I tried Accuwedges but they never fit right and found them frustrating to retrofit. I tried O-Rings around the front lug but that never worked either cause they'd always snap or severe.
The final answer was simply cutting a foam earplug in half and placing it under the rear lug. It snugs it just enough to keep the wobble at zero, but allows the take down pin to move in and out without too much resistance. IMHO it's the best solution I've found or discovered in the last 6 years.
I have a Bushmaster & Stag that both have foam earplugs in them. My RRA is tighter than the gates of hell.
To cut the foam earplug in half, you can do it easily by putting it in the freezer for a few minutes then cut it with a box cutter or razor knife. Then, let it thaw, and simply toss it in the lower reciever under the rear lug. It does a good job "expanding" to fill the voids between the lug and the reciever. It's also durable enough to withstand years of use.