Proper cast bullet for .310 Martini Cadets (RCBS 310-120-RN)

[ohland]

http://fmgpublications.ipaperus.com/FMGPublications/GUNS/GUNS1111/GetPDF.ashx

"Surplus Locker", Holt Bodison, Guns Magazine, Nov 2011, pages 30-33.
The Elegant .310 Martini Cadet

"It took one of my hunting partners, Bud Bristow, who also owned a lovely Martini Cadet in the original .310 chambering which he used for pursuing javelina, to remind me years later that RCBS had introduced a mould for the heeled .310 Greener bullet (mold 310-120-RN). Bristow had also verified the accuracy of a handload developed by Ross Seyfried consisting of 4.2 grains of Hodgdon Universal Clays powder. The RCBS bullet cast fairly hard lubricated with Lee Liquid Alox and seated over a sol wax wad. So far, it is the load for either the .310 Greener or the .32-20/.310 Greener and generates a velocity of 1,200 to 1,220 fps. At 50 yards, it will cut 1-1/4" to 1-1/2" for four or five shots if the cast bullets are uniform. "

:coffeecom

[curator]

Good article! Anyone considering gearing up to shoot the Martini .310 Cadet should slug their bore first. Groove diameters range from .318 up to .323+. The RCBS mold I have for the .310 drops bullets at .319" cast from WW alloy +2% tin. Both my Cadet rifles measure .321 in the grooves and lead like crazy with the RCBS slug. The heeled design of the bullet precludes the possibility of bumping it up to size. I bought a .323 diameter mold from CBE in Australia which drops beautiful 120 grain bullets at .323 just like it claims. Problem solved! Loaded to a velocity of 1220 fps (4.5 grains of Unique) the gun shoots true to the sights out to 300 yards which is the longest I have to shoot here about.

[Outpost75]

I have had much better results with softer, 1:40 tin/lead alloy from Roto Metals, loading 3 grains of Bullseye, which shoots to the sight graduations out to 300 yards using the RCBS bullet, as- cast and unsized, witb Lee Liquid Alox. Ten-shot groups are 2 to 2-1/2" at 100 yards, and in proportion at 200.

[Bad Ass Wallace]

It would seem that someone found ALL the Martini Cadets in Australia with oversized bores and send them to the USA?? I have 11 in my collection and only one manufactured by Greener has an oversized bore of .321".

The introduction of the heeled boolit was due to these Greeners, however, 10 of my BSA manufactured rifles have bores of .316 and using a conventional non-heeled bullet sized to .317 gives very good accuracy. We even had a local supplier who made 120gn jacketed boolits of .316 dia but has since retired.

http://img.photobucket.com/albums/v152/BAWallace/IMG_2478_zps854c0f3b.jpg (http://smg.photobucket.com/user/BAWallace/media/IMG_2478_zps854c0f3b.jpg.html)

BTW, They are lovely little guns when fitted with a bayonet!

http://img.photobucket.com/albums/v152/BAWallace/Engarde.jpg (http://smg.photobucket.com/user/BAWallace/media/Engarde.jpg.html)

[ohland]

BTW, They are lovely little guns when fitted with a bayonet!

Reminds me of the defense of Rorke's Drift. Get a platoon of good bayonet men...

Supposedly, Cast Bullet Engineering has about 6 good boolits for the 310. I see no list of them, and wading through the images of the boolits does not identify them yet. :coffeecom

http://www.castbulletengineering.com/

http://www.castbulletengineering.com/page0031.html
.310 MARTINI CADET

This popular single shot rifle has a bore size of .310” and a groove diameter of .316” to .318”. Similar in size to the Winchester 32-20 , the .310 Cadet was originally loaded with a Full Metal Jacket projectile as required for Military use and a swaged lead projectile for target work. The cartridge/rifle combination was found to be very accurate and was popular in the early 1900’s as a “Miniature Target Rifle”. Large numbers were shipped to Australia as training rifles for Cadets and in WW2 they were provided for use by Home Guard defences in the event of an invasion by Japanese Forces.

Experience has shown that heeled projectiles with diameters from .318” to .323” give best results as the gently tapered throat on these barrels actually measures around .325” in front of the case mouth. Chamber castings show there is no step in the chamber . Barrels we have examined show a smooth polished leade ideal for cast bullets. Case thickness varies between original and modern manufactured brass and most modern cases will not chamber with projectiles having a heel much larger than bore size (.310”) and in some brass the heel needs to be even smaller.

C.B.E. offer the widest variety of projectile designs available anywhere for this caliber. In the photo below on the top left is a .310 case loaded with our most popular design # 320-120. Beside the cartridge on the right is a fired projectile recovered from the mound . Note that the heeled section ( just visible between the lube groove and the rear) has expanded and is fully engraved by the rifling. The heel was .310” before firing and expanded to fill the .318” groove diameter. Smaller diameter heels will also upset provided the alloy is not too hard. The more the heel has to upset the more effect it can have on accuracy so bigger is better in this situation. Illustrations Available

[curator]

******Wallace,

We always suspected you Aussies kept the good ones for your selves. Most folks on this side of the world can't measure a bore slug with and odd number of grooves/lands. It takes a special "V" micrometer with a 72 degree anvil (although you can "punt" with a more common 60 degree) So, measurements are mostly guestimates. We once had a generous old-timer engineer named MacKeagen who had all the necessary measurement devises to measure 3-groove Springfields and all manner of 5-groove Enfieldian rifling slugs. He could give both bore and groove down to the ten-thousandth. My two Cadets both measure .3104 (bore) and .3210 grooves but had a .323 "throat" right in front of the case mouth. I sent several slugs from Friends" Cadets and some were smaller like yours, and some were even larger than mine. It appears some tolerance was allowed on Cadet bores by the manufacturers. Nonetheless, once figured out, what great shooting rifles! I use mine to teach beginning shooters who are joining our JrNRA Olympic rifle teams. They love the fact that the rifles are 100 years old and still shoot accurately.

[Bad Ass Wallace]

Reminds me of the defense of Rorke's Drift. Get a platoon of good bayonet men...

Different uniform:razz::razz:

http://img.photobucket.com/albums/v152/BAWallace/PvtWiddle.jpg (http://smg.photobucket.com/user/BAWallace/media/PvtWiddle.jpg.html)

When you think about it, a plain based projectile is going to shoot better than anything else. The heeled boolit is to me like shooting any rifle boolit without a gas check. At the point of exiting the muzzle that gas is going to be trying to squeeze past the heel!

I use a CBE boolit catalogue number 317.125 PB

[ohland]

What are all the CBE boolits for the .310?

Colour Sergeant Bourne!

Well, at least your tunic is buttoned up...

http://en.wikipedia.org/wiki/Frank_Bourne

[dromia]

I had Tom at Accurate moulds cut me a 310 Cadet heeled boolit mould based on the GB we did few years ago, I had the heel cut to be a snug hand fit in Kynoch cases with a soft range scrap alloy. It is a catalogue item now, this is my go to Cadet boolit.

[ohland]

I had Tom at Accurate moulds cut me a 310 Cadet heeled boolit mould based on the GB we did few years ago, I had the heel cut to be a snug hand fit in Kynoch cases with a soft range scrap alloy. It is a catalogue item now, this is my go to Cadet boolit.

Praytell, what is the catalog number?

:coffeecom

[dromia]

http://www.accuratemolds.com/bullet_detail.php?bullet=32-120C-D.png