Quirky load for 32 Win Spl

[LeftHandGuy]

For reasons that I won't go into here (probably post a whole different thread about the rifle once I get a few more things sorted), I need to develop a load for 32 Winchester Special using a 139 grain jacketed soft point bullet.

Looking at load data for 32 Win Spl and 30-30 WCF, I have started at 29.5 grains of Hodgdon Leverevolution (largely because I had it and it seems to offer good velocity and low pressure)

However, I have got two noticably bulged primers


So obviously I have issues with this load!

The way I see it, I have three options:

1) Dial the load back substantially

2) try a slower powder

3) try a faster powder

What would any of you try (and why)? I am not looking for load data, rather what principles I can use to bring the pressure down.

I initially thought that a slower powder might help, but consulting a burn rate chart I see that Leverevolution is already slower than most of the typical lever action cartridges.

The rifle shoots factory Winchester 170 grain without bulging the primers, and the bullet is a .323 PPU bullet sized to .321, which matches the bullet size of a bullet pulled from a factory round. The rifling groove diameter seems to be .3205 at its deepest. And the brass I am using is necked up 30-30 brass.


This is my load next to a factory load for a visual comparison.

 

[Smellydog]

I'll have to check but thought 32 win sp has a thicker rim.
The issue you have with the primer is indicative of excessive head space. Which you will have if 30-30 rims are thinner.
I wouldn't size the bullet either, provided it chambers.

 

[Smellydog]

Scratch that...looks like the rims are the same thickness.
It could be excessive head space though or it could just be a lack of pressure. How?
The initial peak pressure has the case grip the chamber like normal but there is not enough residual pressure left to thrust the brass back to the bolt and swage over the primer.

Try a slightly lubricated case.

 

[alberta boy]

Is this for your rechambered Martini ?

AB

 

[LeftHandGuy]

Is this for your rechambered Martini ?

AB

I can't hide anything from you!

 

[Rookandrabbit]

I love the old 310 cadet martinis very accurate however when yours was rechambered to .32 special was the firing pin reduced in size and the front of the block bushed to accommodate the smaller pin? Just a thought.

 

[Muir]

Too light a load. ~Muir

 

[LeftHandGuy]

Scratch that...looks like the rims are the same thickness.
It could be excessive head space though or it could just be a lack of pressure. How?
The initial peak pressure has the case grip the chamber like normal but there is not enough residual pressure left to thrust the brass back to the bolt and swage over the primer.

Try a slightly lubricated case.

Thanks @Smellydog I can certainly try a gentle lube of the case.

I am interested that you suggest not sizing the bullet though. My sized bullets measure the same as the factory bullets I pulled, and the factory ammo doesn't get the bulged primers...

If it is that my pressure is too low, wouldn't it be safer to build up the powder charge, or try a faster powder?

 

[LeftHandGuy]

Too light a load. ~Muir

Thanks! I will try a little "working up"...

 

[Smellydog]

What is the rifle?
New cut chamber? Highly polished?
The full sized bullet if it will chamber will boost initial pressure mate.

Sounds interesting

 

[LeftHandGuy]

I love the old 310 cadet martinis very accurate however when yours was rechambered to .32 special was the firing pin reduced in size and the front of the block bushed to accommodate the smaller pin? Just a thought.

I'm a bit too ignorant about real gunsmithing to properly understand your question here. I have heard of these conversions needing or benefiting from having the feed ramp relieved to allow the (much) bigger 32 Win Spl cartridge to chamber and extract, but surely the breach face and striker should have remained unchanged? Obviously the chamber is reamed out and the extractor relieved, but I assume they would have removed the barrel to do the chamber?

Either way, thanks for the interest, and yes I have an emotional association with the Martini action that goes way beyond any practical or sensible explanation!

 

[LeftHandGuy]

What is the rifle?
New cut chamber? Highly polished?
The full sized bullet if it will chamber will boost initial pressure mate.

Sounds interesting

Australian Contract BSA Martini - it has the 'Roo above the chamber and everything!


Apparently the 32 Win Spl Conversion was a common one because the bore/groove diameter for the 310 Cadet was already close enough to the Winchester that the whole job could be completed reaming the chamber and relieving the extractor. Obviously not too much thought was given to what it would be like to actually shoot the thing with factory loads, and weather or not the 1:20 twist rate would be any good for the factory bullets.

Unsurprisingly, factory loads were not especially "conducive to accuracy"!


