cast 38-55
 

I had the 336 pre-side safety Marlin/Ron Smith re-bore out today and am pleased with a 1" 3 shot group at 100 yards with Jet Bullets 273gr FN GC .379 Starline long brass /Fed LRP/32gr IMR3031 Hoping to baptize it on a cow moose and or mule deer....... tags pending this fall.I'll bring the chrony next trip out.Due to age /eyesight 4x Leupold used.

I shoot the same bullet and star line long brass with 24 gr 4198 from my 93 marlin it shoots pretty good, better than most of my other cast attempts. The gas check makes it way better

Good chit to hear bud

Your almost as good as me getting bullets and guns to group tight.

Keep up the good work , powder dry and your pencil stiff

Here's the secret
 

I find if I shoot one shot groups they are even tighter!

Was the 336 a 30-30 before and it was rebored out to 38-55?

the 38-55 is a great old round. They are very effective on game and tremendously accurate considering most come in levers. The 38-55 cartridge was often made up into single shot target rifles for serious competitions. The 30-30 was originally made from a necked down 38-55 case so if you have trouble finding brass it is easy to just neck up 30-30 brass.

Good shooting, cast bullets work great at 38-55 velocities.

It was a 30-30
 

Not a collectable waffle top but rather an early 50's pre-side safety half mag 20" carbine already D+T so it's wearing a 4x Leupold.No action work required just the re-bore.I went 1-16" with a .376 groove so either .375 or .377 jacketed can be used as well as the .379 cast I'm running.

38-55
 

Loads chronied today at 1619 fps got my antlerless moose,antlerless mule deer and antlered mule deer.Looks good for this year so far.

That is lots fast enough for thumping moose and the like. Most of the 45-0, 375 Win and 38-55 loads I shoot run right in the 1600- 1900 range and I can tell you they knock stuff down real well. I have shot them faster but I can see absolutely no difference in killing power, they just kick a bunch harder, especially in the 45-70. Second shot recovery is much better at 1700 fps but I have rarely needed the second shot. What kind of groups were you getting out of those loads, or it is the same batch that was giving you the one inch groups from your first post?

Yes
 

Same load 32gr /IMR 3031/273gn FNGC Starline long brass and Fed LRP .379 Jet bullets out of Wetaskawin.It appears to be from the 375296 Lyman mold which in HP should weigh about 265gr but the solids are heavier and the alloy varies of course.