Dilemma: Rechamber or Make labor intensive brass?

[gunluvver]

As I have previously posted, I have a Commission 88 carbine that has been sportered and rebarreled to 6mm Lee Navy, using a commercial Winchester 1895 Lee Navy barrel. One of the members here was generous enough to loan me a set of 6mm Lee dies as well as throwing in some .220 Swift brass. Forming the Swift brass into Lee brass was a no brainer, but the short case really bugs me. I'd rather have proper length brass, but sources of it are out of stock or extremely expensive. I've read that 30/06 brass can be reformed, with a little tweaking. I have an abundance of WW2 30/06 brass, so I tried my hand at it. I decided to do it in steps, so with some trial and error I came on the combo of running the brass through a 7x57 die to start, then a 6.5x55, then a 6mm Remington, shorten to 6mm Lee length, then run it through the 6mm Lee die. You can only run it through so far, then you have to reduce the base by metal removal. I'm chucking it up in the drill press and filing down the step left at the base until I can finally run it completely through the Lee die. I am not touching the rim, as the rifle is using the 8x57 bolt head and needs all the rim available. I ran the Swift brass through the gun, and it extracts fine. Hopefully after firing there is enough rim to facilitate extraction. After getting the brass to the point of being able to run through the Lee die, I still have a lot of polishing before it will chamber in the rifle.
After running the brass through the 6mm Remington die and shortening it, I noticed that base to shoulder length was nearly identical to the Lee brass I formed and fitted, with a slightly different shoulder angle. So the thought occurred to me: why no just rechamber to 6mm Remington? Using the 30/06 brass would give me the longer neck that I need and no mods would be needed to the base of the case. I wouldn't be damaging any collector value, as the rifle is already a mix of parts. I've ruined about 10 rounds of brass playing with it, and making the 6mm Remy would be SO much easier. So, any opinions? It goes without saying that the load data I use will not approach the 6mm Remington pressures.
This is after running the brass through the Lee die for the first time. You see the band at the bottom that needs removed before I can finish the reforming process.
296811

Here I have the steps I'm taking to form the brass: 30/06 parent, reform, to 7x57, reform to 6.5x55, shorten to Lee length, reform to 6mm Remington, reform to Lee, last is .220 Swift reformed to Lee.
296812

[dverna]

Can the action take the pressure of the 6mm?
If not, bad idea.

[Texas by God]

That's my concern, too. I'd be wary of the 88's strength being enough for the high pressure 6mm Remington.

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[MarkW]

Looks good so far! Have you tried it on new brass to see if you can swage that belt out instead of turning it off? I'm too lazy to look it up right now but if you know a machinist with lathe collets you can also use a collet chucked up to press that belt in. I'll be following this thread.

[gunluvver]

That's my concern, too. I'd be wary of the 88's strength being enough for the high pressure 6mm Remington.

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I won't be loading to 6mm Remington specs, I would use the Lee Navy specs.

[gunluvver]

Looks good so far! Have you tried it on new brass to see if you can swage that belt out instead of turning it off? I'm too lazy to look it up right now but if you know a machinist with lathe collets you can also use a collet chucked up to press that belt in. I'll be following this thread.

I have an abundance of surplus brass, that's why I'm going that route. It's a time consuming process going through all the steps. I didn't consider collets, but that's yet another step.

[Texas by God]

I can see where you're coming from. I once used a 22-250 reamer on a 6.5 Japanese chamber to make a "26-250" wildcat so I could use common brass. At the load level you'll be using, it should be ok. I wouldn't stamp "6mm Remington" on the barrel. My main concern would be if the old Winchester barrel will be accurate. There are some .236 USN shooters on CB that know all about loading it; hoping they chime in.

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[dverna]

H
I won't be loading to 6mm Remington specs, I would use the Lee Navy specs.

What happens down the road? Will you leave instructions to cut the receiver apart when you die?

[gunluvver]

H

What happens down the road? Will you leave instructions to cut the receiver apart when you die?

It'll go to my grandson along with all the info and brass.

[sharps4590]

Watch your case neck thickness. What is now the neck used to be the shoulder. It's rare I haven't had to thin case necks.
A lathe would make life much more simple.

[gunluvver]

I went ahead and formed up 50 cases to the shortened 6mm Remington point. I took one and filed the base diameter down before running it through the Lee die. I had a small belt left that I filed off, did a chamber fit, filed a little more, and it dropped right in. I ground down the tip of a drill bit to the point that it fits in the primer hole. I use it to ream the inside of the neck, then position it to support the case neck with the point supporting the primer pocket. I then chuck up the case in the drill and file the base down.

[paul edward]

The 6mm Navy Lee cartridge has a base dimension of .445. You could swage 30/06 cases down to that dimension and leave the rim in place. This would make it a 6mm Rimmed. You might have to clean up the front side of the rim in a lathe or drill press. This would be much safer than removing material. You would also need to ream the necks. I use a .448 swage to reduce the base diameter of 6.5 MS to make 7.35 Carcano brass.

It would, however, be much simpler to rechamber the barrel to 6mm Remington. Brass is readily available (or could be made from your stockpile of 30/06 cases). The 6mm Remington is not really new as Mauser did offer a 6x57 back in 1895.

[nvbirdman]

Yes, you will load down the 6mm Rem, but what about the next owner of that rifle?

[Driver man]

Your time is free. You have brass tools and desire. I would just carry on .

[gunluvver]

Your time is free. You have brass tools and desire. I would just carry on ..

I'm up to 18 rounds. 2 more and I'll load them up and take them out to shoot.

[MarkW]

FTI Midway has the Lee "Bulge Buster" kit on sale for $17, has one of the dies for 45ACP/45 Win mag which should pretty much work for 06 based cases:

https://www.midwayusa.com/product/102238662?pid=537390

Lastly, looks like the original parent bullet had an operating pressure of 43.5K so if you go with a 6mm Remington just engrave "Max Operating Pressure 43,511 psi" on the barrel below the caliber and you cover any future owners.

Post pics when finished!

[ascast]

i would re-barrel. I've had my fill of making cases for this or that. Hundreds spent on books, tooling etc. It was fun, I learned a lot. I still do it but limit it to squeezing down or blowing out. No more machine tools involved. just my experience have fun