Hi all this is oldgeorge I just completed a rebuild on a new 1377 it has a 14-in barrel a buck rail muzzle brake and oversized transfer port still has the plastic breech it I ordered a Steel Breech it hasn't arrived yet from Crosman I ran it through the chronograph this morning and with the 8.1gr lead pellets h&n I got 347 ft per second then I switched over to the alloy pellets the 5.1gr and I and got 463.1 fps with 10 pumps both time :-* :) I was happy oldgeorge God bless stay safe and well
Hmmm... If your numbers are correct, you got slightly more energy (in fpe) with the lighter pellet. Normally you'll get more energy (in spite of fewer fps) with the heavier pellet, not the lighter one. Note however that the lighter pellet will lose its energy sooner, due to the slowing effect of wind resistance on the lower ballistic coefficient.