I Picked Up These 277 Sig Fury Cases At The Range

[jackieschmidt]

I wanted to see how it was constructed.

I am not up on all of the latest staging techniques, so I do not know exactly how they put this together with that locking feature.

I also chucked one up and using a sharp tool, took a cut on the steel rim. It is definetally some type of free machining stainless, maybe regular 416.

Just curious.

 

[hoz53]

I wanted to see how it was constructed.

I am not up on all of the latest staging techniques, so I do not know exactly how they put this together with that locking feature.

I also chucked one up and using a sharp tool, took a cut on the steel rim. It is definetally some type of free machining stainless, maybe regular 416.

Just curious.View attachment 1626754

that is interesting— so do you think the brass is heated so it fuses somehow to the steel or is it just the ridge that holds it together?

 

[rijndael]

This goes in to how it's made, but I don't see a wedge in your picture.

 

[Walt Krafft]

The head is formed with the recess. It is 416 or very similar. A brass tube, looks like a cartridge, is placed in the head. It is then hit like seating a core in a bullet. This upsets the brass into the recess. That is a very old video. No locking washer is used. When fired, if it wasnt fully expanded into the recess, 75-80k psi will finish the job.

 

[rijndael]

When fired, if it wasnt fully expanded into the recess, 75-80k psi will finish the job.

I hadn't considered that. Thx.

 

[jackieschmidt]

All I did was grind the side away. It looks like 2 piece construction.

 

[Walt Krafft]

Yes it is just 2 pieces.

 

[jackieschmidt]

Yes it is just 2 pieces.

Aside from not being able to size the steel head down in a conventional die, is there any reason this could not be reloaded?

 

[3Ackleys]

Aside from not being able to size the steel head down in a conventional die, is there any reason this could not be reloaded?

I believe they are reloadable. There are some guys wildcatting them- necking them down to 6mm etc.
I don't thing the steel base would grow much, so it prob. won't need resizing.

 

[AlNyhus]

Aside from not being able to size the steel head down in a conventional die, is there any reason this could not be reloaded?

Jackie, the late Al Matson was doing quite a bit of work with that case when he passed. He had made a fixed neck full length die and told me he hadn't had any issues.

 

[Walt Krafft]

The steel head expands if you run it at the design pressure, but doesnt spring back like brass. If you do size it down, when will the steel fail like a head seperation? How many reloads? I sure dont want a head seperation at 80k.
Another problem is the head expansion creates a ring in a non-chrome plated chamber making extraction very difficult.

 

[WSnyder]

the late Al Matson was doing quite a bit of work with that case when he passed

As in alinwa? If so wasn’t aware he passed away.

 

[jelenko]

Another problem is the head expansion creates a ring in a non-chrome plated chamber making extraction very difficult

Whoa!

 

[Knotwild]

I guess my fears are unfounded because people are already reloading them. I used to reload steel 45 acp cases just as an experiment - they eventually cracked.

My original fear would be failure at the joint where the case head is attached due to work hardening.

 

[hoz53]

The steel head expands if you run it at the design pressure, but doesnt spring back like brass. If you do size it down, when will the steel fail like a head seperation? How many reloads? I sure dont want a head seperation at 80k.
Another problem is the head expansion creates a ring in a non-chrome plated chamber making extraction very difficult.

thanks for the info Walt. do you know how much steel expands?

 

[46and2]

I wanted to see how it was constructed.

I am not up on all of the latest staging techniques, so I do not know exactly how they put this together with that locking feature.

I also chucked one up and using a sharp tool, took a cut on the steel rim. It is definetally some type of free machining stainless, maybe regular 416.

Just curious.View attachment 1626754

Hey Jackie, is this an inclusion or just an optical effect?

 

[jackieschmidt]

I scratched around on it with a needle. It’s just discolored brass.

 

[Walt Krafft]

I have said it in other threads, but would like to repeat it. This case does NOT show pressure like a brass case. Flat primers, you betcha. Head expansion, yes. Hard bolt lift, maybe. You must have some sort of pressure testing equipment. Normal cup and core bullets do not like that much kick in the butt. The same performance can be had with a 270wsm at normal pressures.

 

[Jud96]

I think this is the way to go for high pressure cases, assuming they’re consistent in weight and dimensionally consistent. If it’s run under max rated pressures, the steel shouldn’t expand so there wouldn’t be a need to size the base, but you can still size the brass body, neck, and bump the shoulder. The benefit would be running 75k psi comfortably without wrecking primer pockets. Neat stuff

 

[AlNyhus]

As in alinwa? If so wasn’t aware he passed away.

Yes. He passed in Sept of 2023.