I picked up several boxes of 300-grain JFP Prvi Partizan 44 Magnum ammunition. Its advertised muzzle velocity is surprisingly high for such bullet weight in a standard length cartridge

My intention is to use this specific ammunition and 6-inch S&W Model 29 for antler elk and black bear hunt, maximum range range with 3X Leupold pistol scope will be less than 100 yards. I am particularly concerned with penetration. Penetration is the reason I selected 300-grain JFP bullets. My thinking is bullet weight emphasizes penetration while jacket and flat point enhance moderate expansion.

Should I expect any unusual issues with this ammunition?

Should the same revolver and ammunition be satisfactory for guided Alaska brown bear hunt?

I am not the biggest revolver expert but my S&W 29-2 doesn't like 300gr bullets at all.
The recoil unlocks the cylinder and apparently it is fairly common with S&W 29s.
Apparently the performance package make them better.

If your revolver likes them they should be just fine

What seems to happen is your shot will kill, but your elk will go to the bottom of the divide to die, not fun..I witnessed this on several instances with a Ruger #1 rifle 45-70 with FP solids and again with soft points. Fortunately in all cases it left a decent blood trail.

Sounds more like a bullet placement problem than just a bullet problem. If those bullets are hard, break both shoulders, if the bullets are soft shoot through the lungs, top of the heart. If you can't get those shots don't shoot.

Dick

They were lung shots.

A steady diet of 300 gr. bullets can be hard on the older 29's, that's why S&W made the later upgrade. Better off to get a Ruger bisley, some like the Blackhawk but most prefer a bisley for the heavy loads.
If bullet placement is correct you won't have to track the animal, regardless of size, just do your part & the bullet should do the rest. Long tracking means poor shooting.