gonna reply to my own post here.
took the gun to the range and it had no problems with 2-3/4 dram 7/8oz, 2-3/4 dram 1 oz, or 3-1/4 dram 1-1/8 oz loads.
it was flawless.
Upon cleaning i did notice some plastic shavings in the fore-end and stuck in the rings on the piston.
looks like the piston is rubbing the bottom inside the for-end.
anyone seen this before?