9MM to 45 see ******* Specifications and Features:
Birchwood Casey Handgun Dueling Tree Target
*********For 9mm to .45ACP handguns
No tools required to assemble
6 shooting paddles
Includes hard molded carry case
AR500 steel paddles

Good morning Jacob, this dueling tree is made for handgun calibers 9mm to 45Aacp.
Stay safe & have a great day!

I like putting my dueling tree out!!
These are rated for 9mm-45 acp. And yes, I've shot it with .22lr and there was not enough energy there to flip them. They are thick steel & it's a heavy unit.

Hi Jacob and welcome. 9mm through 45ACP so .38 Special also will properly activate the targets. Cheers and stay safe!

Jacob, this is designed for 9mm to 45acp. You can use smaller calibers like 22lr but they likely won't have enough energy to spin the target. Hope this helps.