Here is a link to the non-elite Optima shotgun. http://www.cva.com/products/rifle_optshot.htm

Note it says using the same reciever as the optima rifle, not pro. It also lists barrels that can be bought seperately. This could have been a typo but I have also asked the question of BPIbefore and was told the PRO barrels will fit the standard Optima reciever. Check with them directly and verify for yourself.