I've been using my 17M2 for tree squirrels for a couple weeks now. While there was one specimen with a spectacular wound - 1/2 the head gone - I have to chalk it up as a fluke. Other head shots have produce wounds similar to a 22LR. Body shots do seem to be a little more destructive but not so much so as to avoid them as with the HMR. When body shots are all that's available I do go for the ribs to avoid meat loss but then I do the same with a .22
I finally recovered a bullet yesterday. Hit the squirrel a bit low, right under the front leg. It traveled the length of the body destroying virtually every organ, lodging in the hip joint. The bomes of the hip were totally smashed but most of the meat was not hurt.
The bullet that began at 17gr. weighed 12gr. A loss of approx. 30% with core and jacket still attached. Not bad at all.
I've found it to be a neat little squirrel rifle but not holding anything over the .22LR at typical woods distances. One thing I have noticed though is that the higher pitched crack of the M2 doesn't seem to scare game as much as the .22LR. I've killed several squirrels that barely moved after being missed with the first shot. Another plus is that I've yet to shoot one more than once. Over the years I've seen a few shot with LR's need a finishing shot but then I've only shot about ten so far with the M2.
Anyone have different experiences?

Ive posted this here before but,I think its relavant

diet coke cans full of water@ 50 ft.one hm2 one 22lr hollow points.By the way,my 10 year old has shot 1/2" 5 shot groups at 100 yds with this,HIS rifle,a cz 452 american.He likes it because of the mild report.

If you go over to rimfire central, they have a trajectory chart comparing the 17 HM2 and 17 HMR. IIRC, the 17 HM2 and 17 HMR have the same trajectory out to about 100 yards. So, if you can keep your 17 HM2 shooting inside 100 yards, you can get flat trajectory and hard hits for about 1/2 the cost of 17 HMR ammo.

Jeff

I have had shots go right thru squirrels at less than 20 yards.

All I've found at 20 yds are fur scraps

It's happened twice and both times with Hornady ammo, bullet goes clean thru the body, the squirrles made it into their holes only to die inside. very odd.