I saw a post on this Hunting Forum by Hekk187 about shooting Varmint Knocker Slugs in an Edgun R5 Magnum .25 cal. I have one of those R5's so I bought some Varmint Knocker 40 Grain large hollow point slugs like Hekk187 said. Then I tuned my Edgun to shoot them at 870 fps (67 fpe). I then shot a squirrel at 40 yards. The results were devastating. The squirrel was facing me so I aimed at its chest. The slug hit the squirrels right front leg on the way in and totally smashed it. It was hanging by strings. Then the slug traveled through the squirrel's body and struck the squirrel's hind leg breaking it clean in half. I used to have an FX Bobcat .30 that shot 76 fpe and it did not do this type of damage. It would always blow through the squirrel and damage my feeder or tree bark. This Varmint Knocker slug gave up all of its energy inside the squirrel and did not exit the squirrel's body.
This shows the slug expansion.
This shows the slug expansion.