SHAKEWELLBEFOREUSING

I don't doubt that you can tune a m4 carbine system to work, but I was taking the previous suggestion to use a rifle system for simplicity as well. I tried to order a heavier buffer to start with initially but ordered two h3 carbine size buffers on accident, which are too long lmao. At least I got enough tungsten to replace the steel weights in the rifle buffer. I got the rifle buffer system in today and the bolt face pulls back behind the magazine bolt catch. It does not do that with my M4 carbine buffer system. The bolt catch just catches on the bolt body so that the bolt face is even with the magazine well. I assume the the M4 carbine buffer system may have other issues than just buffer weight if the bolt can't move far enough back? I did take it to the range today with the stock AP rifle buffer weight of 5.6 oz. It performed a bit better but would only shoot about 3 rounds before missing the next. Definitely needs a heavier buffer than 5.6oz IMO. In that sense, I'm happy I didn't order the 2.5" 5.4ox kak buffer. Progress is progress?

I ended up skipping the red spring and getting the complete rifle buffer kit for the 308. I should have probably just built a fixed stock from the get-go to match the barrel length and gas system. No doubt it should work at that point. Ap customer service did get back to me and made the same suggestions with regards to the specs since I'm mixing a m4 buffer system with a rifle gas system. They immediately suggested a heavier buffer. Since encountering the issue I learned that a rifle length stock and buffer could shoot a lot smoother than m4 carbine so I began to see the positives in the A2 buffers. That really made me prefer that over just using a heavier buffer. I will report back on results after install.

Noted, that makes total sense. After all if a round can't make it into the chamber then why would the magazine be fast enough to stop the bolt.. don't know why I thought otherwise. The current setup is all AP m4 standard 7" buffer tube, 308 buffer spring, and the 2.5" buffer ~3.8oz. I'll pickup the red spring to match the 7 5/8" internal depth extension buffer tube and h3 buffer. If that doesn't work then I'm going to just get a full fixed stock system. This gun would probably be better balanced with that anyways since it has a heavy ss barrel on it.

I believe it but the bolt not locking back on the last round confuses me. I've got another buffer tube coming. I'll use my spare h3s and orange spring. In the mean time I'm gonna manually cycle it until the spring shows a decrease in length and lube it like a threatened catfish.

About 25...maybe I just need to be patient. I have an AP m4e1 that just friggin runs like a top no matter what.

I do have two different h3 buffers on hand but they were too long for this tube so I may just pick up another tube. Trying to not throw parts at this lol. Tubes are cheap, though. Sorry for the double post.

I see that when compared to ar10 specs but I don't want to compound a short cycling issue with a heavier buffer at the moment. I'm not sure how a heavier buffer will help?

I just built an M5 using all new AP parts: 18" complete upper with rifle gas system m4 carbine complete lower (came with 7" receiver extension tube, 11" buffer spring, 2.5" buffer at 3.8oz) AP BCG -The gun does not chamber the proceeding round and will not catch on the magazine on the last round fired. I'm using federal premium retail ammo. -The gas port is 3/32" -The gas tube lines up with the middle of the cam route out. -The gas block does not seem to be leaking. -The bcg gas key is tight and staked; shows no signs of leaks. -gas rings aren't lined up or damaged -I've tried the sprinco orange spring and it does not improve anything in this instance. My assumption at this point is that the 11" 26 coil buffer spring is too stiff and/or long? I can lock the bolt back manually. The bolt face is flush with the magazine well rear wall. It does not go farther back. Issue persists with multiple magazines. The next round always gets scratches from the bolt scraping across its side. I submitted a ticked to AP, but I'm sure they're busy right now...