Paul, it will fire mini shells but will likely not properly feed them. The mini shell adapter for the Mossberg should also fit this one, so for reliability I'd use the opsol adapter. Here's a link to one if interested............ budsgunshop.com/product_info.php/products_id/36595/opsol+texas+miniclip+mini-clip+for+mossberg+500+590+12+gauge+1+round+polymer+black+finish......... Hope this helps.

Paul, if you put one in the chamber, it will fire , but mini shells will not will not cycle properly in this gun. The OpSol mini shell adaptor WILL NOT work in this gun. It is for Mossberg's only. Have a great day!

Paul, yes but, it will be hit or miss reliability wise without a mini Shell adapter such as for the Mossberg : budsgunshop.com/product_info.php/products_id/36595/opsol+texas+miniclip+mini-clip+for+mossberg+500+590+12+gauge+1+round+polymer+black+finish