I wasn't impressed with the 250gr either when shooting full power loads into media. They turned into thin pancakes. It may perform quite well on deer as the fps falls at longer ranges. The HP is huge compared to the 44/240gr or the 45/300gr.

Ive only shot the Speer .475 275gr and it held together fine even at SML speeds. Im considering trying the .458 350gr in the 52cal. It should be a real hammer at nearly 2000fps. I should be able to get close to 2100fps with the 325gr in the 52cal. IIRC that is about the fps i got from a 325gr FTX with a stout load of BH209.