The microgroove barrel has 12 lands/grooves IRCC. The Ballard has 6grooves. Not hard to tell the difference.
The biggest difference is with cast bullets. With the MG barrels, you'll need to size the bullets a tad bigger. ie: .461" vs .459".
Besides that, no real significant difference.
I've had both. I much prefer my current one, but it is an 1895GuideGun without the muzzle ports. I specifically wanted one without the ports.
Be careful about Marlins. They inflict a disease call "Marlinitis".
Just "One", becomes not enough. I've got a mild case. I now own just five:
A Mod-39D, a Glenfield M30 (plain wood mod336) in .30/30, a Mod336A in .35Rem, a .338MX, and the .45/70.
The .45/70 gets shot the least, however. My "favorite" is the .338. However, the .35 has killed the most deer, as it is the "luckiest" of the clan. Then of course the .22 gets shot the most, for obvious reason.....
BTW; only the .22 has "open sights". The .45/70 wears a Williams "Guide" reciever sight and "firesight" front blade. The rest have scopes. I can't bring myself to "hobble" the accuracy of these "shooters".
BTW; an 1895 made after ~1994 will not have the two screw holes on the left side for mounting a reciever sight. However, Williams makes both the "Guide" Reciever sight that uses the rear two scope mounting holes, and they make a specific version of the 5D and "Sourdough" that mount to the rear scope mount holes. Just need to be sure to order the correct one. Or, have a gunsmith drill and tap the reciever. Marlin before 2008 would do this just for shipping it to them, but now that they have been bought out by "Freedom Group", I don't believe they have the time or willingness to do so.........