lol, i had to reread it to update myself. At a certain pressure, i could still pump easily but was losing air in the stroke( i was no longer building valve pressure) . So my max was whatever i last mentioned ( 560 fps i think, so with a 10 inch barrel that means i was producing 14-1500 psi roughly ) Everything in the pump mechanism needs to fight or abate flex and deformity , and any tolerance gap leads to this " losing air in the stroke" .. I never did narrow it down , i think i messed with it another week or so before scrapping the idea. Looking back now id have used a stiffer main tube , as some of the flexion was happening in the tube itself. I also would have likely used a tiny poppet with 2mm stem , as it became air retaining if im remembering correctly and that wasnt the goal. The pivot pin was another issue , and i had too little wall left to go bigger.. First try at a pumper so a lot of guessing went into this thing.
Hi Ray , i do think theres some potential for a medium power ssp pistol with reasonable pump effort. I kinda switched gears on this build mid way through and went with what materials i had on hand, were i planning ahead and buying ideal materials , id probably have been more successful..( thicker wall tube , thicker pivot pin , etc ) I hope youve seen duane38s msp 9mm , i dont have the link but its on GTA. A 1 inch piston was easy to move with the extended pump arm , so were i ever to try again id likely start at 1.25-1.5 inch diameter piston. id say a 550 fps ssp is possible while staying "pistol size " I also think an open faced valve with spring on the stem side would be ideal.. Who knows maybe one day ill get back to it
accumulating a good crosman parts bin is a must