Martini 310 Cadet Rifle Reloading

[6mmintl]

Martini 310 Cadet Rifle Reloading

I recently picked up a 310 cadet rifle with a very nice bore and had to replace the custom Mahogany butt and forestock with originals; barrel marked 32-20 and bore measured .3235 (8mm)

My chamber measures .359" at base and .344" at a trimmed cartidge length of 1.060".

I looked at various bullets and bullet molds for reloading and decided on:

1. Is a total copper plated lead bullet from Buffalo Arms for the 8mm Lebel pistol, ($.12 each) weighting 100 grains and has a .330 diameter, .546 long, and .245 long bearing surface. I resize this thru a standard 8mm (.323) lee sizer/luber sizer kit ($25.00) or you can have Lee make a custom sized sizer die to fit your bore for $30.00. 100 grain total copper plated bullet has an overall length of 1.345", diameter over loaded case neck is .341 with a chamber diameter of .343

2. Is a 152 grain cast bullet made from a Lee two cavity .329 diameter 205 grain weight gas check bullet mold (C329-205-1R for Stery 95) for $35.00. 150 grain bullet overall length measures 1.620"", Diameter over loaded case neck is also .341 with a chamber diameter of .343. I shortened this mold .300 and it cast a 151 grain (1/30) bullet .797 long with a .320 diameter nose/bore riding diameter and a .242 long bearing surface, I then resized them to .323/4" diameter.

I Lee Liquid Alox pan lube # 2 and it shows the most promise for longer range shooting accuracy (100 yards 1.5" and no traces of keyholing.

I am driving the 100 grain bullet with 9 grains of A2400 and 8 grains of A2400for the 150 grain bullet and have had zero leading.


For dies I ignored the standard 32-20 dies as they size brass undersize and settled on 32 ACP dies, I run a 8mm Mauser die expander ball down to bottom of case and expand cartridge base and decap primer, I then size 1/4" length of the case mouth with a 32 ACP die and then seat 100 or 150 grain ..323/4" Dia bullets with the 32 ACP seater die without crimping.

I tried the 120 grain heeled bullet and did not have as good accuracy as with the 150 grain bullets (1" at 50 yards with two powders/loads tried, still experimenting with powders and charge weights).

You have to keep in mind that the original Cadet chamber is a progressive cone (22RF heeled bullet style) then straight diameter (bullet throat relief) to the rifling.

[Fjold]

The thing about a lot of those old guns is that they are fun to play with but the variations in chamber and bore dimensions makes developing loads a challenge.

[6079Winston]

My .310 Cadet oddysey began with a .32-20 marked gun with a worn bore and factory .32-20 ammo. Accuracy was poor, so I decided to line the barrel and purchased a liner and reamer. A few months later I picked up a minty .310 marked take off barrel at a gun show for $40 and decided to try that instead. I reamed the minty take off barrel to accept the thicker rim of the .32-20 case and swapped it onto the gun. I cast 20-1 alloy bullets from an RCBS .310 Cadet mould and trimmed .32-20 brass until a seated bullet would just barely chamber and then trimmed .020" more off to allow for bullet jump and easy chambering of lubed ammo. The .32-20 cases were charged with 8.5gr of 2400 and the loaded ammo was dipped in melted SPG up to the case mouth. Accuracy was good with no leading, although the load is not regulated to the original sights. If I ever feel like it I might work up a load that jibes with the sights, possibly using black powder or a substitute If I decide I want to spend time cleaning brass. For some reason this rifle really makes me want to shoot either rabbits or prairie chickens with it. Rabbits would probably be more appropriate considering the kangaroo on the receiver.

[smle-man]

You guys have done a lot of work to reload for your cadets. Being the lazy type that I am I shoot .32 SW long cartridges in mine. Mine is still in the original .310 cadet chamber. The .32 soft lead bullet upsets in the bore and provides excellent accuracy at 50 yds. The cases bulge a bit but so far none have split. The round nose bullets seem to do best and the target wadcutters the worst. I bought a bunch of Aguila .32 ammo from AIM and have been working my way through it. The report from the rifle is less than a .22 lr probably because the bullet isn't supersonic when it leaves the muzzle.