Which Nielsen slug .

I have no decent group with JSB Knock out,

H&N or any nielson slugs. I'm on sandbags and groups at 5 or 6 inches🤨

Cheap crosman hollow point ammo at low per can stack at 35. Turn up the pwr a little and all seem to be decent.

The power is really good for 21 to 25 grn and will reach out to 100 but the energy is lost with pellets so I am going to try a homemade air stripper.