there is a big difference in both the 44 cal & the 45 cal first the diameter is .022 difference & second is the 44 -240 cal has a bc of .205 & the 45 cal xtp mag has a .180 bc . the 44 cal flies flatter. i"m not sure who it was on this site really recommends the 44 xtp over the 45 xtp mag they claim it has more knock down power. i myself use the hornady 45 cal 300 regular xtp & it has the bc of .180 . used to use the 45 cal 300 xtp mag & a mmp sabot that was getting a .210 bc . the the xtp mags were getting hard to find due to a lot of handgun reloaders are using them with a hot load. i"ve read alot of stories were the hunter a killed a boat load of deer/ hogs & etc with the .44- 240 xtp"s. i myself have switched over to the hornady 350 grain fpb bullets just due to the blood trail it leaves ( one that stevie wonder could follow ) but mainly because of most deer drt. also to save your friendship have him call hornady personally to have them set him straight & maybe save him from a accident waiting to happen