minor issue

[rasman35]

just finished my AR build today and i noticed a little bit of slop between the upper and lower reciever...is this common??? is there something i can do to fix it?

what oil/grease would you recommend for the AR's?

 

[wirehand]

Re: minor issue

The reciever rattle is common depending on the combo that is being used.

Accu wedge
This litle jobber can solve it.

Alot of people use Mobil 1 for lube.

 

[sardiniagunner]

Re: minor issue

A little white lithium grease on the buffer spring kills the sproing sound and sliks things up a bit.

Slip 2000 is an excelent lube that I use onmy ars. most folks recomend you run them a little wet. Just a little on all of the bearing surfaces. Clp wipes for all exterior steel to keep rust away.

JP makes a tensioning pin to remove your slop, but wont help accuracy. The slop wont hurt anything, but heres a link to the pin.

http://www.jprifles.com/1.5.1.7_small_tp.php

Hows about a pic of the rifle?

 

[LUNCHBOX0621]

Re: minor issue

Totally normal to have some rattle and I would just leave it as is. I wouldn't use the accuwedge.

 

[stmcelroy]

Re: minor issue

Normal to have rattle. The worst gun I have owned was a complete LMT upper and lower that I pieced together.

 

[N2DADARK]

Re: minor issue

Any time we qual. I take a little piece of cardboard the wedge it out of the way of the bolt and in between the upper and lower. But accu wedge I hear works longer lol.

 

[salmonaxe]

Re: minor issue

Tight upper to lower fit doesn't have any real benefit. But, I like it when my upper to lower fit is tight purely for a better overall feel.

Oring around the front lug tightens up the fit really well. I make my own from old bike tire. Hole punch then cut into a doughnut. This way when they get destroyed you don't have to buy a new oring.

I really don't see why so many people give all sorts of random advice on lube. I use Breakfree CLP. It's the recommended lube for AR-15's. I've run AR's with no malfunctions on only one cleaning and lubing with CLP for 2k rounds. People think that CLP doesn't work because it "dries up". Just because it's dry, doesn't mean it's not there. When using CLP, what carbon that does build up will build up with the texture of greasepaint, but not harden. I swear that CLP's effect on carbon is what makes it work so well. Only place it does harden is in the impingement area behind the bolt where gasses are directed. This area is under too high of pressure and heat for any lube to stay in place. Luckily this area is also designed with large clearances so carbon has to build up for a very long time before any ill effects are noted. I've also put upward of 500rds suppressed on AR's with only one lubing of CLP with no ill effects.

I apply an even coat of CLP to the components of my bolt carrier group using a toothbrush.

I've seen AR's fail when someone chose some random lube. I suggest CLP and then I've seen the rifles function perfectly. Back when I was a newb I tried all sorts of shit, and some lubes seemed to attract carbon and allow it to build up hard which eventually caused the rifle to fail.

Here in the northwest my AR's get wet. If it's humid, moisture will bead up on or inside hot components. I never see any rust appear on these AR's. Of course if the rifle has been fully drenched, I will use WD-40 to displace the water. Then I'll blow out the WD-40 with my air compressor and wipe off. Finally, I'll re-lube with CLP.

Oh yeah, and I really do shoot my AR's. Depending on ammo costs, I will shoot between 5k-8k of 5.56 a year. Of course I only shoot quality factory ammo or my own reloads. Also my AR's are assembled from the best quality parts. I think some people will claim the failing of a lube when it really is a failing of the rifle. Poor quality parts causing incorrect timing, etc.

 

[Rovieairto]

Re: minor issue

I only use lube if my AR will get wet.
All my (AR's) run just fine dry.

Many lubes will create a greasy sludge when combined with propellant residue.
My rifles run fine with this sludge, and will continue to run great until the sludge dries.
Don't let it dry, it wipes off easily when wet, reapply if needed.
CLP works great.
Keep lube out of the buffer tube, run it dry, or with a light coat of CLP.
The spring twang sound is your rifle talking to you, don't drown it out with lube.
When the twang stops you know your bolt is locked back, when it sounds different you can immediately know what happened (that comes with experience).
I've seen malfunctions from incorrect lube use (especially when cold).
I have yet to see a rifle malfunction from being dry.

Soon someone will come along and tell you something completely different.

Upper to lower fit is not very important for the rifle's inherent accuracy but it does help the shooter feed tiny inputs into the rifle through the grip.
A tiny input would be </= 1/100th of a degree of manipulation, on two separate axis, plus rifle cant of around 1 degree or less.
You can feed those tiny inputs through a sloppy fit but it is easier for me when the rifle manipulates as one solid piece.

I like a tight fit for a precision AR.

 

[KM375]

Re: minor issue

I dont mind the movement unless its my SPR or a National Match Rifle. Then I would get a paired upper/ lower combo with no slop to build on.
I dont like CLP, its supposed to clean, lube, preserve. I clean with cleaner, lube with Miltec 1/slip 2000 and preserve with Birchwood Casey Barricade.