When I first began hunting deer with a handgun I young and uneducated in the importance of penetration. I chose a 180 grain HP of no longer remembered manufacture, loaded them into my 8 inch barreled model 29 and had at it. On the second day I shot a nice 8 point buck square in the shoulder at 25 yards, and promptly watched him get up and leave. Light blood trail lasted about 200 yards before fading away to nothing. Hard lesson learned. I educated myself about proper handgun hunting ammunition for deer, and switched to 240 grain Keith semi wadcutters, then to 250 grain Winchester Partition Gold when it became available, then to 240 grain Hornady XTP's when I couldn't find the 250 gr Nosler partitions to handload. Since that first lost deer, I've shot near 20 deer with .44 magnum handguns and rifles, and have not lost another. I can't remember any of them going much more than 75 yards before piling up.
Last Friday evening I shot a mature doe at 25 yards with my Marlin 1894 carbine. It was loaded with 240 gr Hornady XTP's over 19.5 gr of 2400. The bullet struck the deer behind the right lower shoulder, opened a 50 cent size entry wound into the chest cavity, breaking several ribs on the entry side. It then plowed a channel across the top of the heart, then exited through the off side shoulder, breaking the shoulder on the way out. When I rolled the doe onto her back there was that sloshing sound you hear after liquifying a coyotes innards with a .22-250. This has been the usual performance I get from the 240 gr XTP. Did I mention I really like the .44 Magnum as a deer cartridge?