Seems this board is a mite slow.... Still, I just completed my "Mk I" and thought I'd post here....
Being an older guy, I started out shooting air guns with the classic Red Ryder BB gun way back in the 50s... Graduated through a variety of BB and pellet guns including a Benjamin .22 Pnuematic that I put thousands of rounds through. I credit that gun with me getting "expert" with the M-14 in basic training back in '64.
I've always liked making and fixing things; I repair and refurbish bicycles, build my own archery equipment, make cigar-box guitars and other instruments...
Decided to give this air gun thing a try.
My first attempt is a simple ball-valve model:
Nothing new to most on the forum, I suppose, but it seems to work quite well. I've been pumping it up to 125 or so with a bike pump and using 1/2" marbles for ammo.
They whiz right through several sheets of drywall...
I didn't care for most of the designs you see on YouTube with the valve on the left side of the gun and the trigger operating on the spring... Too clumsy to set up.
Saw a drawing for this right-side direct trigger arrangement and thought it looked much more efficient.
Still want to do a reciprocating-valve model, and I want to try some .45 cal. lead balls patched.