300 gn TSX 45-70 Distance from lands?

[Dogleg]

They have an enormous hollow point that more than covers the primer pocket of the shell on front......not sure what bullet you folks are seeing

Do you think that the cartridges sit nice and straight in a tube magazine, or do you suppose that they are as crooked a stack as it's possible to get?

My experience with light .458 Barnes bullets is with the .458 Win. Velocities are considerably higher than what you're talking, but as range increased they eventually start thinking they came out of a 45/70. What I saw over and over is that at the lower velocities bullet expansion was considerably reduced, to the point where they weren't much over original diameter. That's with the advantage of smacking thick skinned solid critters, not some pillowy soft spongy little grizzly bear. I'd start with a different bullet.

 

[nof60]

They have an enormous hollow point that more than covers the primer pocket of the shell on front......not sure what bullet you folks are seeing

Just a couple flaws in your theories. If these are the pointed bullets (which were the only 300 gr ones I saw on their site) I would be pretty concerned stacking them in a tube. They don't lay in there straight at all.
Secondly, and most glaringly, looking for sub MOA and then shooting it with a ghost ring seems counter intuitive. Why bother with tack driver accuracy and then shoot it with a ghost ring?
Thirdly by the time you get it load tested enough to get your sub MOA out od a lever action rifle with a short barrel you will either have a broken stock and or scope from your lead sled or such a nasty flinch that you wont hit anything anyway if not using a sled.

You need to understand that these rifles are for close in nasty bush work. I carry mine a lot (I live in Yukon). They are not tack drivers and are not meant to be. they have the trajectory of a rock. The most important thing a bushgun needs to do is function flawlessly every single time. Better to shoot a bear with a gun that shoots a 4" group then beat it to death with a gun that shoots a .5" group.

Pick the Medium Load and load it to the SAAMI OAL. Problem solved.

Also got to beartooth mercantile and order the safety delete kit and throw that stupid crossbolt safety in the bush.

Look for mom, mob, or moe accuracy not sob moa. (Minute of Moose, Minute of Bear and Minute of Elk)

If you want to play the tackdriver game buy a tackdriver not a bushgun.