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Posted: 4/11/2026 4:21:07 PM EDT
| Hey y’all, I have a first time build, a Stag 10 AR10, got the lower and upper together as it’s Armalite but everything else is DPMS. I went with a standard AR15 milspec collapsible stock and buffer tube system. When I took the gun into a gun smith he had me get a Tubb SR-25 rifle and carbine buffer spring with a PWS H4 weight because what came with the kit would be insufficient since .308s are known to be overgassed. I have a suppressor for it and barrel is 16”. The problem is it’s short stroking either because the weight is too long or the tube is too short to handle the longer spring and carbine length buffer weight. I pushed the bolt as far as it could go and it’s around 3/4” short what where it should go back. My question is can I just get an A5 length tube and will that work with the carbine length buffer and spring setup I have with the stock as long as it’s milspec. Or would I need an actual A5 length buffer going that route? Would a shorty buffer work with my standard tube and the longer spring? I guess what’s the most simple fix here? Thank you guys! |
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Not sure what you have exactly for parts without seeing it, but sometimes the AR10/AR308 bolt carrier is longer in length as compared to the AR15/M16. This requires a shorter in length buffer. When we build these types of, we use buffers that we get from Heavybuffers.com CY6 Greg Sullivan "Sully" WeaponsArmorer SLR15 Rifles Defensive Edge Training (763) 712-0123 |
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If I am understanding you correctly, ( AR15 Carbine length buffer tube, and a 3.25" buffer ), then yes you will need a A5 buffer tube length to use your PWS H4 buffer. To be blunt, that would be cheapest. FWIW... what gas length are you using ? .... and you might want some kind of adj. gas system. |
*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man.
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JAFOM.... Just another fat old man.
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| I’m not sure if there’s an easier way to post pics but this site wants a url. Yes that’s correct. I’m using an SL adjustable gas block mid length system and just purchased the V seven weapon systems A5. I did a bit of digging last night to see if I could find the answer I was looking for and I think it’ll work as long as the bolt doesn’t bottom out the buffer is 3.25” and the spring is 20” uncompressed and the standard white coated spring that came with the PSA kit is about 10.625”. If it doesn’t work I guess I’ll just have to grab an A5 length buffer. Thank you for your input. |
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| I remember seeing someone else recommend the heavy buffers products before. I think I’ve got the right idea with getting the A5 tube instead of going with a shortie weight from some digging around last night, but we’ll see once it comes in, as long as it doesn’t bottom out it’ll be an improvement. I’m not sure how to upload pictures as it says it wants a URL. But the buffer is 3.25” and the spring is a 20” uncompressed David Tubb’s SR25/AR10 (rifle and carbine) flat wire buffer spring and I have the SL adjustable gas block on a mid length system. Thanks for your input. |
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Originally Posted By Spritzy1551: I remember seeing someone else recommend the heavy buffers products before. I think I’ve got the right idea with getting the A5 tube instead of going with a shortie weight from some digging around last night, but we’ll see once it comes in, as long as it doesn’t bottom out it’ll be an improvement. I’m not sure how to upload pictures as it says it wants a URL. But the buffer is 3.25” and the spring is a 20” uncompressed David Tubb’s SR25/AR10 (rifle and carbine) flat wire buffer spring and I have the SL adjustable gas block on a mid length system. Thanks for your input. Just a pic to show how much a flatwire spring compresses v. a round wire. (5.56 version )  In a nut shell... the LFAR BCG is 3/4" longer than a AR 15 BCG.... so any buffer setup, needs an additional 3/4" travel in said buffer tube. this thread shows the dimensional differences between the 2 buffer lengths when used in a Large Frame AR ( LFAR ) https://www.ar15.com/forums/industry/PSA-when-did-you-guys-switch-the-buffer-system-length-on-the-PA10-/301-286585/ All my LFAR's rely on an Adj. GB , more than a very heavy buffer weight. However, I still use a approx. 5.4oz buffer weight ( in general ) in either buffer length. Ultimately , Limiting gas flow has worked best for me. |
*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man.
________________________________
TOGC,IADC
JAFOM.... Just another fat old man.
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TOGC,IADC
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And to post pics... use the attach Image at the bottom of "Post Editor" ( when posting a response ) push "select Image" , choose one from your computers Pictures. Double click your choosen image, Then press Upload. Then press submit. 
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*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man.
________________________________
TOGC,IADC
JAFOM.... Just another fat old man.
________________________________
TOGC,IADC
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Additional info on the Tubbs "308" buffer spring. https://www.ar15.com/forums/ar-15/Tubb-Flat-Wire-Buffer-Spring-in-PA10/121-760149/ |
*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man.
________________________________
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JAFOM.... Just another fat old man.
