BudsGunShop.com - shell size?

YES! It will RUN 2 3/4. Capacity of 5+1 with 2 3/4-inch shells. The only thing it wouldn't eat was Aguila mini shells. I hope this helps!

Stephen, this shotgun has a 3 inch chamber and will run shorter shells like 2.75 no issues. The mini-shells do not have enough powder/velocity to reliably cycle though. Cheers and stay safe!

Stephen, this gun is chambered in 3 inch, so yes it will take 2 3/4" shells, however it will not cycle the mini shells.

The 1301 Tactical is offered in 12 gauge only at this point and features a 3 inch chamber. In a small, lightweight shotgun like this one, you really don't want to shoot 3 ½ inch shells anyway - it's not intended to be a turkey hunting gun.
Above is a quote directly from berreta usa website.
So yes it will run 3" and shorter.