I ask them to toss in a bit on the ammo, unless it's just .22.
Fullbore, I ask 'em to cover whatever I payed for what they shoot. Their "head tax" for range use? I pick that up.
NS
On their first trip, I pay for everything (transport, ammo, beer afterwards). I always have extra eye and ear protection too.
That's how I was treated, and what goes around comes around. If they insist on paying, I usually tell them to save, pass their PAL, buy guns and ammo, then treat somebody else as I treated them. It's contagious, and good for all of us.