So this was one of my first builds last year. I've been slow to trouble shoot it as I just haven't had time to dedicate to the range and really give it a thorough going over. Today was my first real chance, here's the history and where I'm at now:
Build:
- Stag 10 receiver set
- Brownells BCG
- XCR-M pistol mags
- Maple ridge barrel
- PWS Mod 2 Enhanced buffer tube
- Strike Industries Flat Wire Carbine Spring
- Maple Ridge Armoury Pincer Gas Block
Problem 1: First issue was the known mag issue, the mag release would not catch them and so the mag would not stay in place.
Solution 1: As posted on the form I did some light sanding with some files and got them to latch.
Problem 2. Latch was weak and if I fired a round the mag would drop out and release.
Solution 2: Rather than doing more sanding I found a spare latch I forgot I had and replaced the stock one. Mags catch every time now.
Problem 3: Secondary problem that I thought was attributed to the mag issue did not go away. The bolt will not always fully close on the round when fed, it closes 80% of the way and leaves a half inch gap just short of the round. Obviously resulting in a failure to fire. This was happens about 80% of the time. I found that the only time I could get it to fully close was if I manually fed a single round and then racked it viciously. A light racking or simply releasing the bolt catch would not do it. Now I didn't get to test this much and only fired off a few rounds over two visits. I had new shooters with me I was introducing to the sport so we stuck with the guns that were firing.
Solution 3 - sort of: I was hoping this was a stiff bolt issue, new parts and all. I oiled it again and with some snap caps just kept working it for a couple of hours while watching TV. At first it was repeating the same issue. Eventually I got it to feed and extract the rounds manually 100% of the time. I thought I had it nailed.
Problem 3.5: Today the problem persists (note that all shooting has been in the winter). I was alone today so I got to do more trouble shooting to try and figure out what exactly was happening. So first off it has improved from last time, if I manually load a single round and release the bolt catch or just pull back on the charge handle it will fully close 95+% of the time, but not every time. It also works the vast majority of the time if I only load a single round in the magazine. It feeds the round fine and the bolt fully closes on it. However, on occasion still stops short and doesn't fully close. The real problems manifest when I load more than one round in the magazine. So 2+ loads and it won't feed the second load. I think only once did it catch the second round and that jammed in the chamber. Again, if I drop the mag, and re-insert the same mag with only one round, no problem. However, as soon as I add more rounds to to it, it will only fire the first one (60% of the time) and then won't load the second.
Any ideas for this newb to start trouble shooting? Could this be the carbine length buffer system vs rifle length barrel and gas system? Looking for ideas and feedback from those wiser than myself, before I start playing with things. Thanks guys. I do have pictures, but not with me now. If the problem isn't clear I can post those.
Build:
- Stag 10 receiver set
- Brownells BCG
- XCR-M pistol mags
- Maple ridge barrel
- PWS Mod 2 Enhanced buffer tube
- Strike Industries Flat Wire Carbine Spring
- Maple Ridge Armoury Pincer Gas Block
Problem 1: First issue was the known mag issue, the mag release would not catch them and so the mag would not stay in place.
Solution 1: As posted on the form I did some light sanding with some files and got them to latch.
Problem 2. Latch was weak and if I fired a round the mag would drop out and release.
Solution 2: Rather than doing more sanding I found a spare latch I forgot I had and replaced the stock one. Mags catch every time now.
Problem 3: Secondary problem that I thought was attributed to the mag issue did not go away. The bolt will not always fully close on the round when fed, it closes 80% of the way and leaves a half inch gap just short of the round. Obviously resulting in a failure to fire. This was happens about 80% of the time. I found that the only time I could get it to fully close was if I manually fed a single round and then racked it viciously. A light racking or simply releasing the bolt catch would not do it. Now I didn't get to test this much and only fired off a few rounds over two visits. I had new shooters with me I was introducing to the sport so we stuck with the guns that were firing.
Solution 3 - sort of: I was hoping this was a stiff bolt issue, new parts and all. I oiled it again and with some snap caps just kept working it for a couple of hours while watching TV. At first it was repeating the same issue. Eventually I got it to feed and extract the rounds manually 100% of the time. I thought I had it nailed.
Problem 3.5: Today the problem persists (note that all shooting has been in the winter). I was alone today so I got to do more trouble shooting to try and figure out what exactly was happening. So first off it has improved from last time, if I manually load a single round and release the bolt catch or just pull back on the charge handle it will fully close 95+% of the time, but not every time. It also works the vast majority of the time if I only load a single round in the magazine. It feeds the round fine and the bolt fully closes on it. However, on occasion still stops short and doesn't fully close. The real problems manifest when I load more than one round in the magazine. So 2+ loads and it won't feed the second load. I think only once did it catch the second round and that jammed in the chamber. Again, if I drop the mag, and re-insert the same mag with only one round, no problem. However, as soon as I add more rounds to to it, it will only fire the first one (60% of the time) and then won't load the second.
Any ideas for this newb to start trouble shooting? Could this be the carbine length buffer system vs rifle length barrel and gas system? Looking for ideas and feedback from those wiser than myself, before I start playing with things. Thanks guys. I do have pictures, but not with me now. If the problem isn't clear I can post those.
