KWA USP barrel, need help

[Ron!n]

I bought a G&G threaded outer barrel for my usp compact and I cant get it to cooperate with the inner barrel. The pin that's supposed to hold the inner barrel in place inside the outer barrel doesnt seem to be doing the job. The inner barrel keeps getting jarred loose and I cant keep it secure.

I know this is common problem with this G&G barrel but I haven't heard a definitive answer on how to fix it. Has anybody had any success installing this barrel on their usp???