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Originally Posted By bfoosh06: And to post pics... use the attach Image at the bottom of "Post Editor" ( when posting a response ) push "select Image" , choose one from your computers Pictures. Double click your choosen image, Then press Upload. Then press submit. https://www.ar15.com/media/mediaFiles/171545/________________________________________-3745310.jpg Right on, thanks for all the info. I don’t know if it’s because I’m using a phone but at the bottom of the post editor is all the emojis and a gif icon, as well as, attach a deal. At the top is an icon for inserting a picture but it doesn’t give a choice for selecting anything, it just has a url prompt along with a link icon and the bold italic etc icons. Attached File Maybe I’m missing something. |
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Lets back it up, since the Armlite carrier slot for the hammer is narrower, and you have to use the narrow Armalite hammer (or an after market trigger group that has the narrower Armalite hammer width. Next, if the bolt and barrel are both Armalite spec'd, then head spacing should be correct. If a mix or DPMS/stoner bolt, and armalite spec chamber bolt (or visa Vera), then head spacing is going to be way off. As for buffer and spring, Face of the bolt needs to retract behind the back of bolt catch by 1/8~1/4", without the buffer spring coil binding on it self before the end of the buffer does touch the back of the receiver extension void. And on the end this math, if the face of the bolt is retracting much greater than this distance behind the bolt catch, you can chance the back of the carrier key crashing into the lower receiver front face of receiver extension ring to crack it off the lower receiver. So the easy solve to this problem, is with buffer and spring in play, pull all the way back of the charging handle, and determine where the face of the bolt is stopping in regards to the bolt catch on the receiver. If too far back behind the bolt catch, then you can add a buffer tube spacer of the correct lenght to the back of the receiver extension to limit how far the buffer/B-C can retract back in the tube. If not enough, then comes down to what buffer is in play, and shorting the buffer (buffer bumper is just a short distance, may be the option instead; while making sure that the recoil spring is still not coil binding out on itself. Now once that has been corrected with correct buffer and recoil spring length, and the fact of this being a 308, then we get into the weigh of the buffer, and even the tension of the correct length buffer spring to have the bolt unlock at the correct unlock timing. Bolt unlocking too soon, or even too late, is going to end up with the rifle short stroking. With bolt unlocking too soon, the residual pressure in the bore will still have the spent case too pressure welded still for the bolt/extractor to allow a clean pull of the spent case from the chamber, which reduces the amount of momentum that the B/C does have to full stroke correctly (too much energy lost of the bolt pull of the spent case. |
Posted By PlaymoreMinds:
'Twas not the <cough> sweet and innocent <cough> PlaymoreMinds...
<---skips away in frilly skirts to Candyland, leaving gutters and snorkels FAR behind.
'Twas not the <cough> sweet and innocent <cough> PlaymoreMinds...
<---skips away in frilly skirts to Candyland, leaving gutters and snorkels FAR behind.
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And yes, depending on the suppressor, if not a low back pressure type, then this raises the gas port pressure in the barrel, that will cause the bolt to unlock sooner. So back to buffer weight, in most cases if the suppressor is not producing a ton more back pressure, you can dial in the rifle/buffer weight to cycle correctly with out suppressor (correct bolt unlock timing), and then to run suppressed, a quick recoil spring swap in the correct lenght from standard tension, to extra tension spring, should be all that it takes to run the rig either way. If suppressor does have a ton of back pressure (standard concial baffle type), then may have to come up with two different buffer weights on the same recoil spring isntead to have the rig cycle correctly either way. And just a FYI, but most commercial barrels are chambered on the tighter side of 308 specs, to promote accuracy, instead of the the looser Nato chambers that promote reliability instead. So check the chamber with head spacing gauge, and make dam sure that the chamber is as smooth as glass, with no reamer chatter ridging instead. If barrel chamber is not smooth as glass, then may be time to send the barrel back to have it replaced. In some cases, you can run a reamer by hand, or polish the chamber is the cross wall specs are too tight, but these are not an option when chamber sidewalls are to correct spec, since will end up with chamber way too large in cross wall dimensions in the end. |
Posted By PlaymoreMinds:
'Twas not the <cough> sweet and innocent <cough> PlaymoreMinds...
<---skips away in frilly skirts to Candyland, leaving gutters and snorkels FAR behind.
'Twas not the <cough> sweet and innocent <cough> PlaymoreMinds...
<---skips away in frilly skirts to Candyland, leaving gutters and snorkels FAR behind.
