Shooting a double rifle, and especially hunting with one, is awesome. I bought mine in 2004 and quickly learned that it will pretty much force you into reloading if you weren't there already as you basically sight the gun in by adjusting the speed of your bullets. Until going actively into all this, I couldn't imagine that softs and solids can shoot differently, even with the same load, or that crimping or not (I found that you definitely should), would impact the the POA if you're really particularly about things like that. A chronograph eventually becomes your best friend along with Graeme Wright's book. As recommended earlier, accuraterelaoding.com is an awesome resource.

Have fun!