Here is a little trick I use to make the upper and lower in my AR fit better, Its almost like glass bedding for those of you who shoot Milsup rifles.
You will need the following:
* 1/4" Wooden dowel
* Mold Release. (Silicon spray might work, but dont use it and come cyring to me becasuse you can't seperate your recievers)
* Acetone or brake cleaner
* JB Weld or metal epoxy
Step 1 - Strip the lower reciever of all fire control parts, remove the rear take down pin, dont just pull it out, remove it completly even the plunger and spring. Remove the reciever extension, buffer retaining spring and pin.
Step 2 - trim the wooden dowel to fit in the rear takedown pin and lug, usually .250" on mil spec rifles.
Step 3 - clean the upper and lower reciever areas near the lower take down pin with acetone or brake cleaner and wipe clean with a dry cloth or rag. MAKE SURE YOU WEAR GLOVES OR BE CAREFUL NOT TO TOUCH THE AREA YOU JUST CLEANED.
Step 4 - If your epoxy needs to be mixed you can do this now.
Step 5 -Spray the Mold release on the upper reciever and the pivot pin lug on the UPPER reciever only, THIS IS IMPORTANT! AND ALSO ON THE WOODEN DOWEL, LET IT SOAK INTO THE DOWL IF YOU HAVE TO. IT might also help to put some on the top edge of the lower where the 2 hlafs meet.
Step 6 - Take a SMALL DAB of epoxy on the end of a pencil (an unused portion of the dowel will work) and place it on the rear end of the lower reciever, just below the take down pin hole and along the rear twoards the reciever extension, but DO NOT go up into the threads, or anywhere near the reciever extension.
(The epoxy will fill out durring the next step so you can see while you do not need alot of epoxy to do this)
Step 7 - pin the upper to the lower by using the front takedown pin, now SLOWLY push the rear end of the upper into the lower, (now is a good time to double check that you applied mold release to the upper)
Step 8 - If you put enough epoxy on the lower some should seep through the gap between the reciever halfs, this is fine, just not too much, just wipe it off with a rag, make sure no epoxy has made its way into the reciever extension, sear pin hole, safety hole, etc.
Step 9 - Now take the wooden dowel and slide it into the rear take down pin hole throught both recievers just like you would with its metal counterpart.
Step 10 - Let sit over night to cure, eat dinner, look at ar15.com, go out, have sex, becasue you can't do anything untill the next morning.
Step 11 - disassemble the reciever halfs like you normally would, you might need to tap the recievers with a rubber mallet to break free any thing that stuck.
Now, when you take everythign apart you should have a custom fitted epoxy bedded reciver.
Just clean it off with acetone and replace all the parts you took off in step 1, and you're reready to go.
How is this better then an AccuWedge? Well, by doing it this way its custom fitted epoxy bedding, and is cheap if not free if you already have the supplies.
This may not work for everybody, but it did wonders for my accuracy and reciever rattle.
Edited bekauze I kan't Spell
I applaude your ingenuity but I think I'd rather just spend $2 on an Accu-Wedge and be done with it [:)]
I'll stick with the accuwedge too, but that’s an interesting way of making a permanent one. I once had an upper that had a LOT of side-to-side play that the accuwedge just wouldn’t fix. I drilled a small hole in the rear take-down pin block of the upper receiver, threaded it and inserted an allen-head set screw. I could back the screw in or out to adjust the fit between the receivers.
Thinking about what you did. You basically bedded the action, which has been done to accurize long guns for many years now. I have done it to several and have always been amazed at the difference it makes. But, by bedding the action, I think you are taking away one of the finer points of owning an AR style rifle. That is, upper interchangability. I believe that by bedding your action, you will not be able to easily fit another upper in its place without removing some of the bedding material, which defeats the original intent. Let us know if this bedding has become a problem in swapping out uppers.