Slugged my Marlin 357 CB

[crabo]

Well, as far as I can tell my lands and grooves were .346 and .356. I really had a problem reading my dial caliphers. Does this sound about right? I have the Ballard rifling in this gun.

I tried some LBT push through slugs and ended up using a pure lead swc. Do you think bullets sized 358 will be too large for this barrel? How will I know?

I only have a 3565 and 358 and 359 dies.

Thanks,

Crabo

[Nrut]

Crabo..Take a fired case (one that was loaded with a high pressure load) and see if a .358 cast boolit will fit in the neck...I am betting it does...That means that there is enough room in your chamber to allow the case to release the boolit upon firing... Next make a dummy round with that boolit and see if it will chamber "and" fit your throat....I would also try a .359 sized boolit since you have that die and a .3565 sized boolit...Which size is best? ...Well start out at the lower end of your loading data and work up loads with different sized boolits(starting with the smaller dia. boolit)to see which load and boolit size gives you the best accuracy...
:)

[lastmanout]

I had the best accuracy with .359" with my WW alloy and lower Cowboy Action velocity (1100-1400 FPS 24" barrel).

[Jon K]

crabo,

Was that muzzle, or chamber ennd that you slugged?
Slug the chamber end, it's usually bigger.

Jon

[crabo]

I slugged it from the muzzle. It was a lot tighter at the muzzle end than it was at the chamber end. Big difference.

I'll try it from the chamber end and just go in about 12"

Crabo

[Jon K]

crabo,

slug it just enough to size the sllug, then knock it back out. That will give you full groove diameter, which is what you're after to make the boolits to fit the gun.

Jon

[crabo]

Thanks

[KCSO]

I never slugged a Marlin, but I slapped the butt of my Winchester once...

Most of the Marlin 357's run right at 357 but don't worry about thhe 356 reading. Load some 358's and try them and i'll bet you willl be just fine.