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TheClap1
04-27-2010, 3:12 PM
Is it normal to have a slight wiggle in the lock up between the upper and lower receiver? or is it suppose to be tight?

rct442
04-27-2010, 3:13 PM
This is your best friend:

http://www.brownells.com/userdocs/skus/p_993150100_1.jpg

djleisure
04-27-2010, 3:14 PM
A slight wiggle is pretty normal. If it really bothers you (or is more than "slight") just throw in an Accuwedge.

http://www.cactustactical.com/osc/accu-wedge-for-ar15-rifles-p-131.html

http://www.brownells.com/userdocs/skus/p_993150100_1.jpg

TheClap1
04-27-2010, 3:22 PM
it's a slight wiggle, it's not that bad but it does bug me. I did see that accuwedge and was considering it. thanks guys!

ninjamaster
04-27-2010, 3:24 PM
Milspec tolerances leave a slight "loose" fit. Sometimes parts are out of spec and this leaves you with either more wiggle or a tight fit. I built an AR with a no name upper and an Olympic lower that were so tight I had to use a punch to move the rear take down pin in and out. I used that rifle for many years without problems. It felt really nice not having a "wiggle" either!

rct442
04-27-2010, 3:27 PM
it's a slight wiggle, it's not that bad but it does bug me. I did see that accuwedge and was considering it. thanks guys!

All you have to do is trim it to fit. I took a old razor blade, and sliced off layer after layer from the bottom until I could barely push in the pivot pin. Now there is no wiggle between the upper/lower.

http://www.fullam.com/images/tools/526601.jpg

tacticalcity
04-27-2010, 3:31 PM
Sadly, there is no way to predict how snugly an upper and lower will fit. Buying from the same brand will not help. Mixing and matching specific brands will not help. Sometimes you get lucky and get a super snug fit, most of the time you do not. I have noticed Model 1 Sales uppers tend to be extremely loose no matter what lower you put them on, all other brands tend to be pretty darn close and are fixable with an accuwedge. Overtime, as you tilt or remove your upper and put it back on a bunch of times, it will loosen up as well. So keeping some spare accuwedges laying around is always a good idea.

-hanko
04-27-2010, 3:38 PM
A slight wiggle is pretty normal. If it really bothers you (or is more than "slight") just throw in an Accuwedge.
Or easier, pull the pink eraser out of a regular yellow wooden pencil.;)

-hanko

djleisure
04-27-2010, 3:41 PM
Or easier, pull the pink eraser out of a regular yellow wooden pencil.;)

-hanko
Even better!

Omega13device
04-27-2010, 4:59 PM
A little wiggle is normal and doesn't affect accuracy, reliability or anything else. The extra room is there so that if both the upper and lower are on the larger end of their manufacturing tolerances they'll still fit together. It's what makes all uppers and lowers interchangeable.

So learn to love the wiggle. :) I do not recommend using the accuwedge in an otherwise functional rifle. Incidentally "accuwedge" is a misleading name because it does nothing for accuracy. It should be called the "OCD wedge".

Other normal things you shouldn't worry about include brass marks on the brass deflector, the "sproing" noise you hear with A2 stocks, and the color of your upper and lower not matching.

djleisure
04-27-2010, 5:07 PM
Other normal things you shouldn't worry about include brass marks on the brass deflector, the "sproing" noise you hear with A2 stocks, and the color of your upper and lower not matching.
Nice pre-emptive strike! Agreed!

KING_PALM
04-27-2010, 5:10 PM
Or easier, pull the pink eraser out of a regular yellow wooden pencil.;)

-hanko

speak more about this!!

CHS
04-27-2010, 5:10 PM
Incidentally "accuwedge" is a misleading name because it does nothing for accuracy. It should be called the "OCD wedge".


HAHAHAHA.. OCD Wedge. I'm stealing that :)


Other normal things you shouldn't worry about include brass marks on the brass deflector, the "sproing" noise you hear with A2 stocks, and the color of your upper and lower not matching.

Quoted for TRUTH.

How OCD people get about AR15's is laughable.

killshot44
04-27-2010, 9:54 PM
Actually, play between the Upper and Lower CAN contribute to accuracy problems. Bad enough to have the moving mass of the BCG in semiautos but a shaky Upper is not a good thing.