even cheap ones worked great in mine, so good ones should work really good.
This barrel has worked great, and increased my a5's accuracy and apperance. dosen't do much for the loudness, but it never said it would. VERY good barrel for 40 bucks! There are some horrible things out there in the "under $50" range, but this isn't one of them!
If you are using ANY stock barrel, go get this barrel now! It will help, i promise. I wouldn't waste my money if I already had a more expensive one. nobody needs a collection of barrels. i give it a nine cause its awesome, but i still want a boomstick!