The hop seems to be adjusting itself.
the cup seal on the nozzle seems to be causing excessive drag on the nozzle (yes properly lubricated)
occasionally an extra BB will just roll out of the barrel.
it is a toxicant spear, so MWS, but short bolt system. The first day I had it, it ran amasing, but the second day I fielded it I started getting issues with the hop and extra BBs falling out
Edit. The whole replica is stock, the only parts added were the barrel and bucking as the Toxicant don't supply these with the RIF.