.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.

[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.
http://i492.photobucket.com/albums/rr287/PeteDoyle/Image050.jpg

[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

[Pete D.]

Jorge: I use 32-20 brass to load my cartridges for the little Cadet. The brass has been trimmed to 1.120" case length. Normal 32-20 cases are 1.31" long. That is a lot different - more than 1/5". Consider that the .357 magnum bullet was made 1/10" longer than the .38 Special so that it would not chamber in the weaker gun. This difference is double that. Wrong type of bullet also.
I cast the proper "heeled" bullet using a brass CBE mold that I purchased from The Ammo Dump, an outfit down your way. The address is NZ but the website notes that they are an AU based company.
http://www.theammodump.com/
It's simple enough to cast your own - not a lot of equipment required (a cast iron pot, an old camping stove, a dipper, some beeswax, the mold and a tube of liquid Alox lube.) You don't actually need dies at all to load the Cadet round. You do need a priming tool. And, of course, powder and primers.
Pete

[tcattermole]

The 310 Cadet's rim is very thin, so an unmodified 32-20 or 32 SWL shouldn't chamber. If the action will close on one, the rifle is probably out of headspace.
The 32 SWL bullets are undersize for the bore, but if the rifling is crisp there may (just) be enough engagement to stabilise the bullet. However, there will be a lot of gas blowing past that undersized bullet, so you should expect lots of leading from gas cutting.
TonyC

[TheDoubleD]

The 310 Cadet's rim is very thin, so an unmodified 32-20 or 32 SWL shouldn't chamber. If the action will close on one, the rifle is probably out of headspace.

TonyC

Actually only partially true. If it closes on a 32/20 cas it probably is out of head space for a standard .310 rim. But it might not be out of head space for .310 Cadet cartridge made a 32/20 case.

You will have to measure the gap to find out.

[Pete D.]

I do know that the little Martini that I put together chambers the brass from Grafs, headstamped 32-20. I haven't measured the rim thickness but I suspect that no one sat at a lathe and thinned every rim - not for the price that they ask.
I would like to acquire some proper .310 brass, though - just to have it. I wonder if brass is available from Kynoch. Just a few years ago, I was able to buy 577-450 brass from them; I shall have to check about the .310; I have an inquiry sent.
Pete

[TheDoubleD]

Buffalo Arms has both type of brass thinned rim 32-20 and Bertram .310.

[Pete D.]

Douglas: Pete from NY here. I'm assuming that the Bertram brass is good quality or you wouldn't refer me to it. IIRC, there were some issues with their 577-450 brass some years ago; consequently, I have stayed away from their offerings. I haven't heard back from Kynoch, though, so the Bertram looks attractive.
I suppose it has to be a step up from altered 32-20 cases.
Pete

[TheDoubleD]

I haven't seen any problems lately with Bertram Brass. For a short while Knynoch had Bertram make 577/450 for them.

The only brass from Bertrams I would shy away from is in some of the really obscure calibers that aren't seen much. I have some .375 Flanged Magnum that is pretty bad, it came in one of their old white pasted label box.

[zombie hunter]

The load I developed was 5.5gr of Accurate No.5 with the RCBS 120gr bullet.

I found with H4227 was getting alot of unburnt powder. So I modifed a Lee 32/20 factory crimp die

[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.

[Ray P]

TheDoubleD:

Thanks for the feeler guage info! Just checked my cadet franken-tini with new Bertram brass. Looks good :-) One step closer to getting it built & ready to shoot.

[graybeard]

Hi all,
I know this thread has been off line for a while now but I wish to let yuo know about my success with the BSA 310 cadet.
Being in northwest western australia I have problems getting hold of imported powders so I have built a load using the ADI 100 pistol powder.
Bertram 310 brass trimmed to 1.075" o/a length
LEE mould heeled projectile 125gn 0.316" diam or Hawkesbury River 125 gn projectiles
Any small rifle primer available
Ap 100 powder, 6gn
Chrony says I am getting 1150 - 1210 fps 10ft from the muzzel
I also tested some vintage Kynoch ammo and got 1180 - 1230 fps
Also tested Super brand ammo and got consistant 1200 fps

Hope you all get your 310's running as sweetly as mine.

[Simon P]

There was an article in Classic Arms Magazine in 1999 on loading the 310 Cadet Rifle, I used this as the basis for my reloading and shoot out to 300M quite accurately.

Modified 32/20 cases thin rimmed.
North Devon Fireams Services (NDFS) Dies
RCBS mould designed & sold by NDFS
4.5grns of unique
Lubed with Lees Liquid Alox

Jim at North Devon Firearms told me that he found Military 310 cadet rifles would often accept the 32/20 cartridge case without being thinned down, but this was not generally the norm for commercial rifles in 310 calibre, sadly NDFS are no more.

[Muzza]

G'day all

There is a wealth of knowledge about 310 cadets around. If any of you are still following this thread I have need of some expertise. I am having trouble with keyholing in my 310 cadet - a BSA. Was trying a new load 4.5gns Trail Boss, Federal small pistol primers 122gn .316 dia Hawkesbury River projies. Some rounds were fine - about 1 in 4 were tumbling. Any ideas please?

[jamie5070]

Have you slugged your bore? Maybe some of the bullets don't bump up enough to catch the rifling.
john

[tcattermole]

I find that my .310 is much happier when I crimp the load, as was the original. The tiny heel on the bullet gives poor neck tension without a crimp, resulting in variable velocities. The crimp also ensures a consistent initial pressure to obturate the bullet into the rifling (see previous response in this thread).

[Muzza]

Thanks for tips.
I've pushed one of the Hawksebury River projies from muzzle to breech, and found it pretty tight most of the way and definitely well-engraved rifling marks.

I have also adjusted the seating die to put a slight crimp on the case.

My previous load of 8.5 grains IMR4227 with small rifle primers was adequately accurate, but always some unburnt powder. When I finished the tin I swapped to TrailBoss and pistol primers on the advice of a club member. TrailBoss is very clean burning, so I want to persevere. Besides, I now have 1.5kg of the stuff. Any one else tried TrailBoss? I can't get much more in the case, but will try for 5 grains. What do you think small rifle primers would do?