bulletbob7,
I've had a 444 Marlin since way back in the mid 1970's. Simply put, I love it. I took my first deer with it using factory 240 grain soft points. It was a broadside shot and put a heck of a hole going in and out. I began loading 265 grain Hornady flat points way back then and I haven't used anything else since.
My pet load is 51.0 grains of IMR 3031 and CCI 200 primers. Please be advised that my loads are for MY gun and I do not guarantee them for use in anything else. Use at your own risk. I found this load very quickly in the development process so I didn't have to look any further, and I've never switched to anything else since. The accuracy is supurb.
There have been two wild boar also taken with the Hornady bullet and load. The first was a medium sized boar, a Blue-Boar that I got in North Carolina. One shot quartering away at 75 yards put him on the ground so fast, as if the props had been knocked out from underneath him. The bullet entered near the ribs on the left side and exited out the neck on the opposite side. The second boar was a large black one that my son took in Tennessee. The dogs had it at bay. I have that one on video and the actual shot. The boar spun around about a half turn, staggered for about three seconds and then fell. That was it. The bullet did not exit on this one, but put him down quick.
When I bought this gun, I thought perhaps it might hit a milk jug at 100 yards. To my surprise, it is more accurate than a lot of varmint rifles. The gun will, for the most part, shoot under 1" at 100 yards with my above load, and believe it or not, one time I actually shot three shots touching each other at 100 yards. I loaned it to a friend one time to deer hunt with, and he said he could consistently hit beer bottles with it at over 100 yards. He and another friend has tried to buy it from me for years and I won't sell it.
My experience is limited to the above accounts with the 444, but for me, I wouldn't hesitate to hunt deer, hog, bear or anything else of similar size at moderate range with that cartridge and bullet. It's a thumper and a stopper.
Hope this helps.
Good Shooting
My son's Boar, shot at about 30 yards,
one-shot kill with a 444 Marlin and
265 gr. Hornady Flat Point bullet
Record Book tusks