I ordered a spacer from Hansohn Brothers. A lot cheaper than the $89 fixed mount that is out of stock everywhereNice. I have one in jail since last May. I'll have to keep a close eye on the piston. I have been shopping for the fixed mount or fixed barrel spacer so I can use it on my PCC's. They have been out of stock forever. Those seem like they would be pretty easy to make and keep in stock.