Re: Supressor for 9mm hand gun and Remy 308
While possible in theory, it really isn't practical.
First, you have to find a suppressor that threaded inserts that can be changed or use thread adaptors (700 SD uses 5/8x24 RH while the USP 9 uses M13.5 x 1 LH threads).
Then you have the fact you are hanging a giant 308 suppressor on the end of a handgun. Not only will it be unwieldly, but your USP will not cycle with a suppressor on it that does not have a LID/booster/nielson device on it.
Really the wait time shouldn't factor into a decision whether to get a 9mm or 308 can. Either you have enough money to buy both now, or just buy which ever one you think you will use more first and just buy the second one as funds allow.