Receiver Fitting

[10Driver]

I purchased an Anderson slick side upper receiver to mount on an Anderson lower for a dedicated.22lr clone build of a CMMG Banshee. For now, I have every intention of just leaving them together as an assembly and do not plan to swap either receiver around to any other build.

The issue I’m having is the Anderson slick side upper is very loose on the Anderson lower. Additionally, I’ve tried that slick side on another 6 or 8 (Aero, Anderson, and PSA) receivers, and it’s loose on every one. All my other uppers (Aero and PSA) are very tight on all of those same lowers. The slick side Anderson is the only loose one and it’s consistently loose on everything I have.



I only know one other person who assembles ARs and he says the looseness and rattling isn’t uncommon and shouldn’t be a problem.



It’s for a 4.5” dedicated .22 pistol, so is it an issue and will it affect functionality, accuracy or long term durability of the build?

[ozleux]

No, it's not uncommon at all. A couple of things you can do is, drill and tap for a tension screw at the rear pin. Or, you can get some shims to eliminate the side to side play. I just got a set from Triggershims.com, and took care of the same issue in a recent build.

[Boolit_Head]

I use a accushim

http://www.wheeldiamond.com/ar15accushim.htm

[ozleux]

I use a accushim

http://www.wheeldiamond.com/ar15accushim.htm

That looks like a better option.

[golfindia]

The $2.99 option

https://www.midwayusa.com/product/10034 ... edge-ar-15

"Improves accuracy" :^) put two of them in!

[Boolit_Head]

The $2.99 option

https://www.midwayusa.com/product/10034 ... edge-ar-15

"Improves accuracy" :^) put two of them in!

I hate those, when they get old they can crumble and get into the trigger.

[g22rmr]

The $2.99 option

https://www.midwayusa.com/product/10034 ... edge-ar-15

"Improves accuracy" :^) put two of them in!

I hate those, when they get old they can crumble and get into the trigger.

I've had a couple kicking around for something like a decade, I just checked them and they are still as soft and pliable as the day I got them. I don't use them anymore because I swap all my lowers until there's no play whatsoever and sell off the loose lowers. Lowers are cheap after all, and swapping parts on them is stupidly simple.

[Boolit_Head]

The $2.99 option

https://www.midwayusa.com/product/10034 ... edge-ar-15

"Improves accuracy" :^) put two of them in!

I hate those, when they get old they can crumble and get into the trigger.

I've had a couple kicking around for something like a decade, I just checked them and they are still as soft and pliable as the day I got them. I don't use them anymore because I swap all my lowers until there's no play whatsoever and sell off the loose lowers. Lowers are cheap after all, and swapping parts on them is stupidly simple.

Maybe they changed their formulation but I tried one back in the 90's and it crumbled after about a year in my patrol rifle. I'm sure sitting in the trunk of the car in every sort of weather from -20 to 100+ every day did not help.

[10Driver]

Anderson said to use a wedge. Not excited about using one if the the looseness isn’t a function or accuracy issue.

If it’s not an issue, then I’ll ignore it.



FWIW, out of 8 lowers, this specific upper is loose on all 8. None of my other uppers are loose on any of those 8 lowers. I’m guessing here, but I’m thinking it’s the new upper and not the lowers.