Rebating WSM Rims

[StevenCO]

I'm thinking of building something with a WSM case in a bolt action with a standard bolt face. I would like to simply rebate the rims of the WSM cases down to a standard diameter rather than going with any bolt modificatiaon.

It's a single shot bolt action, so magazine feed is not an issue.

Does anyone have any special advice they would like to offer before I go off the deep end....again?

Does anyone sell a tool bit that will cut the shape consistently to take out some of the potential for inconsistencies?

 

[Preacher]

Steven,
The extractor groove on the 300WSM cases I have mike out at .474 so I doubt your plan will work if you do the math, sorry if I messed up your plans..

 

[StevenCO]

It doesn't really.

I figured on needing to rebate the groove some as well. I think that is still well behind the case head as near as I can tell.

 

[Preacher]

I would tend to think it will be a little risky, and a lot of work for the $80.00 involved in recutting the bolt face and installing a Sako type extractor in it.....

 

[StevenCO]

I would tend to think it will be a little risky, and a lot of work for the $80.00 involved in re-cutting the bolt face and installing a Sako type extractor in it.....

I'm not sure what you mean "risky". Are you meaning safety? I know I'll have to pay attention to taking minimal material out of the groove. I was thinking of grinding a tool for that since I doubt that there is anything available.

I just don't want to modify the bolt since it is a custom action. I am more interested in just switching barrels when I feel like it. There is no going back to the standard once that is done... at least not without a lot of work installing a bushing and so forth. I could order another bolt I suppose, but that is probably substantially more than $80, though I guess I could check on that to be sure.

 

[NDNorm]

I have 7mm wsm brass and tonight i'll fly cut one in half to see how much meat is down around the base and i have 243 also and will cut one of those also to compare.
Norm

 

[StevenCO]

Wow - that would be awesome.

I await the results.

Thanks.

 

[NDNorm]

clean is wsm,black is .243

i could send these to you if you wish.
Norm

 

[StevenCO]

clean is wsm,black is .243
i could send these to you if you wish.
Norm

Norm,

I think I can get what I need from the photos. The parts are so small, getting measurements with calipers is probably not any more accurate than scaling it from your photos.

The comparison of one cartridge to the other stacked is great!
I think I see where the cartridge wall thickness at the case head is pretty close to the same as the 243 after rebating the rim with the same configuration,hard to explain). However, I think the stress in the case head will be higher due to the larger diameter of the WSM case. It tells me a lot in how to attempt to rebate the rim in order to maximize the remaining material.

This will be interesting.

Thanks for doing that. I really appreciate it.

I will let you all know how it all goes.

 

[JayIdaho]

I did this a few years ago. The parent case was a .348 Winchester. It is a rimmed cartridge but we eliminated the rim and recut the groove. The wildcat cartridge was a .338, very close to a 338-300 WSM which had not yet been designed.
I ground a tool to do it all at one time. The brass was tapped into a die that had been dialed in in the lathe. We just touched the front of the rim and dialed in the amount needed to give us a case/rim that fit a Remington magnum bolt face.
It worked fine.

 

[StevenCO]

Do you have any photos of your process you could post?

 

[JayIdaho]

No, it was just a simple lathe operation. I do have a modified reloading press ram that I put in the tailstock, position it and drop a shellholder over the case rim and into the ram slot at the same time. This facilitates removing the modified case from the die after rim modification.

 

[TRECustom]

StevenCO; The biggest problem I could see was holding the cases to cut the rim and groove down. JayIdaho's method is a classic example of the old adage, "The solution to any problem can be fantastically complex or ridiculously simple". Not only is it simple, it is very stable.

Grinding a tool and setting up stops to make the heads uniform will be easy. Holding the case had me stumped.

Sounds like you've got a plan. Tom

 

[NDNorm]

Steven ever do anything with this?
Norm