I can't say directly for a 1077 as I do not own one. But I do have a 2300S that was a .177 and was getting 70 shots in the 500 fps range. It has been converted to .22 recently. Now gets 40 shots per cart, on par with a 2240.
Thank you for the reply. I'm only getting like 6 full power shots at about 585fps, then fps drop down quickly. I don't think it's leaking. What could be wrong?