Here is a example.I'm 220# not 200 but close enough. No world champion boxer up to a 150# can knock me out and he has speed on his side.Now I feel there is a fair chance that a champ at 175 will at least put me down and 180# put me out though both will have a slower punch.In a round about way its what TKO is all about.A 200#der would be hard pressed to knock out Klitschko.
Then, by your example, since the 300gr XTP failed to TKO the original poster's deer................do we need to use a 400gr bullet instead?
A few seasons ago, I shot a whitetail doe with a 500gr RNSP from a .458 Win Mag at about 50 yards. The doe jumped in the air, turned, and ran approximately 50 yards with a hand size exit hole in her ribs and insides hanging out. The bullet bisected the lungs and exited in front of the diaphragm on the off side. However, the temporary cavity created by suck a mastic hydrostatic shock, ruptured the diaphragm and shredded the liver. Being as the liver is not a pliable organ (like the lungs) and highly susceptible to tearing. A .458 Win Mag...........with a 500 gr bullet and she ran.
Conversely, about 20-30 minutes prior to that, I'd shot a doe with a .375 Ruger and a 270gr Spire Point bullet. She was quartering to me at maybe 100 ish yards. At the shot, she crumpled to the ground. That bullet struck the point of the shoulder and passed just below the spine. The impact of hitting bone and the disruption of the nervous system by the hydrostatic shock caused instant incapacitation and unconsciousness. She died of her wounds before regaining consciousness.
I'll go ahead and say it. It's not what you use for the most part. It's where you put it. Weight does not equate to less tracking just because it weighs more. If a 500gr .458cal bullet from a .458 Win Mag does not drop a whitetail doe, you cannot emphatically say that a 300gr XTP from a .44/.45 caliber handgun will drop a deer any better than a 240gr bullet from the same gun.
It might........it might not.
I dropped a boar pushing close to 300 pounds a couple months ago with one shot of an 85gr 6mm bullet from a 6x45 cartridge at around 200 yards. One shot, he hit the ground squealing. A bullet through the spine.
Ain't what you use, it's where you put it.
But, even that is not an absolute. Without proper penetration, the rest is moot.
Heavier weight does not equate to less tracking in and of itself. It can assuredly help because of the increased penetration it may provide. But, just because it's heavier, does not mean it will. There are too many other factors and variables to consider.
Of all the good reasons to suggest and recommend a heavy for caliber bullet, less tracking is not a realistic one in my opinion. Not when there are more viable reasons to suggest it.
Again, this is in NO WAY presented to be demeaning or spitefully argumentative. It's a discussion. We all have opinions and views. Experiences and thoughts. I'm just sharing mine and enjoy reading others.