First, cut the stock barrel just behind the AR, you will need at least 3/4" of the original barrel. Also, beveling the inside edge of the barrel helps with inserting barrels.
Then, get your materials: Tape(thin is best), PETG (~.572 OD) and wrap the end of the PETG until you like the fit in the barrel stub.
It should look similar to this.
Now put your blaster to good use.
Edit: Im sure someone has thought of this before, but I've never seen it documented, so Im just making sure it does.
Edited by Aimless, 16 August 2008 - 12:58 AM.