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Posted: 12/27/2012 9:24:32 AM EDT
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Hi Guys,
I just built a new A2 5.56 carbine out of new/used parts and took it to the range for the first time yesterday. After holding the bolt back, inserting the mag, and releasing like usual to charge it, it will only push the round 1/2 to 3/4 into the chamber. Rounds are not scraped or marred, and the casings appear fine. I can't push the forward assist to get it to go into battery. The jammed round will also be very difficult to clear, as I can't pull the BCG back without effort. Occasionally, I can force it all into position and fire it, but it will happen again to the next round as it cycles. After reading everyone else's feeding problems on the board, I can't seem to figure it out. My only uneducated guess is that there isn't enough pressure coming from the buffer spring to return everything to full battery, but that just seems stupid. Here are my specs: Rifle upper (no feed ramps, used) M4 barrel (with M4 feed ramps, new) Umlaut 5.56 lower (used) Carbine buffer tube/spring (new) Pmags, Lancer mags, and steel mags (all tested) Shooting Wolf ammo, which I know is not the best, but I have honestly never had any problems with it before. Here's what I [think] I know: The gas system seems to be working properly, as it will cycle all the way back. I did the usual "blow into the barrel" test and it felt normal. Casings are being sent 10'-15' away, when ejected. The rifle upper with no ramps and barrel with m4 feed rampsl are apparently compatible, according to all sources I can find. There is a little slop between the upper and lower, but mot much and it doesn't seem out of the ordinary from other rifles. I've tried all 3 different kinds of mags, and they appear to seat properly when inserted. They all work on other rifles, no problem. All is lubed and manually cycles smoothy, when not loaded. No burrs on the feed ramps, shavings, or anything strange in the barrel. All is smooth. What in the world am I dealing with? Edit: I had not mentioned that I took apart the carbine buffer because I was getting annoyed with the rattling weights and put in felt spacers to get it to stop. It seems that they are held in place loosely in order to provide a dead-blow by slamming back and forth inside the buffer, and stopping this may contribute to my BCG not being forced into battery correctly. I'm going to take them out and take it back to the range to see if this might be it. Regardless, if anyone has any extra insight on my problem, it would be welcome! |
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Quoted:
Hi Guys, I just built a new A2 5.56 carbine out of new/used parts and took it to the range for the first time yesterday. After holding the bolt back, inserting the mag, and releasing like usual to charge it, it will only push the round 1/2 to 3/4 into the chamber. Rounds are not scraped or marred, and the casings appear fine. I can't push the forward assist to get it to go into battery. The jammed round will also be very difficult to clear, as I can't pull the BCG back without effort. Occasionally, I can force it all into position and fire it, but it will happen again to the next round as it cycles. After reading everyone else's feeding problems on the board, I can't seem to figure it out. My only uneducated guess is that there isn't enough pressure coming from the buffer spring to return everything to full battery, but that just seems stupid. Here are my specs: Rifle upper (no feed ramps, used) M4 barrel (with M4 feed ramps, new) Umlaut 5.56 lower (used) Carbine buffer tube/spring (new) Pmags, Lancer mags, and steel mags (all tested) Shooting Wolf ammo, which I know is not the best, but I have honestly never had any problems with it before. Here's what I [think] I know: The gas system seems to be working properly, as it will cycle all the way back. I did the usual "blow into the barrel" test and it felt normal. Casings are being sent 10'-15' away, when ejected. The rifle upper with no ramps and barrel with m4 feed rampsl are apparently compatible, according to all sources I can find. There is a little slop between the upper and lower, but mot much and it doesn't seem out of the ordinary from other rifles. I've tried all 3 different kinds of mags, and they appear to seat properly when inserted. They all work on other rifles, no problem. All is lubed and manually cycles smoothy, when not loaded. No burrs on the feed ramps, shavings, or anything strange in the barrel. All is smooth. What in the world am I dealing with? Edit: I had not mentioned that I took apart the carbine buffer because I was getting annoyed with the rattling weights and put in felt spacers to get it to stop. It seems that they are held in place loosely in order to provide a dead-blow by slamming back and forth inside the buffer, and stopping this may contribute to my BCG not being forced into battery correctly. I'm going to take them out and take it back to the range to see if this might be it. Regardless, if anyone has any extra insight on my problem, it would be welcome! There is a reason why the buffer was designed to allow the weights to move freely. Remove the felt and this will probably correct the issue. |
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Quoted:
What would the mag catch be doing in this case to stop the cycling? Sorry, dumb question, I'm sure. There is never a dumb question when it comes to firearms. To answer your question, it can allow the mags to sit too low or have too much movement, changing the feed angle. |
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Okay, so a new development; I took it to the range yesterday finally, to put some rounds through it. All was pretty normal, which means that every 5-6th round would jam. It would get almost all the way into battery then stop. If I pulled back on the charging handle and release, it would push it in.
Well...turns out that I separated a bullet from its casing inside the chamber doing this and ejected a casing full of gun powder, and the bullet is actually stuck in the barrel now. I had enough of this BS, so the rifle is at a [very surprised] gunsmith at the moment for a damage assessment. This is complete crap. |
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Chamber cut improperly. The bullet is engaging the rifling before it is fully closed into battery. Good thing you caught it when you did because that can cause all kinds of serious problems. Like over pressure from the bullet being pushed into the casing to far or firing a round after a bullet was left in the bore like you experienced If you bought the barrel new or if you bought a complete upper receiver new, get the manufacturer on the phone to get a replacement. I know it sucks because of the way stuff is right now with everyone being sold out, and not knowing when they will have something back in stock to replace it with, but don't let that get in the way of you having them make it right and getting a replacement. That's if you bought it new. If you bought it used, get whoever you bought it from on the phone and get your money back if what you got wasn't as advertised. |
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Quoted:
Chamber cut improperly. That's my guess too at this point. I bought it from Midway, advertized as an AR Stoner barrel, but there wasn't a single marking on the box it came in or the barrel itself (which should have tipped me off, but I wasn't expecting this). I mangled it a little (just the bluing, nothing structural) getting the FSB on and I cannot imagine they'd take it back now. I'd like to see what my gunsmith comes back with, and whether it's salvageable, and whether it can be fixed. Anyone think the barrel can be saved? You're all right, with parts availability like it is these days, I don't really want to give it up if I don't have to and wait... |
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