Bumps the power up a lot, but with it recoil, air consumption and noise all go way up. I use mine for hunting so it’s not a big deal. With a port and polish, •Stock spring 187ft lbs 110grain .357 dbhp. ~125 psi a shot, 2850psi fill

•Heavy spring, transfer port removed,3 turns out from full power

230+ ft lbs 110grain dbhp ~ 150psi shot

3200psi fill

I have not messed with the heavy ammo yet but should perform even better. Standard deviation and spread also increases so it “strings” a bit more. The de-pinger was a game changer though,I highly recommend that. The mega moderator has a thwack sound, and only added a few inches to the overall length. Donnie sound is more of a ping, I wouldn’t shoot this with out a suppressor. All in I’m happy! increased power, flatter trajectory, shorter oal with mega moderator, much more comfortable to the ear, very accurate with nsa .357 110grain dishbase hp.