Troubleshooting the AR-15 Pistol platform: Problems and fixes



Hey guys and gals,

After a lot of research, and a lot trial and error with my own AR-15 pistol build, I made this video to help anyone that is wanting to build, or maybe already have built an AR pistol, troubleshoot any problems that may arise after you have your gun assembled.

These guns can be very finicky, and if you’re not familiar with some of the problems that can be tossed in your lap, you’ll not only be caught off guard, but frustrated as well. I hope this video helps anyone with any problems they may be experiencing, or with any questions you may have before diving into a build. If you have any questions, or comments, don’t hesitate to ask, or share your experiences, and knowledge. Thanks for watching, have fun, and be safe!

Oh yeah, and try to guess how many times I say the word “Gas” in this vid. LoL.

38 thoughts on “Troubleshooting the AR-15 Pistol platform: Problems and fixes”

  1. g54023 – I have never had a failure to eject, sometimes it happens a little too soon, but boy does it happen!!!!!!!

  2. g54023 – I have had a few failure to extract scenarios, and boy did she get pissed, well, her husband was more upset than she was on the day the baby was born. The baby had red hair, like mine…Buahahaha!

  3. g54023 – I have excessive gas issues, well, when I eat jalapenos that is. But a few Tums and I am good to go!!!!!!!!

  4. If your overgassed Go straight for the adjustable gas block. A different bolt is $100+ a high pressure spring is $40+, an h3 buffer is $50+.
    A good detent click adj gas block is $85. Why would you start with things that might fix it when an adjustable gas block WILL fix it!
    https://www.midwayusa.com/product/788973/ar-stoner-gas-block-low-profile-clamp-on-click-adjustable-ar-15-lr-308-0750-inside-diameter-stainless-steel-melonite

    https://www.midwayusa.com/product/901418/ar-stoner-gas-block-low-profile-set-screw-click-adjustable-ar-15-lr-308-0750-inside-diameter-stainless-steel-melonite

  5. So I have a 7.5" upper and it's .223/5.56. It doesn't lock open after last round shot. It feeds and shoots and ejects fine. The carbine buffer spring feels weak and the bolt has no marking. But I eject at about 3 o'clock. So I've bought a colt carbine buffer spring and a Wolff extra power spring. Gonna run a colt H3 buffer too and I hope I'm good to go. I'll come back and share my results after it's all done.

  6. Quick Question?….. I'm contemplating buying an AR-15 Pistol, just so I don't have to go through all the legal hassle of NFS, and ATF regulations as well as the $200 Tax Stamp. When buying a 10.5" Barrel, should you have a "Pistol Length"; or "Carbine Length" Gas Tube?…… What length is better to prevent having an Overgassing/Undergassing problem on that length barrel?

  7. I just built my first AR pistol and have a 10.5" 223 Wylde barrel on it and the whole 9yards in the pistol but for some reason I can't get it to shoot. it functions fine but as soon as I try to load rounds the BCG will travel about 90% and seized up every round, and I have tested 5 different BCGs in the gun same problem, it's so bad it takes 2 people or a vice to hold the gun just to undo the locked bolt, so in your opinion, do I need to mussel through it and shoot 300+ rounds through it or buy another barrel? also any info you have that might help would be awesome.

  8. that's not what I've understood a bolt override to be. a bolt override is when a casing gets jammed between the bolt face and the charging handle

  9. Great video. I have one and having problems. trying different combos. i would think the shorter the barrel the less gas pressure, idk. what I'm thinking is the time when the bullet passes the gas hole to the time it leaves the barrel is what blows the bolt back. i can see the argument that because of the short barrel more gas reaches the gas hole but I think what happens after the gas hole is more of a factor. mine locks back on last round 3/4th of the time and has ejecting problems 9 times out of 10. gonna try under gassed first. I might be wrong but I will find out.

  10. Nice video – I took my newly built AR-15 pistol (5.56 + 11.5" barrel + M-16 BCG) to the range yesterday. My very first round (bolt lock back test) the bolt failed to lock back. It failed to lock back several times. Next, I experienced problems with extracting & ejection of rounds. I gave up after 40 rounds because I was getting pissed off. I disassembled the rifle after I returned home and inspected bolt carrier group. The bolt carrier group look good. Not much wear on it at all. A couple of scrape marks in the usual areas. I'm going to try a heavier buffer and springs to see if that fixes the problem.

  11. Well G54; it's obvious that you have had 'overgassing' problems, but that's not the only thing that can happen. Mine short cycles

  12. my bolt is locked in with a live round in the chamber I can set the safety but no trigger pull and I can not dislodge it any advice oh and I can't take it apart either

  13. I hope you can help.
    My 6.5" pistol will not lock back on empty mag. It will jam about every 6-7 rounds, and I have to force the round out.

