Defo check the TP.

Also check the piston is round and true, and the rod is central.

Check the rear guide when fitted lines up with the trigger block hole (I mean exactly).

Check for burrs on the underside of the cocking slot

Check the cylinder is even as you slowly push the piston down

Check the barrel lock up stop is allowing a proper breach seal closure (true face, not sloping up or down).

Check it's not over sprung.. a 80/R1 should cock really easily if making just 16 FP in .22