On one RRA lower, the upper is side to side wobbly with three different uppers. I heard of a wedge that tightens things. Is the wedge available and worthwhile?

I’ve never used one, but it seems cheap enough to give it a try and find out for yourself.

https://www.midwayusa.com/product/100340833

The “Accu-Wedge” (or whatever it’s called) has been around for a long time, and I’ve used them off and on for many years. The claim is that they improve an AR’s precision, and although I have no proof of that because I’ve never conducted any side by side tests with and without, I always think of the old joke about giving chicken soup to the dead guy: “Could it hurt?”

I also found that my Wilson Combat model Protector S rifle came from the factory with something similar, a rubbery insert in the lower receiver that the upper presses against when they’re assembled. The WC is quite accurate for that type of rifle and I must believe that if the company goes to the trouble of including the feature, it must be for some reason.

One thing I do know is that the Accu-Wedge puts pressure against the upper and if nothing else probably reduces movement wear between the upper and lower. And of course they’re practically free, so why not?

I use the Accuwedge on some of my ARs. If your receiver is a high-shelf, an Accuwedge will not fit- no room for it. My Rock River Arms lower is a high-shelf.

Otherwise, on ARs that have more play than I care to tolerate, I'll put in one of these little gadgets. If the fit is too tight, the Accuwedge can be trimmed easily. I've had to do this on a couple.

Does this gadget increase accuracy, as the name suggests? I'd be surprised if it did. All it does is remove wobble. At one time, Colt sold the Accuwedge- for something like four times the cost of the plain old Accuwedge, which was exactly the same part.

I've used the wedge as well. Sometimes you might have to adjust/cut the wedge height to get the proper fit but that is no problem as they are made of rubber.

Related aside. I recently picked up an Aero lower for a project gun, and was surprised to see 2 holes in the grip area.

Upon further investigation, it seems that Aero took the idea of the Accuwedge and incorporated it into their lowers. There's a special rubber tipped grub screw in there whose entire purpose is to put pressure on the back takedown lug of the upper receiver to reduce/remove receiver play. Obviously you'd need to tune this to your upper.

Does the wobble affect function, accuracy, precision of upper?

Are we talking a little bit of wobble or can you physically see a shift in your sights/optic?

Every manufacturer is different in their tolerances. Some are tighter, some aren’t. If you get multiple manufacturers who are on the “looser” end of specs, this is what you’ll experience.

Honestly, if it isn’t affecting the above things, I wouldn’t worry about it.

quote:

Originally posted by Hamden106:
On one RRA lower, the upper is side to side wobbly with three different uppers. I heard of a wedge that tightens things. Is the wedge available and worthwhile?

Don't hedge, does the wedge give accuracy an edge as the sellers allege, or is that a false pledge?

I put an eccentric front pin on one of my ARs to tighten it up.

Yes I’ve used the wedge. Another thing you can do is put all or part of a foam earplug under there, or a suitable cut of compressible material.

Now days I’m more likely to make my own than use an accu-wedge.

Accuracy issues aside, I don’t like excessive wobble.

Never tried it myself, but I've heard that some people put an o-ring around the rear lug to take up the slop.

electrical tape on the lower where it closes at the front or rear or the lower deck is an old school cure,

but honestly, why worry until you shoot it,
it is does what it is supposed to do, then move one and enjoy

Acu-wedge works great. They also sell shims for the front, they work but are a pain to deal with it you take your rifle apart alot. There's the "o-ring trick" you can use up front as well. I've used the opposing/expanding rear pin that... JP maybe? makes/made. Works well, but another pain as you need tools to take the gun apart. I've also peened the lugs on uppers to tighten the fit a few times, but you might not want to do that.

The wobble shouldn't effect accuracy at all, or at least to any real life noticeable amount, but it drives me crazy and that's much worse.

I have quite a few somewhere in my workbench. Email me and I will send you some to try.

I’ve always used the JP Enterprise eccentric pin … it’s a two piece pin that pulls the upper & lower together rather than push them apart like the wedge. The down side it that it requires a small wrench to tighten it up.

quote:

Originally posted by RichardC:
Don't hedge, does the wedge give accuracy an edge as the sellers allege, or is that a false pledge?

That is a hard no on needing a wrench to disassemble an AR.

I bought some stripped lowers years ago that had a set screw inset into that low shelf with a rubberized tip. You would put the upper and lower together and then screw it in till they were at your preferred snugness.

My new LWRC came with that set screw hole but no set screw. They used an accuwedge type device with a molded pin that fits in that screw hole. Fancy accuwedge.

Wobble is a non-issue. Just shoot it.

quote:

Originally posted by JoshNC:
Wobble is a non-issue. Just shoot it.

I am in this camp. One thing that drives me nuts about the accu-wedge is it maximizes the gap between the two receivers. Being able to see through the gun like that irks me. The wobble and the sliver of light are both things you only notice in administrative handling. If you're using the gun, you won't notice either, IME. If we're splitting hairs, you could argue the slop accelerates wear of the lugs, as previously mentioned, or that the propped-open gap acts as an ingress for debris. My sloppiest gun is coincidentally the one I shoot the most. It is a former LE gun, with unknown round count and abuse history. It is no sloppier than some guns you see on the gun store shelves, so the wear is probably not a huge concern.

I don't like stuff flopping around.
An o-ring around the front lug works ok.
Lowers with the adjuster works well.

One of mine flopped like a rag doll.
I was going to try the JP oversize pins. https://jprifles.com/buy.php?item=JPTDP-223-SET
But I had a PSA take down pin that was way over sized so I turned it down till it slid in.
Pin slides in and out easy and it locks up solid.

Take down pin removal.