Though I think there are better options for a long gun home defense weapon, I also think there are far more
worse options, than an 1894. If the only firearm I had to defend my home was my 1894 .44 Magnum, I wouldn't feel under-gunned at all. But you can bet I would train very heavily with it.
Here is a list of the upgrades I have made to my standard blued 1894 with 20" ballard barrel:
• XS ghost ring sights - you get a longer sights radius, and much faster target acquisition than the stock sights. Just make sure you go through their test post instructions before you install the front sight. I didn't and ended up needing a taller front post. I ended up filing down the base of the rear, to get it as low as possible to compensate. I haven't sighted it in since, however, so I don't know if that did the trick.
• XS lever scout rail - Easy install, and gives you MUCH more optics mounting options. I have a Bushnell Trophy Red Dot mounted in low-profile rings ready to go on it once I have sighted in the irons. I think a red dot would be a great addition if it is going to be a HD gun.
• Wild West Guns trigger - This was a very worthwhile purchase. Not only does it eliminate the annoying Marlin trigger flop, it does lighten the trigger pull and has a crisp clean break. Pretty easy install as well.
• Wild West Guns 1-piece ejector - My stock ejector worked fine, but I like the idea of the beafier 1-piece WW unit.
• Wild West Guns aluminum magazine follower - The stock orange plastic one was easy to scratch, dent, and chip.
• Paracord-wrapped lever - This was the cheapest and best modification I think I've ever done to a firearm. My knuckles were taking a beating trying to work the lever quickly. This takes all the pain out of it.
• Re-shape the extractor spring and claw - as it came from the factory, case rims were not getting behind the extractor upon being lifted and pushed into the chamber. It was causing major feeding issues. After modification, case rims were getting behind the extractor claw every time. But this alone didn't fix the famous Marlin feeding problem with wide meplats or SWC bullets. For that, see below:
• Modify carrier - I had to grind down enough metal on the front upper side of the carrier, to allow rounds to sit just a little bit lower and feed straighter into the chamber. These 2 modifications (the extractor and the carrier) completely fixed all feeding issues 100%. My rifle now feeds all jacketed bullets, as well as HCLFN and SWC bullets equally, like butter. Here is a link to a thread I started on the subject, and my processes:
http://www.thehighroad.org/showthread.php?t=701165
• Remove checkering and width from stocks - Not only did the front and rear stocks on my gun not match at all, the front was way to wide for me. I like a nice trim front stock like on my pre-64 Winchester 94. So I sanded and sanded until I was satisfied, then stained and oiled them. The gun looks and feels 10 times better.
After all these upgrades and modifications, I finally like my 1894. The QC issues at Marlin over the last several years have been heavily discussed here and other places. My gun was no different and took a lot of time and work to get it to run right and shoot straight.
I'll agree with others that the lightest hollowpoint load you can find would probably be best in a .44 Magnum rifle for HD. If it were me, I'd handload some 180-grain XTPs to speeds just fast enough to reliably expand, but not over penetrate. I'd also look into a rail section to add near or replace the barrel band - to mount a light. A mounted, single-level, rugged light on a HD long gun is a 100% necessity, IMO.
Finally, a wood stock lever gun doesn't get a second glance from the gun grabbers, the way an AR-15 or short barreled pump shotgun do. Plus, it can do double-duty during deer hunting season.