I will have to find or take some more pictures.
I use a .25 Benjamin marauder on 3200 psi with modified valve, hammer/hammer spring and air stripper. Shoots 26 grn pellets just over 900 fps very accurately with the " quiet/accurate tune" 43 grain d ellets at 870fps on full power.
There's some crosman2250 pistols I modified with steel breaches, bigger vaelves anchored thru the action. One is converted for scuba air too.
My home brew was a crosman pump pistol I made pump/ or pre charged for a while and now it runs exclusively on 2k feed from a mounted 4500 psi paintball tank. I get so Many shots I only take the tank to be filled at the local paintball store 3 times a year.
The compressed air "Pcp" guns are great if you live near somewhere to fill you up, otherwise its an expensive hand pump, lots of exercise and servicing the o rings in a crazy 3200 psi pump.
I will find some pix later.