    It looks like the bolt face doesn't clear the bolt catch when traveling backward ( about 1/2 inch short of getting clear). I have a buffer with 3 weights inside, and it measures 3.25 inches long. The buffer tube is 7 " long. the buffer spring is 10.5 inches long. I have no idea if any of this is H2 or H3, etc….
    If I force the bolt catch up via the lever on the both catch, it can get it to lock, but remember, that is locking on the body of the carrier group, not the face of the bolt.
    I hope this makes sense, any ideas how to get this working right?

  14. I have a different issue that I can't figure out….can you make a suggestion? My gun shoots fine. When I'm done shooting, after the barrel has cooled, I will load up a round (brass cased) and a full mag to store in my safe. But, when I go to eject the round manually by pulling back the charging handle, sometimes I can't get it out. Even mortaring is many times very difficult. I cleaned and sanded the locking lugs and it seemed to have helped for now, but any other suggestions? I did notice a few marks on the bullets that were chambered and then removed. My thought was spur in the chamber. Let me know if I'm on the right track or if there is anything else you can think of. Thanks!

  15. 300 black out, pistol length gas, 16" barrel, bolt locks back on last round every time, feeds, extracts, it is not ejecting properly, it stove pipes and leaves spent case in receiver on top of magazine follower on last round hold open. Spent brass is extremely dirty with spent powder, so is the guts of the receivers, I only fired 60 rounds today. Stove pipe ever 4-6 rounds fired. I take it I'm over gassed and should look into getting a adjustable gas block according to your video.

  16. thank you so much for this video!
    I had a four piece Bulgarian Krinkov muzzle booster on my 7" pistol barrel and sure enough! After 200 rounds my bolt lugs were shinny on one side, so I put my A2 birdcage on it.
    sigh
    it's a flame thrower now

  17. Most malfunctions in SBR/pistol AR's caused by carrier/bolt speed, the brass/steel case fails to shrink fast enough in the millisecond after firing and this causes tough or failed extraction, double feeds etc. I have  personal built 8.5 and 10.5  just use a h2 or h3 buffer and enhanced ejector spring,  I have 5 cases of mostly Russian steel case through my 8.5 without a single malfunction. Don't fall victim to the high dollar parts disciples. That being said, don't use junk. I build most of my AR pattern firearms for right around $600 and have yet to have a single failure. I shoot between 6,000 and 10,000 rnds a year. Been Building, smithing and customizing firearms since 81. Good vid, valid info.

  18. Yea the two builds I'm doing are from 80% lowers the one 9 mm pistol and the other 7.62×39 rifle there's lots of good info on YouTube and I realy appreciate everyone advise and help with any proublem that mite occur

  19. Will this cover most or all calibers im working on a build of a 9mm pistol build from what ive read this build has some of these issues. Thanks im saveing this for references  to any proublems i mite run acrss

  20. Tubb's Springs also make a weight that plugs into the end of the bolt. I haven't tried it. I am of the opinion that if you have to go that far you should get an adjustable gas block instead but that is a product on the market that may help someone. 

  21. Sam Muller is 100% correct. One thing to look out for on the low profile adjustable gas blocks is their size. If you choose a hand guard that is pretty tight around the barrel, you may not have enough clearance to fit over the gas block if need be. Most of the low profile adj. gas blocks I've seen are slightly taller than a standard low pro gas block.   Nothing would be more frustrating than spending $150.00+ on a good low profile rail, and have it not fit.

  22. When you build a pistol buy a standard carbine spring and buffer and an adjustable gas block because they are usually over gassed. Adjust the gas block until the empties are leaving the gun at about 45 degs. behind you. Trust me its cheaper to buy an adj. gas block than to replace all the other parts he is talking about. If you have an adjustable block you can tune your pistol for different ammo also, trust me on this it will save you time and money, if your under gassed then that will be a first for me!  

  23. I'm building a 7.5 inch pistol/SBR, so my question is: what would be the best buffer so I don't run into any problems with it?

  24. Don't forget an adjustable gas block to adjust the gas issues.  Just put one a .300 BO 10.5" running suppressor.  Great over view, great job.  I have a 7.5" in 5.56mm, working on these issues right now.  Initially put a pig tail on it, was undergassed.  Replaced with pistol gas tube.  Worked great for first few hundred rounds, now double feeding.  Going to slow mo video it to see what's going on.  Suspect too hot.  Running M16 bolt now with carbine buffer and spring.

  25. thanks for the info and the video. what acutaly causes the initial over-gassing. i ask because i want a pistol but was plaining on buying a barrel for noveske or daniel defence 10.3 or 10.5 and they both have there own gas block already installed so i was hoping to avoid these issues figuring they did all the math on there gas systems.

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