My Avenger .25 likes the 40 grain Apolo slugs about 1/2" at 25 yards. Only 770 fps though and got my reg and hammer spring just about maxed. Lol still 52 ft/lb of energy though. It shoots the 33 grain Apolo's at 850 fps but did not group as good
For 350 dollhairs you can get an air venturi Avenger .25 cal that will lay the smack down on rodents. Lol. But you'll need a 50 dollhair hand pump from Amazon to pump it up.