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Posted: 6/5/2005 7:59:36 AM EDT
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OK, so I got it all built and out to the range to sight-in, and it basically ran flawless with my usual xm193 ammo. No FTF, FTE, etc. the only problem I had was that sometimes after I would run a mag dry and insert a "full" (28 rounds) one the bolt wouldn't close. I use the "slap the bolt hold open" method so there's no issue of riding the bolt home. Generally it would partially strip the first round out of the mag, and if I pulled the bolt back and let fly again it would be good to go. Ordinarily I would suspect the mags except that these are the same 10 mags that I run in my other three ARs all the time. The only thing that's changed in these mags was the addition of Magpul followers, which I can't imagine changed the function like this. Here's a pic of the rifle just to be clear.  List of parts: CMT upper J&T chrome-lined LW barrel DD 7.0 forend RRA stripped lower RRA LPK Ergo grip CMT bolt/carrier unknown charging handle Vltor stock, buffer, receiver extension, buffer spring |
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How old is the action spring? Compare length to a known new one? If it needs a little extra help to chamber that first round it may be that the action spring has lost its full power. That's the toughest job I can think of for the action spring; stripping the first round and chambering it from a full magazine starting from the bolt hold-back position. |
I've always run my ARs pretty dry and pretty dirty with no problems. Any suggestion as to what part might need additional lube? |
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I was thinking more along the lines that the weapon needed to be broken in, and that your other weapons had been lubed and run in the past. I've had weapons in the past that were a bit stiff with the bolt catch, but after running drills, they all settled out. Why not work some dry fire drills with a mag of dummy rounds and see how it goes? When there is no mag inserted in an empty weapon, how does you bolt catch work? Can you lock it back and release it without any problems? Does it feel like your other ARs? I'm getting ready to jump in my cruiser, so I'll check back in another 16hrs. No posting on duty.... |
I just got done trying it with no mag, and with an unloaded mag, and the catch appears to work perfectly. I had no trouble locking it back or dropping the bolt with an empty magazine in the well. Hopefully it really is just a break-in issue. Next time I head to the range I'll try lubing up the bolt carrier a bit more and see if that helps. |
| Might be a mag issue as well. It seems that if it's only on the first round or so the added tension on the feed lips from the full mag restricts the bolt/bolt carier from going forward, completing it's function. I wouldn't bend any lips yet but you may want to look at them, little 400 Emery on the under side maybe? |
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Hmmmm, I don't know what to think. My 2 AR's had hiccups in the first 30-40rds, but ran well aftr that. My third one, I just got it together yeasterday and have shot it twice so far, already has 160rds through it in 2 days, and it hasn't hiccupped yet. My RRA 20" A4 did the same thing you're talking about three times the first time I shot it. After that, it ran great. Make sure there isn't any kind of burr, or lip, in the area of the feedramps for the round to hang up on. WIZZO |
Thanks smartass |
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