BOOST Posted February 25, 2013 Share Posted February 25, 2013 Can a loose fit cause problems? My brother's Colt seems pretty loose but I havent noticed any issues(same brand upper/lower). I've seen some sets that does not move at all and does not even have an air gap. Im putting together a bushmaster lower / MUR-1 upper and its a little loose. Just wondering maybe it can cause feeding problems. . Havent shot it yet, still waiting for gas tube. Link to comment Share on other sites More sharing options...
Jaxshooter Posted February 25, 2013 Share Posted February 25, 2013 I have never seen an AR that was loose cause any problems. Quite a few of the loose ones I have seen were extremely accurate. Link to comment Share on other sites More sharing options...
vdub5818 Posted February 25, 2013 Share Posted February 25, 2013 (edited) This is one of a few cases where I want a loose fit Really though, a loose fit ensures you can slap whatever upper on that lower or vice versa. Accuracy will not be affected enough to matter. Maybe if you are doing benchrest comp for ultra tight groups you might see a MINOR accuracy difference but not enough for it to matter in real world use. At that point you could bed the upper and lower mating surfaces & lugs to each other, i guess...... Even better is a loose fitting upper lower combo with a lower that has a set screw under the rear lug to tighten it up to your desired tightness. Edited February 25, 2013 by vdub5818 Link to comment Share on other sites More sharing options...
BOOST Posted February 25, 2013 Author Share Posted February 25, 2013 Even better is a loose fitting upper lower combo with a lower that has a set screw under the rear lug to tighten it up to your desired tightness. That sounds like a good idea... I was able to tighten up the upper/lower by turning the buffer tube inwards one full turn, then file the tube down until the desired fit where the takedown pins require some tapping(I could still takedown with MY excessive finger pressure). About 1/8 of material was removed from half way up. Link to comment Share on other sites More sharing options...
9X23Guy Posted February 26, 2013 Share Posted February 26, 2013 A loose upper to lower fit has no impact on reliability or accuracy. It does, however, effect consistency which in turn effects accuracy. Most will never notice. If you're hunting varmints or shooting from a bench you might. I make sure all of my rifles are tight. Link to comment Share on other sites More sharing options...
EkuJustice Posted February 26, 2013 Share Posted February 26, 2013 I have one that is TIGHT to the point you need a punch to push the rear pin. Others that are are on the loose end. On those I put an accuwedge in them and they are very tight for like 5 bucks Link to comment Share on other sites More sharing options...
Nebwake Posted February 26, 2013 Share Posted February 26, 2013 You can always use those little shims, or the camming takedown pins to tighten up a loose upper, but it really does not matter for a battle rifle... Link to comment Share on other sites More sharing options...
BOOST Posted February 26, 2013 Author Share Posted February 26, 2013 Accuwedge? Camming takedown pins? Didn't know there was aid for such.... thanks ill reseach Link to comment Share on other sites More sharing options...
gng4life Posted February 26, 2013 Share Posted February 26, 2013 The accuwedge is little orange piece of rubber that fits under the rear take down pin, normally sells for $5. The cam pin is sold by JP (and maybe others) and just as it says, it replaces the rear takedown pin and you turn it to cam the device to tighten the upper lug to the receiver Some receivers such as Sun Devil, include a set-screw at the rear of the receiver to push up against the rear lug to keep it tight. Link to comment Share on other sites More sharing options...
MickB Posted February 26, 2013 Share Posted February 26, 2013 I have seen these tensioning pins fall out a couple of times during a stage at SMM3G... The accuwedge is little orange piece of rubber that fits under the rear take down pin, normally sells for $5. The cam pin is sold by JP (and maybe others) and just as it says, it replaces the rear takedown pin and you turn it to cam the device to tighten the upper lug to the receiver Some receivers such as Sun Devil, include a set-screw at the rear of the receiver to push up against the rear lug to keep it tight. Link to comment Share on other sites More sharing options...
TRUBL Posted February 26, 2013 Share Posted February 26, 2013 I have seen these tensioning pins fall out a couple of times during a stage at SMM3G... The accuwedge is little orange piece of rubber that fits under the rear take down pin, normally sells for $5. The cam pin is sold by JP (and maybe others) and just as it says, it replaces the rear takedown pin and you turn it to cam the device to tighten the upper lug to the receiver Some receivers such as Sun Devil, include a set-screw at the rear of the receiver to push up against the rear lug to keep it tight. Yeah.... a little blue loctite goes a long way on those things. Tim Link to comment Share on other sites More sharing options...
djeffers Posted February 27, 2013 Share Posted February 27, 2013 +1 on the accuwedge. It is a cheap solution to get rid of any wobble. Link to comment Share on other sites More sharing options...
atvman400 Posted February 27, 2013 Share Posted February 27, 2013 +2 on the accuwedge. They do help quite a bit when shooting of the bench in terms of accuracy. Link to comment Share on other sites More sharing options...
sludwin Posted March 20, 2013 Share Posted March 20, 2013 i had a ruger sr556 that wa horrible, the fit was so sloppy i could drop a nickel in betweeen the upper and lower.....had horrible groupings. they warrantied it without issue and the new on was much tighter and shot way better Link to comment Share on other sites More sharing options...
lucas Posted March 22, 2013 Share Posted March 22, 2013 Number 8 Oring around the upper front lug from Walmart. Does not put the stress on the rear take down pin hole that the rubber accuwedge has been known to cause. Link to comment Share on other sites More sharing options...
Mark Stephens Posted March 26, 2013 Share Posted March 26, 2013 I guess someone needs to explain to me how a little play between the receivers is going to affect accuracy. The upper receiver, barrel, BCG, optic, and bullet are all locked up together on the upper. As long as the BCG strips a round off of the lower, how is the fit between the two really going to matter? Link to comment Share on other sites More sharing options...
T Bacus Posted March 26, 2013 Share Posted March 26, 2013 A little wobble between the upper and lower is not any problem at all. On the other hand a tight, rattle free fit does 'feel' better. Link to comment Share on other sites More sharing options...
torrpd Posted March 27, 2013 Share Posted March 27, 2013 A little wobble between the upper and lower is not any problem at all. On the other hand a tight, rattle free fit does 'feel' better. +1 Link to comment Share on other sites More sharing options...
dcloudy777 Posted March 27, 2013 Share Posted March 27, 2013 I like the "feel" of a tightly fitted upper-lower too, but it really doesn't matter much as far as performance is concerned. I've shot guns that rattled like maracas that would shoot MOA all day long, and I don't think an upper could have enough "wobble" to hinder feeding without the lugs being broken. Link to comment Share on other sites More sharing options...
Alaskapopo Posted March 27, 2013 Share Posted March 27, 2013 I don't mind them being tight so long as they are not impossible to take apart in the field without tools. Pat Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now