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@Dano523.... You have all very accurate comments. I would like some more info from the OP @Spritzy1551.... if possible could you add info. FWIW....STAG has sold slant cut receiver sets ( AKA Armalite pattern ) , with DPMS pattern threads at the for the barrel threads. Given the OP's comment in the first post, I "assumed" that is what he has. Maybe I am wrong... but the OP should please clarify this. Given the following info... I would also "assume" the OP is using the correct DPMS parts ( sans the buffer tube length ) PLEASE If I am completely wrong, some one correct me !! To be honest, when those uppers and lowers came out ....All I could think was "Way to muddy the waters on LFAR's even more than the DPMS v. Armalite differences..... Arrgh STAG. I realize their intent was good natured... but.... Dang.... what a way to cause confusion.... "2" common patterns was enough ?! ( I can only dream about MilSpec guidelines for the LFAR platform ) https://www.stagarms.com/stag-10-rh-upper-receiver "The Stag 10 Stripped Upper Receiver includes a picatinny rail on the top with a Tang Height of .210 Compatibility: The Stag 10 Stripped Upper Receiver will work with our Stag 10 Upper Receiver Parts Kit or any DPMS upper parts kit. Our upper receiver has the same barrel nut threads as DPMS, accepts DPMS barrels, accepts Stag, Armalite and DPMS BCGS and Charging Handles. It also accepts standard AR Forward Assists. Once matched with our custom Stag Lower, Takedown Pin, Pivot Pin and Takedown Pin Detent, this assembly can be built using standard DPMS components." Lower... https://www.stagarms.com/stag-10-stripped-lower-receiver-black "Made to work with our Stag 10 components and some DPMS components. Our Stag 10 Stripped Lower receiver is second to none in quality. This lower comes with our proprietary takedown and pivot pin set for superior fit with a Stag Upper Receiver. Compatibility: Once matched with our Stripped Upper, the use of standard DPMS components and magazines is accepted. The Stag Stripped Lower accepts any Mil-Spec Trigger Guard, Mil-Spec Fire Control Group, Mil-Spec Stock, DPMS Magazines, and Standard AR15 receiver extension tubes with a .308 Buffer and Buffer Spring. Accepts any standard AR Pistol Grip." AI .... I dislike AI, but it does sum it up. "Stag Arms Stag 10 (Hybrid Pattern) The Stag 10 utilizes a hybrid approach: DPMS barrel/thread pattern but a slant-cut rear receiver similar to the Armalite AR-10. Barrel Threads: DPMS pattern (1-7/16" x 16). Handguards: DPMS High profile. Receivers: The slant-cut at the back means it is not compatible with Aero Precision M5 receivers. Proprietary Parts: Uses proprietary takedown and pivot pins. Stag 10 receiver sets often include these proprietary parts." "Barrel Compatibility: Both Stag 10 and Aero M5 uppers accept standard DPMS-pattern (.308 LR-308) barrels. Handguard Compatibility: Both use the "DPMS High" (.210") profile. Lower Parts: Aero M5 generally uses standard DPMS/AR15 LPKs (with exceptions for the bolt catch). Stag 10 requires specific takedown/pivot pins. Compatibility Warning: Do not attempt to mix a Stag 10 upper with an Aero M5 lower (or vice versa) as the rear receiver cuts (round vs. slant) and pins do not match. " |
*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man.
________________________________
TOGC,IADC
JAFOM.... Just another fat old man.
________________________________
TOGC,IADC
|
A thread about the AERO / STAG sold by Aero... https://www.ar15.com/forums/ar-15/Aero-Stag-10--/121-786631/? |
*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man.
________________________________
TOGC,IADC
JAFOM.... Just another fat old man.
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| AI is correct. I bought the lower and upper assembled from Aero which came with the proprietary takedown pins, everything else is DPMS. I took this to my gun smith to have headspace checked before firing to make sure it was safe. I’ve already fired it and was having loading issues so I don’t believe the trigger needs to be armalite, and I certainly didn’t buy one specifically that said it was, thankfully doesn’t seem to be the case. I had to buy the Stag since left handed ejection firearms are extremely hard to come by, maybe there are a couple more options now, but it’s not easy shopping for a lefty sometimes. After posting this originally, I was able to find a video that said to push the BCG into the buffer to see if it comes up short and that is the case, so I just ordered an A5 since the extra length seems to be right around what I need for space I just wasn’t sure if a normal carbine length buffer weight was long enough since I did see on the original manufacturers website the one that starts with a V, said they recommend the A5 length buffer, but then others have said the A5 works with a carbine length buffer. I think it might have been after that I asked AI and they said the PWS buffer should be compatible but I guess we’ll see once I get it installed to check. |
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You are on the right track. And Thank You for clarifying. As mentioned the Vltor A5 buffer tube, when used with a LFAR, uses a standard AR15 carbine length buffer. ( 3.25" ) This works because the 308 BCG is longer than a AR15 BCG by 3/4"... so, while the Vltor A5 buffer tube is longer... that 3/4" is used by the extra travel of the 308 BCG , and the 3.25" buffer is needed. ( Math , Lol ) |
*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man.
________________________________
TOGC,IADC
JAFOM.... Just another fat old man.
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TOGC,IADC
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The A5 from V seven came in and I must say this thing is pretty nice. It’s got a faceted outer surface and 11 positions machined very slick. I got it all installed and BCG was bottoming out, it must have been close because I only stuck two quarters in there and everything seems to be lined up well somewhere between an ⅛”-¼” behind the bolt catch. Now to take her out to dinner and see if she’s going put out this time haha. Thanks to everyone who chimed in with your  knowledge. I appreciate you guys and this community!
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