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Posted: 6/18/2007 8:11:38 AM EDT
| How used was your upper? I have noticed that the older uppers here in the Army have alot of slop in them as well. I think after time this happens. I know that my A1 upper I have fits tight with new pins, but my upper was a NOS upper. I would not think that it would be a problem with the lower if the pin fits it. |
| Are you sure its not your front pivot pin hole on the upper? You may have a large hole upper. Look at the front pivot pin lug. If that hole is larger (.315" i believe..somewhere around there) than the lower pivot pin holes or the rear takedown pin hole on the upper (.250"), then you have a large hole. |
| Probably an upper problem and not a lower problem. Try putting the upper on another lower and see what happens. Alot of these uppers (even if rebarreled) have had ALOT of rounds put through them which results in some widening of the diameter of the holes. If it really bothers you, you could always drop a couple of bucks for an accuwedge and solve your problem... |
| I mounted the upper onto my eagle arms A1 type lower, and the looseness is even more noticable. As was suggested, looks like the problem is in the front pivot pin hole. The upper is fairly old, but not many rounds through it. In terms of fit and function, the NDS lower is first rate. not sure how to fix this. Probably not that great a problem, as the rifle functions fine in all other respects. Just a nuisance at this point. |
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Sounds like you have an easy solution, then, since you have a commercial upper. Just get one of these. www.bushmaster.com/shopping/lowers/we-003.asp |
| Yes, it has a forward assist. Receiver is marked "CH", which was a supplier to Colt. It's an issue upper. The front pin seems to fit the hole perfertly tight. Also, the looseness seems to be centered at the rear takedown area, not in the front pivot pin area. I purchased it many years ago from Quality Parts, who used to advertise on Shotgun News. Paid 75.00 new. Those were the days..... |
In other words, the rear takedown hole in the upper is slightly oblong. It's supposed to be so, to allow for minor differences in upper/lower dimensions. There is almosr certainly nothing wrong w/your piece. It's just one of the looser fit ones. 
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| The problem is definately in the pivot pin hole on the upper. I took the rifle to the range yesterday and fired about 40 rounds. Everything worked perfectly. I think it's a problem I can live with for now. By the way, firing the rifle actually tightened up the rifle somewhat. Not sure why. Recoil maybe. I'll probably get an accuwedge later. Anyway, thanks for all the helpful suggestions. |
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eagle15, Instead of an accuwedge, you could just put a small rubber o-ring around the upper's front lug, so that the o-ring is sandwiched between the upper and lower receivers. I've never actually tried this, but remeber it being mentioned here on Arfcom before. Hope this helps! |
| I decided to install an accuwedge to see what would happen. It really tightened up the rifle. Nice little invention. According to Fulton Armory, Colt is now installing these in most AR15's in the factory before shipment. Never heard of that before. Anyways, it did do the trick, although it does make pushing out the pin for breakdown alittle more difficult. Nice item for 4.95. |
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