17 HM2 is the best cartridge for squirrel hunting I've ever used.
I would find what ammo it prefers then lay in a big supply when possible, then you are set for a long time for hunting.
The few I've owned have been as accurate as a similar 22lr with match ammo as well.
Agreed, 17HM2 is the best tree squirrel hunting cartridge yet to be introduced.
I've shot fox squirrels at 100+/- yards when they were eating waste corn in harvested fields. Sneak along the edge of the field, see a squirrel, sit down, extend the bi-pod legs, take aim, squeeze the trigger, dead squirrel. Repeat.
None of my 17HM2s will shoot the 15.5 grain NTX worth a damn, but they shoot most lots of 17 grain Hornady/CCI pretty well, but none shoot as good as the long discontinued Eley or Elay-made Remington. Eley 17HM2 ammo was match grade accurate for about the same price as mid-grade Eley .22 LR ammo. It was a sad day for 17HM2 shooters when Eley stopped making it.