Milsurp After Hours

I can not seem to find the chamber dimensions for the 310 Martini Cadet rifle in any of my many reloading manuals or from an online search either. I have owned one for many years and just love the beautiful little thing. It has had a 32 20 chamber reamer run in it offcenter (probably by a drunk or nitwit or both) and I would like to set the barrel back and rechamber it to the original dimensions if I can find the information. Any help would be greatly appreciated.

I don't have access to the CIP specs for the round - your best bet would be to make a chamber cast from an unaltered rifle, and more or less duplicate the configuration - it might even be possible without a reamer, I presume the chamber is completely cylindrical with just a bevel for the rifling... Don't forget to take into account the heeled bullet though when determining chamber length, as a portion of it has the same diameter as the case...

Dont know if this helps.

TRY THESE PEOPLE THEY MAKE MOLDS FOR THE 310 CADET THEY MAY BE ABLE TO GIVE YOU CHAMBER DIMENSIONS.

TRY SEARCHING THEY HAVE A WEB SITE.

CAST BULLET ENGINEERING Bullet Moulds

Name: CAST BULLET ENGINEERING

Email Address: JIM.CBE@Bigpond.com.au

Street Address: P.O. BOX 269

MENAI CENTRAL

N.S.W. 2234

AUSTRALIA

Phone Number: 02 9532 0103 (OVERSEAS 61 2 9532 0103)

Fax Number: 02 9532 0103 (OVERSEAS 61 2 9532 0103)



JIM.CBE@Bigpond.com.au © 2006 CAST BULLET ENGINEERING Bullet Moulds

Thank You for the quick reply. I was looking for the diameters of the case mouth (O.D.) and just in front of the base (wondering if there was any taper ) and also the O.A.Length plus the Diameter and thickness of the base. Thanks in advance if you have this info.

Nominal case dimensions I can provide you when I'm back home, chamber dimensions, that's something else...

Anyway, when you have to make a chamber, it would be best to spec the case mouth OD based on the groove diameter of your specific barrel. I think you will need to take into account an expansion/ contraction of around 0.02",and also check with the heel dia. of the bullet you intend to use, as well as brass neck thickness - in order to avoid 'conflicts' like not being able to insert rounds in the chamber...

I've just miked up some fired cases, these are Buffalo arms reworks on 32-20 brass.

Case diameter just ahead of the rim .348".

Case Diameter at the mouth .337".

Rim diameter .404"

These cases chamber easily and I don't resize them at all.

case mouth ID: .316

ahead of rim OD: 0.320"

ahead of rim ID: 0.316"

base,front of rim: 0.353"

length 1.020"

Just bear in mind the bore dimensions of these rifles vary considerably... If I were you, I would dimension the base to the brass you will use (Like .32-20)

OK Thanks a lot guys. I think I have made up my mind to rebarrel and chamber to 32-20. In the long haul it just makes more sense to me. Again Thanks to all of you who spent time getting the info.

310 cadet is also a very nice cartridge, very accurate too. And above all, different! I once played with the idea to make myself a converted BSA12/15 in .310 cadet, to check out the (considerable) accuracy potential of the round.

FWIW, I also have a 12/15 converted to 30-20 (.308 barrel) - I used a surplus Schultz & Larsen match barrel (from a rebarreled full-bore match rifle) and the original peep sights. That rifle really is a tackdriver - makes look even my shooting good!