Hi thanks for replies I took trigger unit off my other hw77 and made sure tab at rear were exactly the same would this make gun hard to cock cause have to really yank back with cocking leaver just to cock the thing sear dose not engage if I don’t I have watch the trigger while trying to cock gun and nothing happens in the trigger unit unless I really yank back on underleaver safety dose sometimes engage depending on how hard I pull leaver back cleaned out trigger with solvent spray then regreased yes think it is older model my other hw77 is totally different to cock thanks