British 303 brass

[jaguarxk120]

Is it possible to reform 30-06 brass into a rimless 303 British case. The new case would head space on the shoulder and be rimless.

Anyone done this? Or is it even possible?

[Hamish]

Have you tried it?

[Outpost75]

.303 British base diameter is .455" ahead of the rim. .30-'06 base is .473" diameter.
You could try turning OD of '06 case to reduce head diameter, reform and trim. Best to cast your chamer and turn OD to actual size to reduce body wall at head no more than necessary.

[EDG]

I have tried nearly the same thing forming .308 Win to 6.5 Jap.
The before and after diameters are the same only the length is different.
It would require a really heavy industrial hydraulic press and heavy duty dies or a great deal of patience.
I sized the heads of the .308 brass with the old style .44 Magnum steel dies that have an open top for the case to extend through.
I made up 25 cases and cracked 2 sizing dies in the process. Then I had to reduce the last 1/8" of the base to fit the smaller chamber.
The cases worked well but it was not worth the trouble.

Now I will just make the 6.5 Jap cases out of .303 by reforming and turning down the rim.
The best new .303 brass around is made by PPU. Or you can buy PPU ammo for less than $20 a box.
The Greek HXP .303 military brass is said to be ok but I would not know I have not worked with it yet.

Other cases I have used are the .444 Marlin which requires removing a few thousandths off of the head diameter and the .405 Win which has a rim that is a tiny bit too thick and the brass takes a lot of work and is very expensive but it should last a long time.

All in all unless you thrive on challenge and proving that you can eventually do anything you will not find it much fun for the amount of time and effort it takes.


Is it possible to reform 30-06 brass into a rimless 303 British case. The new case would head space on the shoulder and be rimless.

Anyone done this? Or is it even possible?

[Jedman]

I suppose it is possible as Grumpa makes 35 Rem. brass from 308 Win. A lot off work and you have to have the equipment. If you wanted to lathe turn them you could make the 303 Brit rimless, again a lot of work.

Jedman

[RogerDat]

Is it possible to reform 30-06 brass into a rimless 303 British case. The new case would head space on the shoulder and be rimless.

Anyone done this? Or is it even possible?

Not a direct answer but I can't help but thinking the whole thing with putting an "o" ring on the head in front of the rim to fire form the brass for over generous head clearance works because then case is going to headspace off of the shoulder from then on. Since that is something many have done it would seem that head spacing off of the shoulder is at least possible with regular 303 brass.

Why would you want to do this process to get rimless 303 brass - just curious.

[jaguarxk120]

I have lots of 06 brass --- not so much 303 brass.

I'll try turning off the extra .020 at the head of the case.

That way I can form the case's easier and won't have any headspace problems. The shoulder will be pushed back till the bolt close's.

[paul edward]

Is it possible to reform 30-06 brass into a rimless 303 British case. The new case would head space on the shoulder and be rimless. Anyone done this? Or is it even possible?

While this conversion is possible, it is a lot of work to make a case that is readily available at reasonable prices.

[paul edward]

I have lots of 06 brass --- not so much 303 brass. I'll try turning off the extra .020 at the head of the case.

Turning .020 from the head will result in very thin case walls. THIS IS DANGEROUS! DO NOT DO THIS!.

Better to spend your time seeing if you can trade some of your 30/06 brass for proper 303 British cases.

[runfiverun]

the 7.7 jap is a rimless 303 case.

[EDG]

It depends on which 7.7 Jap. There are 3. The rimmed case is the .303 aka 7.7X57R. This was used in aircraft machine guns in the Japanese Navy.
The semi rimmed version was a machine gun round. The rimless was both a rifle and machine gun round but it is not a rimless .303 British..

[bruce drake]

It depends on which 7.7 Jap. There are 3. The rimmed case is the .303 aka 7.7X57R. This was used in aircraft machine guns in the Japanese Navy.
The semi rimmed version was a machine gun round. The rimless was both a rifle and machine gun round but it is not a rimless .303 British..
The rimless 7.7x58 was loaded to .303 British pressure levels but you are right that it's not a rimless 303Brit due to its bigger diameter and longer length of the cartridge case. I use 303 Brit load data for my Type 99 Arisaka rifles all the time. A better rimless cartridge equivalent for 303 Brit is 7.62x53 Argentine Mauser. It's the same diameter bullet and almost the same length as the Brit cartridge.
But this post about converting the 06 cartridge to 303 Brit is a dream not worth sleeping on.

[Unclenick]

I do wonder if the OP has found an answer in the intervening seven years since the previous last post. Other than roll-forming, I don't see a practical method. You could make smooth wheels to replace the knurls on a scissors knurling tool, chuck the case in a lathe by clamping the neck over the appropriate 30 caliber steel rod, then apply the tool to reduce the diameters. But either this or roll forming will give you a lot of brass to trim off. In the end, you'd be investing a lot more in machinery than the cost of some new 303 brass, so you'd need to have other uses for the tools to justify it.