I can't speak to accuracy as I haven't used the Hornady 265 gr bullets in my 96/44 but from what I understand they were designed for the .444 Marlin (at 2400 FPS MV) and don't expand much at .44 Magnum velocities, even from a carbine. A tough bullet that probably penetrates a lot like a hardcast at say 1800 FPS or slower. Just a thought.

I know most guys who use heavier than 240 gr bullets in .44 Magnum prefer the faster 1:20 rifling to stabilize them, so theoretically at least you should be accurate with the right loads. In my case I actually use lighter bullets but the monometals are long for caliber so I think the faster twist still helps.