Best .177 / 4.5mm JSB slug pellet
The Mk3 works WAY better than the Mk1, especially in low powered guns, as these Mk3 expands from 500 fps (152m/s) and the Mk1 does that from 700 fps (213m/s).
If you hunt pests at short range and use 10gr Heavies, I would suggest to try these instead. Only Mk3 though. 515 fps mod25 pistol is within 1/2” (~1,25cm) from 6-22 yards (6-20m). And at 20 only lost like 25 fps so caries near same energy of 5.5fpe / 7.5 joule. Worth a try if accurate.






