I have been shooting one for a couple years. I load it with cast bullets going about 1600 fps. Shoots great. It is like a mini 45-70.
You can certainly run hotter loads using the jacket bullets and it would be adequate for most game under 200 yds.
Cruise around Marlin owners, lots of info.
The light weight cast bullet are very fun to shoot and I easily get under 2 inch at 100 yds with a low power scope. Dumped a couple coyote in their tracks. The 375 front end stops things.