Re: 338-416 Rigby IMP
Jody, I had another gunsmith look over our rifles and found a slew of problems including a large amount of runout on the chambers. So, we decided to have both rifles rechambered for A-Square's 338 Excalibur cartridge. We also chose this cartridge over the 338-416 IMP because we didn't want to go through the hassle of forming brass. Ballistically, the Excalibur is very similar to the 338-416 IMP with the added bonus of having formed brass available. Granted, A-Square's brass for the Excalibur is twice the cost of Norma's 416 Rigby. Sorry, I won't have any information for you. I just received the reamer for the Excalibur and hope to be shooting in a few weeks. As to WC-872, my lot (have 6-8 lb. jugs) is within one grain of the new Hod. US869 powder, very slow. Hope this little bit of info helps in your load development.