I came across this caliber recently and saw a reloading chart that had a 15 grain moving out at 3750fps using WW296. Apparently case is made from .223 parent case and only about 1 inch long. The load was around 8.0 grains of WW296.

This caliber would make a fun varmint rig for those non windy days and would be awesome to watch the bullet impact.

Could also function as a Carolina whitetail shooter if only headshots are used!!!!!!!!!

Sounds like a shortened & necked down 221 fireball.

The .17 Squirrel is based on the Hornet case shortened. The Hornet case is 1.403 and the Squirrel is just under an inch. With a 20 grain V-Max a .17 Squirrel will basically be a re-loadable .17 HMR with a 3 grain heavier bullet.
Fun little round but a wildcat that commands mucho respect in reloading. Things happen real quick in a case that small.
I was told by a top Cooper tech one time he felt the .17 Squirrel was one of the most dangerous rounds Cooper chambered rifles for. Not really sure about that, to me all of the real small cases deserve a little extra attention but the pay-off in fun factor is well worth the attention to detail. I do know for sure however it's a gas with a pocket full of shells and a field full of gophers .

If a guy wanted to get into a first small .17 caliber wildcat that isn't as labor intensive, caseforming etc. I'd recommend a .17 Ackley Hornet. Moves a 20 grain V-Max right at 3,800FPS and is a dandy varminter out to 300ish yards. This guy ran afoul of that Cooper .17 Ackley Hornet at about 175ish yards as memory serves. One shot, lights out!