I picked up my new 257 Roberts Mauser 98 from the FFL this past Friday. After I did the transfer, I looked over in the ammo grab bag. What a coincidence, it was loaded with 257 Roberts brass and ammo. I was able to buy all 82 pieces of brass and 38 loaded rounds for a measly $20. A Black Friday miracle! I did notice some of the ammo was labeled +p. Anyone have experience loading to these levels or replicating the performance safely by handloading?