 2021 Report Share Posted October 26, 2021 On 9/2/2021 at 10:23 PM, Armed Eye Doc said: The weight is right but it should be 5.2 inches long. Can you post a picture of the measurement of the buffer to be sure? What is the internal depth of the receiver extension? It should be 9.625 inches. The receiver extension is supposed to come with the kit Doc, but I did find one review, where the purchaser stated that it came with an AR-15 Buffer and Spring instead of the AR-308 Rifle Buffer and Spring.. Quote Link to comment Share on other sites More sharing options...
unforgiven Posted October 26, 2021 Report Share Posted October 26, 2021 Use Armalite recoil system then there is no guessing. Quote Link to comment Share on other sites More sharing options...
billymagg Posted October 26, 2021 Report Share Posted October 26, 2021 7 minutes ago, billymagg said: So did you change the buffer and spring?? and if so, what did you replace it with?? so your gas tube is coming all the way back to the middle of the cam pin cutout in the upper receiver??? pictures of all that please if possible.. if you were 10 out of 10 for not feeding, it sounds like you were short stroking,, a buffer that was too long being out of spec would cause that.. 98Z gave you some great advice, did you measure the gas port bore?? report that bore diameter back please.. One Armed Eye Doc asked you about the length and source of rear receiver extension, should be 9.625 inches These guys KNOW, they are NOT guessing or taking a stab in the dark,, if you follow their very specific advice and give them GOOD information, they will get your rifle running reliably... or you've got it all figured out?? and we will never hear from you again?? not likely, but even a blind hog finds an acorn once in a while... Okay, I see that the receiver extension comes in the kit, and it should measure 9.625 inches internal diameter.. 12 hours ago, unforgiven said: Use Armalite recoil system then there is no guessing. absolutely a no brainer, even I can figure that one out... Quote Link to comment Share on other sites More sharing options...
billymagg Posted October 26, 2021 Report Share Posted October 26, 2021 2 hours ago, billymagg said: Okay, I see that the receiver extension comes in the kit, and it should measure 9.625 inches internal diameter.. absolutely a no brainer, even I can figure that one out... sorry, internal depth Quote Link to comment Share on other sites More sharing options...
98Z5V Posted October 27, 2021 Report Share Posted October 27, 2021 8 hours ago, billymagg said: sorry, internal depth Internal on a rifle extension should be 9 11/16". What you have posted is 9 5/8". Probably still work, but the spec is 9 11/16". Quote Link to comment Share on other sites More sharing options...
billymagg Posted November 8, 2021 Report Share Posted November 8, 2021 (edited) On 10/26/2021 at 8:45 PM, 98Z5V said: Internal on a rifle extension should be 9 11/16". What you have posted is 9 5/8". Probably still work, but the spec is 9 11/16". Yes sir! I've forgotten half what I know? and the other half is probably wrong,,, but at least I've got some time to get back to the 307 AR forum,, maybe I can soak up some more accurate figures... 9 11/16" whats the 307 forum?? oh well, I can't keyboard either,, thank you to the 308 forum mods and 98Z5V.. and all you other bright lads, probably time to put this thread to bed. Edited November 8, 2021 by billymagg Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.