I'm going to be using my Marlin 44mag lever gun to hunt whitetails with this year. I'm planning on using the Hornady 240gr XTP and W296/H110. I'm not looking for barrel burning speeds but speeds good enough for the bullet to do it's job and for it to be accurate.
So educated me on my next steps

Put 23-25gr of powder in the cases, and use magnum primers. Standard large pistol primers can struggle to ignite the ball powder in the cold, so I stick with magnums (after missing an opportunity at an elk due to a squib in the very cold). I found charges right at the top end to work the best for accuracy and low velocity variation. I like CCI250's and Starline brass, but Winchester and Remington and Federal have worked about the same, though they each have slightly different capacities.

Shoot 23, 23.5, 24, 24.5, and if everything looks okay so far, 25 grains of 110/296. Pick the load that shoots the best. The speed will be between 1600 and 1800 fps. The bullets will kill as far as you can hit, to at least 300 yards.

My Marlin is pretty loose as far as chamber and bore dimensions, so I've never had a problem stoking it up. Some older data I've seen goes beyond 25 grains, and some newer data I've seen stops at 24 grains for 240 grain bullets. I've always topped out at 25 with the 240's, and that's were the XTP's shot best for me. Noslers shot best at 24 grains. Old Federal JFP shot best at 25 grains. Put a good roll crimp on 'em, but don't buckle the cases attempting too much of a crimp.

Good info! I do have a box of Nosler 240gr HPs I picked up for a bargin of 29.99 for 250. I wasn't sure if the on game performance of them and have been told repeatedly to use the XTPs. I have a few 180gr XTPs but believe the 240 is a better choice

I use only one load in my Marlin 1894S. The 270 grain Speer GDSP bullet over 21 grains of H110 powder. Winchester Magnum large pistol primers.
In my rifle, I show 1600 FPS. 50 yard target shows a cloverleaf. At 100 yards, it groups around an inch and a half.
This load kills large hogs, and Whitetails grave yard dead.

I used LilGun with good results in my Win92 trapper and my Ruger 44 Carbine. Sadly both rifles are gone. I like the Nosler JHP bullets and had good luck with them in 44 mag as well as 444.

The Noslers kill well, and open a bit wider than the XTP's, at least according to my sample of two kills and one recovered bullet. Weight retention was good in the one recovered 5 inches into the frozen ground after going through a deer at a slight quartering angle. Exactly 180 grains for 75% retention, and a big, wide mushroom.

I'd recommend the Speer Deep Curl/ Gold Dot over the XTP. I used the 240 grain Deep Curl HP last year out of a 22" single shot.
This year I'm using the 210 Gold Dot out of an 1894 SBL 16 1/2" barrel. Accuracy is exceptional.

Only a sampling of one, but I killed a fairly decent rag horn bull elk a few years ago with a Marlin 94 in 44 mag. 240gr XTP and loaded with the load data on the jug with H110. It was about 50yards and the elk dropped on the spot. About the same as a bull I killed with a 45-70and 405 gr bullet a few years before that.

I would not go wasting my time trying to find some super duper bullet when what you have will more than do the job on a 150 pound whitetail if it will kill a 500 pound elk

I always used Winchester Large Pistol primers. Marked on the box "For Magnum and Standard Loads"

I have two Rossi .44 Mags. Let me just say any good 240gr SP or JHP will do in any deer made.

Yes the XTP is a fine bullet and 296 will do. You don't even need max charge. Accuracy is the key cause the .44 has plenty of power.

The 44 mag has been the iconic revolver magnum, but it is another animal in a rifle. I’ve found even a moderate 44 mag load like Win white box 240-gr loads gains 500 fps in my ‘94’s 20” tube (~ 1750 fps) over a 4” revolver barrel. I’ve found another (factory 240-grs) that will go over 1900 fps.

You will not be lacking with the XTP’s or any stouter bullet for use on white tails.