I have a Marlin 336 in 38-55. 26" barrel with Ballard rifling. 1:18 twist. Played around with a bunch before I got the C Sharps (38-55).
Today I was in the reloading shop and I noticed I had some cast 310DT tapered bullet. I am the second owner of the Marlin and the first owner apparently had the Marlin "fix) done ("throated"). I can easily chamber a 250gr seated out as far as she can go and not touch the lands. The barrel slugs at a touch over .379 and I have got the groups down to around 1 .75 + at 100 yards. Normally, 2". A bunch of stuff was done to the Marlin per M McPherson's book.
Mounting the 336 in the rifle clamp, I picked up an as cast bullet, and dropped it into the chamber. Then I took a case that I had rigged before that would place the bullet 1/16" in front of the 2.08" case. Some pressure needed when I got to the .379 band but the lever closed and is not bent
Pushing the bullet back out, the lands have made skid marks on all but the base driving band. Will this be a problem? I realize I may get some leading and the hot stuff may screw up the base, but I want to try some.
Drop tube style, OE FFG to the top of the case weighs 50.9 grains. .030 Walters wad and I am good to go.
Is there anything to be concerned about with the base band "hanging out back" other than disappointing accuracy...maybe. I have rigged up a blow tube so I can fire ten rounds without wiping. Heaev forbids it works, duplex here I come.