.32-20 bore diameter

AJMD429 · Post by **AJMD429** » Thu Feb 28, 2008 8:29 pm

I have a 1980's vintage Marlin .32-20 that slugs .308 on the lands and .313 on the grooves.

What size lead cast would work best for the gun? I see very few bullet molds that throw over .312, at least going by the catalogs.

Next question - I've toyed with the idea of an Encore barrel in .32-20, but they use .308 rifling. What kind of problems would the two different bore diameters cause? Of course in the Encore, I might be using jacketed and pointed bullets, so perhaps the two LOADS would be obviously different; would I have to segregate brass also?

It is a shame such useful cartridges as the .32-20 and 7.62x39 suffer from lack of consistent bore diameters.

Leverdude · Post by **Leverdude** » Thu Feb 28, 2008 8:34 pm

I believe its suposeda be .312

I never slugged mine but it shoots 312 & 313 hard cast very well.

The different bore sizes kinda complicate things if you have them both.
I dont think I'd push a .312 bullet down a .308 bore & I dont think a .308 bullet would work real good in a .312.

RSY · Post by **RSY** » Thu Feb 28, 2008 8:53 pm

Leverdude is right about 0.312". It's the same diameter as the .303 British.

Good luck,
scott

old goat · Post by **old goat** » Thu Feb 28, 2008 9:04 pm

...It doesn't matter what its supposed to be, if it measures .313, then you need a lead bullet of at least .314 or a little more.
...If you can't find an "off the shelf" mould to cast the proper size, then have one of the semi-custom mould makers, make you one.

old goat

Sixgun · Post by **Sixgun** » Thu Feb 28, 2008 9:24 pm

I have 32-20's in a couple of different diameters. Colt Lightning with .311, Marlin at .312, Remington 25 at .312, '92 Winchester at .311 and a couple of pre-war 'Smiths at .312. I size everything to .312. Velocities in the rifles run 1400. The Remington will not shoot with plain base bullets at all so for that one I use the Lyman gas check version, as I do for the '92.

Try you gun first with .313 or if you can't do .313, go with .312. Sometimes things work against conventional wisdom. If that don't work, use a gas check bullet at .312. That will work.-----------Sixgun

JerryB · Post by **JerryB** » Thu Feb 28, 2008 9:25 pm

I don't know about Marlins but my old Winchester 92 slugs .312. Years ago I loaded the Speer .308 100 grain Plinker bullet with Unique and got fine accuracy with it.Try some different loads and see what your rifle will do.