Making the rim larger????

So forming some cases for a 11mm Murata out of 348 Win.
The rim is to small.
Sometimes the extractor doesn't catch.
Any ideas on how to make the rim diameter larger????

How about building up the extractor a little?

Solder on a washer that fits the extractor.

It's a Type 13 Murata, and not mines.
Don't want to alter it.
Washer idea sound interesting.
But on the case, not the extractor.

If the headspace is good, then adding a washer will likely make the rim too thick to close the breech. That's why I suggested modifying the extractor. If you dont want to alter it, get another extractor to modify, then swap it in.

Use the Lebel case not the 348 case

https://en.wikipedia.org/wiki/8%C3%9750mmR_Lebel

Has a .630 rim diameter

https://www.grafs.com/catalog/product/productId/76747

the 348 has a .610 diameter

https://en.wikipedia.org/wiki/11_mm_caliber

I would be very nervous about heating up a case head enough to braze or solder on them.

Three44s

I agree^^^

I looked at different cases to make this out of.
The base of the Lebel is to small, M-542, L-536.
The 348 is 553 and fit well.
The 11 Murata has the same type of base as the 43 Mauser.
Kind of a double step base.
So I'm having to head space on the shoulder of the case.
Adding an O-ring around the base to fireform.
Seems to have worked.
I was thinking of making something to add a second rim above the 348 rim.
That would make the base, kind of look like the original, and would be bigger for the extractor to grab.
Need to take some measurements and see what I can find.
Interesting project.
There is a company that makes dummies for the 11mm Murata.
Might just have to get one.

Nonte's book on case conversion is where I think I saw a method that requires a lathe. Turn the rim down and leave an angle that flares out at the base. Turn a disk that just slips over the flare, then swage if down onto the flare to lock it in place and turn to final size. Three lathe operations for each case and two steel dies to make to do the swaging.

C-clips on the rim??. Frank

I make 11x59r Gras from 50-110 brass and have the same issue of correct body but small rim(head spacing from shoulder). I don’t have access to a lathe, but have thought about paying someone to turn a few washers to correct rim diameter with a recess around the inner diameter to fit the rim of the 50-110.

I tried sizing 50-90 brass down but failed once it made the donut at the head. Again… no lathe access.

Regarding the too small base of Lebel brass. I had a similar situation with a .44 rimfire cartridge I worked with a whie back. A solution I came up with was to wrap a piece of aluminum tape around the base to make it larger. I forget the tape thickness, maybe .004"? One wrap added .008", two wraps .016" etc. It was rather ugly, but worked well. Not an ideal solution, but it allowed me to shoot it.

Just throwing this out there. The parent case for the 50 Alaskan is the .348. Caliper measurements for a brand new Starline 50 Alaskan case is: Rim diameter .602. Head diameter just above the rim .545. Rim thickness .065, Length of case 2.100.

Use epoxy to add your rim washer, plenty strong and won't add heat. Modern epoxies were not around when some of the old cartridge conversion books were written.

I would consider a low temp solder like brownels sells. This and a hot plate would keep the cases as cool as possible. You could try relocktite instead of solder to hild the washers, but would make just 2 or 3 and test for longevity.

This would be more work but wouldnt require the heat either. Set the cases up and thread the rims to rim diameter x 36 or 48 threads per inch, then thread the washers to same. this will give around 4 threads engagement with locktite in them and a light interference fit they should last forever.

Either way a thicker rim and then cleaned up to original rim would be a good idea. If the rims are .070 make the washers .090 fit so you have .010 on each side to clean up the faces and make true.

While not a real hard job it will require some small fixtures and work, attention to detail and precise work

This is how some have accomplished the process.

http://dave-cushman.net/shot/44-06_rimmed_douglas.html

I saw that article a while back.
Thought of trying it, but never got around to it.

I don't think solder will get the brass not enough to make it all that soft.

Going to try the washer method.
Just need to find out how thick.
Want to see if I could find some brass flat stock make a hole to fit the case, and lathe the rim to size.
Then light solder on to hold.
Might work.

I think I might have found an easier way.
Fender washers.
They have different thicknesses.
Some really thin.
Probably have to bore out the hole to fit, but not to much of a problem.
The just machine the washer to size.
I'm going to see if they might make brass ones for boats.
Hope to find some so they don't rust like the metal ones would.
Another plan I was thinking of is copper brake washers.
But I'm wondering if the copper might be to soft.