If power or repeat hit speed means nothing to you, why not just use a pellet rifle, hmm? If you read and understand Paladin Press's book, HOW TO MAKE A SILENCER FOR A .22, you will be out only about $40 for your "can", along with the $200 Fed tax, of course, and that includes internally threading your barrel yourself. Once you have made the special, brass- piloted tap drill bit, all you need is to borrow the use of a vise, a level, and a hand held power drill that features a bubble-level built into it. The counterbored hole in the muzzle and the internal thread means that you don't have to remove and relocate your front sight..
I've had a 10-22 Ruger do ok with the 60 gr subsonic Aquila load. You can just use CB caps in a long barrel and it will be fairly quiet. They will take squirrels and rabbits with chest hits.
There is very little noise that escapes the ejection port of a suppressed .22 autoloader. On a very quiet, cold,night, on flat open terrain, you might hear it at 200 yds, but typically it goes unnoticed at 100 yds. In wet, warm conditions, in wooded hills with a bit of wind, it will be unnoticed at 50 yds. Ditto if passing vehicles or dry leaves in a breeze are creating "background noise".
The book shows you how to create a mallet-powered "die-set" for forming the baffles, and it shows you 2 ways to mount the male-threaded adapter into the rear of the can. It may be welded into place, using an $80 MAPP -oxygen torch, or it can have 3 roll pins driven into holes that are drilled thru the side of the tubing (1/8" from the end of the tube, centered on the sides of the bolt head) and into 3 (alternating) sides of the 6 sides of the hex headed bolt that becomes the adapter.
A .238" ID hole is of course drilled thru the 3/4" long bolt, lengthwise and centered. this allows the bullet to pass cleanly thru the adapter. Then JB Weld epoxy seals the holes in and around the pins, and around the sides of the bolt head. A can must be a 'gas tight" container, you know. The only hole in the can must be the one the bullet comes out of.
The formed, annealed, copper screenwire "donut" baffles have a 1/4" ID hole thru their centers, for the same reason as the hole thru the adapter, letting the bullet pass thru them. All .22 cans have to be cleaned every 300 rds or so. The powder residues start to make them "louder". A few shots of brake cleaner solvent and then blasts of compressed air (from a can of air intented for cleaning computer keyboards, if need be) suffice, but let all inflamable vapors evaporate before firing thru the can, or you'll have a fire inside of it.