I'm not much on shooting indoors so I'm not at all up to date on what's going on with indoor ranges. A lot of outfits used to build up target butts out of uncoated Celotex. But that has been a while back. Don't know what the material of choice is now.

Our club went from Celotex butts to Morrell Eternity bag targets on our outdoor range and we've been very pleased with them. Not much way of sticking paper targets on them though.

Good luck on getting the club going!