Oky the home-built Bosvark by Johan, this air rifle is huge fun, kicks like a mule.
297cc pressure vessel - Fill pressure 300bar - 24in barrel 1:17 twist (so 34gr should still group but the heavies is just for power )
First up 18gr 5.5mm JSB full power, kind of disappointing, but seems we need a longer barrel .
Then we did a 34gr 5.5mm JSB pellet, better, but the Bosvark wants more
And then for the heavies, 55gr 5.5mm own cast, YEH that's more like it