Which is the reason I am working on a load for a lighter bullet (that, and the fact that 32 Win Spl ammunition is extremely rare and what you can find is very expensive, like $59.99 for a Yellow and Green box of Remington)

 

[Stalker62]

I have one of these lovely old .310 Cadets.

It is still in its .310 chambering, and there may be some on here who will recall my horror stories of trying to cut 32-20 brass down to .310 brass.

Days of anguish, money thrown down the drain and precious life wasted on that little nightmare.

I have now (thanks to a SD member) sourced some 'proper' .310 brass - not cheap but at least it fits the rifle.













Good luck with yours.

 

[Rookandrabbit]

I'm a bit too ignorant about real gunsmithing to properly understand your question here. I have heard of these conversions needing or benefiting from having the feed ramp relieved to allow the (much) bigger 32 Win Spl cartridge to chamber and extract, but surely the breach face and striker should have remained unchanged? Obviously the chamber is reamed out and the extractor relieved, but I assume they would have removed the barrel to do the chamber?

Hello LeftHandGuy afaik the chambering to .32 Winchester Special was done when the bulk of the 310 cadets were sold off into America in the 1950s sorry can’t recall who imported them but recall seeing reproduction adverts listing them for about $15 dollars! They used a pull through reamer in two parts to do it never seen one but read about it.

work was done to reduce the firing pin size for high pressure cartridges and the breech face was cut back and a hardened steel shim/ plug drifted into a dovetailed slot. This is detailed in frank de Hass book. If it has not been done on conversion the firing pin is quite large and pressure can set the primer back Into the firing pin hole causing the action to freeze with an empty cartridge in the breech. De Hass details it in his single shot rifles book.
I bet it’s a beast to shoot in .32 Winchester Special!
I know this as a member of my club had one in 357 that he stoked up and encountered this problem.

 

[Rookandrabbit]

I have one of these lovely old .310 Cadets.

Beautiful rifle did you know you can use cut down 7.62 Nagant revolver cases cut they need to be cut down in length but the rims are correct size and much cheaper than Real 310 Cadet Cases!!
I saw this on the cast Boolit site…….well worth a read if held on section 1 in UK.

 

[LeftHandGuy]

Hello LeftHandGuy afaik the chambering to .32 Winchester Special was done when the bulk of the 310 cadets were sold off into America in the 1950s sorry can’t recall who imported them but recall seeing reproduction adverts listing them for about $15 dollars! They used a pull through reamer in two parts to do it never seen one but read about it.

work was done to reduce the firing pin size for high pressure cartridges and the breech face was cut back and a hardened steel shim/ plug drifted into a dovetailed slot. This is detailed in frank de Hass book. If it has not been done on conversion the firing pin is quite large and pressure can set the primer back Into the firing pin hole causing the action to freeze with an empty cartridge in the breech. De Hass details it in his single shot rifles book.
I bet it’s a beast to shoot in .32 Winchester Special!
I know this as a member of my club had one in 357 that he stoked up and encountered this problem.

Thanks for the added explanation - certainly makes sense - I will look next time I have the action out.

 

[Stalker62]

...did you know you can use cut down 7.62 Nagant revolver cases ... they need to be cut down in length but the rims are correct size...

Monster!

Did you not read wot I wrote about me, and "cutting/trimming' down brass?

I am so done with that bollocks.

 

[Smellydog]

Australian Contract BSA Martini - it has the 'Roo above the chamber and everything!
View attachment 289434

Apparently the 32 Win Spl Conversion was a common one because the bore/groove diameter for the 310 Cadet was already close enough to the Winchester that the whole job could be completed reaming the chamber and relieving the extractor. Obviously not too much thought was given to what it would be like to actually shoot the thing with factory loads, and weather or not the 1:20 twist rate would be any good for the factory bullets.

Unsurprisingly, factory loads were not especially "conducive to accuracy"!
View attachment 289436

Which is the reason I am working on a load for a lighter bullet (that, and the fact that 32 Win Spl ammunition is extremely rare and what you can find is very expensive, like $59.99 for a Yellow and Green box of Remington)

Hmmm, a lot going on then!
How about going to a cast bullet?
Pending breech face modifications check out maybe fire forming the brass may help.

 

[Smellydog]

Just out of interest but I don't know what your purpose for the rifle is but I'm getting good results with just 8.5gns of Alliant Herco.
Probably between 1100-1500 FPS. Sealed cases with 150 jacketed.
If you go that route just don't push it!

 

[enfieldspares]

Too light a load. ~Muir

I think so. That's a primer backed out and then either not enough pressure in the case to set the case back and re seat the primer or a load with excessive headspace.