Hornady SST 20 Gauge Slug

A: Lee, yes Sir but, it will not be nearly as accurate as this was designed for a Fully Rifled Barrel.

A: Lee, Yes it can be fired with rifled choke if that is your only option.

A: Do you have a good brace on your Mossberg shockwave? If not and you are planning to shoot off-hand, then probably not. You might injure yourself from recoil throwing the gun around. That being said, this is not as bad as some 3" 12ga slug so if you can hold down the shotgun well, it will be manageable....but not fun at all. I hope this helps

A: Jose, I have shot these in 12ga without issue. Recoil was stout but manageable. You just need to pay heed to a firm two hand grasp on the Shockwave. You will get the hang of it quickly and wonder what all the fuss was about. Cheers and stay safe!