My buddy has a 444 Marlin and about 600 rd of Hornady ammo with the 265 FTX bullet. We have been “emptying” the factory brass so that I can load some 240 gr LRNFP bullets using IMR4198. Several books list that powder as some of the best for that cartridge, using that bullet. The problem is, the Hornady cases are shortened (by Hornady!) to 2.065”, down from the normal trim to length (TTL) of 2.215”
The 40 cases that I have prepped are at 2.077, or .138” shorter than the normal TTL. That makes our cases 93.7% (a 6.3% reduction) volume of a normal TTL case at 2.215”. For that 265 gr bullet, Hornady lists 36.6 gr – 41.9 gr IMR4198. I plan to pull one of the factory rounds to measure bullet seating depth compared to what will need to be done with the 240 gr LRNFP bullet. The two Lyman books I have are showing starting loads of 28.0 gr (50th edition) and 32.5 gr (Cast Bullet book) for the same 240 gr LRNFP bullet. The charge of 28 gr is a 23.5% reduction of 4198 and the charge of 32.5 gr is a reduction of roughly 12% from that listed for the FTX bullet. All being starting loads for that powder. I called both Hornady and Hodgdon and was told that I cannot load that 240 gr bullet in the shortened cases. It seems that with a 25 gr lighter bullet, and a 12% to 23% lower charge, the load I want to create would be safe. That is, assuming the 240 bullet seats to no more than, and possibly less than, the depth of the 265 gr FTX bullet. Does anyone have access to one of those subscribe to, load calculator programs, that could run some numbers? What do you all think?
Thanks!

__________________
Thugs that comply don’t die!