My MKIV 22/45 with a JPoint on it. I've closed up the ports on the brake twice but never ran a patch down the barrel. Shooting CCI SV (which it really doesn't like) Blazer, Mini Mags, Federal bulk pack, Remington sub sonic (I know), Eley 10x, Winchester Power points and Winchester high velocity stuff among a few other brands that I'm forgettng. I do have Hogue grips on it now.
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I'd send it back and never try the TB's in the new barrel.