.310 Cadet Load

[Amatikulu]

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 IMR 4227 powder

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.

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[smle-man]

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 IMR 4227 powder

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.

Did you have to change the rim diameters on the .32-20 cases?

[Amatikulu]

No, the rim diameter was fine and no adjustment was needed.

[jmoore]

Any further load development to report? Pawn shop near my non-local hangout (gun store from which I post during daylight hours) had an unaltered cadet Martini that I just couldn't resist!

[Amatikulu]

jmoore,
For my rifle I finally settled on IMR 4227 powder. It gave me an average velocity of 1200 fps which from what I can determine is pretty close to the original. I'll be working later this month on loading another batch which I'll put on paper.

[tcattermole]

The original load would have had the case mouth crimped into the bullet's heel to increase the tension and hence improve consistency.
I found that I could dramatically improve the longer range (300 yards) grouping by doing the same.
Since a heeled bullet cannot be crimped in a conventional crimping die without damaging the bullet, I adapted a Lee 32/20 Factory Crimp die. The 310 is the correct diameter but wrong length, so I decided to insert the loaded 310 round nose down from above into the crimp die. To achieve consistent positioning, I constructed a length stop by jamming a plastic wall anchor into the middle of a spare shell-holder and then screwing down a woodscrew until the correct crimp position was achieved.
The crimp improves burning efficiency, so back off the load. I use Unique and a soft wad of dental wax under the bullet.

[JB White]

I also modified a Lee 32-20 FC die. To prevent dragging the bullet I beveled the crimp collet so the bullet passed through cleanly until the absolute final leg of the travel. Then I shortened it from below to locate the crimp.
It works fine on the long cases I made but misses on the original batch of shorties I bought. If I ever choose to go back to the short cases I'll just modify another die for those.

[Pete D.]

Just saw this thread. I have been using .32-20 cases bought from Graf and sons.
I have been loading and shooting them without sizing or using a seating die. I cast heeled bullets from a CBE mold and thumb press them into the cases. Any small rifle primer. I'm away from my load book and so cannot remember the exact propellant charge - either Unique 4.6 grains or 2400 ? grains.
They shoot well enough to give me this at 100 yards. The five shots in the ten ring are the last five consecutive shots. The others are sighters descending (actually they were ascending. The picture is upside down.). The hole at the bottom is from another rifle.
[IMG][/IMG]

[Jorge in Oz]

Hi there I'm new to the forum. I have an original BSA MArtini Cadet which I have yet to fire. I got 50 rounds of original Kynoch ammunition with it and an dditional 9 rounds that are not kynoch. My bore is in very good condition so I'm keen to test it out this weekend.

I've got a question, there was a dude that told me he fires 32 S&W Long from his cadet, has anyone fired these. He said the wadcutters are no good but the round nose rounds get good accuracy. There also a lot of people here down under that fire 32-20 rounds out of their cadets but some say there are headspace issues if you can fire 32-20 rounds, that I'm uncertain of.

Here's some pictures.

Cheers

Jorge

[TheDoubleD]

I've got a question, there was a dude that told me he fires 32 S&W Long from his cadet, has anyone fired these.

He said the wadcutters are no good but the round nose rounds get good accuracy. There also a lot of people here down under that fire 32-20 rounds out of their cadets but some say there are headspace issues if you can fire 32-20 rounds, that I'm uncertain of.

Here's some pictures.

Cheers

Jorge[/QUOTE]

Yes the 32 S&W case will fit in the chamber because the case is smaller and shorter. Kind of like shooting 38 SPL in 357 Magnum chamber.

Yes there is a headspace issue if you can chamber and shoot 32-20 in a .310 chamber. The headspace issue is with the thinner .310 rimmed case not the thicker rimmed .32-20 case..

To check head space insert a case and close breech, Then try to insert a .006" feeler gauge between breech face and case head. If the gauge goes in there is excessive headspace. If it doesn't go it's okay. This valid for rimmed cases in the martini chamber.