.310 Cadet Load

A few years ago I was lucky enough to find a Cadet rifle in the original .310 caliber. It's sat in the corner of the gun room all this time until today, when I took it out and test fired it with a load I derived from various references.

The gun was very pleasing to shoot, and accurate.

Here's some of the steps I took:

1. I obtained a number of new 32/20 Starline brass cases

2. Next I bought from Buffalo Arms a supply of 120 grain, 20-1 Alloy, unlubed bullets weighing 120 grains, .323" diameter with a heel. I'm assuming these are made from the RCBS mold that they sell.

3. Literature suggested several different case lengths - so I decided to trim the case, and press fit the bullet to determine an overall cartridge length that would chamber. This resulted in me determining that the overall cartridge length should be < 1.675"

4. To facilitate the overall cartridge length, I had to trim the cases to 1.150"

5. Using .310 cadet dies and a No.1 RCBS shell holder I resized, and lightly expanded the case mouth.

6. I used a Federal 205 small rifle primer

7. and used a powder load of 9 grains of IMR 4227

8. I hand lubed the bullets with Lee Alox

9. At the range, I used a chronograph to measure the ammunition velocity ten feet from the muzzle.

Ten rounds averaged 1089 fps with a standard deviation of 38.27

Does anyone have an idea of what velocity I can safely increase the load to produce? Cartridges of the World suggest the factory load was 1200 fps.

What kind of accuracy did you get? I have a cadet that was altered to 32-20.
I shortened the cases so that I could use a healed bullet. Lots of fun. I remember hering that some people used the actions for cartridges like the .218 bee so I would think that accuracy and leading would be of more concern.
john

I was not shooting groups that I measured as my main purpose was to chronograph the load.

However, I was shooting into a target set up at 50 yards. My observation of the holes was that it grouped very well.

I'll work up some more loads and the next time I'll shoot some groups and report back

You might try posting your question on the martini board or on the british militaria forum. There's a lot of very knowledgeable martini people there.
john

Amatikulu, If the firing pin isn't bushed, at about 26,000 CUP you will get primer flow back into the firing pin hole with WSR primers. If it has been bushed, you can safely go up to 40,000 CUP for the action. Case volume is about equal to 30 Carbine, if you need to reference pressure. HTH, Ric