Making 7x57mmR from .303 British

[corbinace]

I did not see any 7mm rimmed brass available, so I got to looking at what was close.

303 is very close. The rim is a bit larger diameter by .009". That is ok for me as I will be using a lathe to cut the rim rebate in barrel breach.

The base is .014" too small but a piece of cellophane tape around it would center for the forming shot.

The case is .022 too short but will stretch a bit when necked down and that little short will be just fine with me.

What do you think?

[challenger_i]

PM sent.

BTW: they do not allow attachments in PM, so this is for you:

[swamp]

Last time I checked Grafs had it in stock. I shoot it in an Encore. swamp

[j4570]

Grafs has it:

https://www.grafs.com/retail/catalog...roductId/74148

In addition to PPU brass, they have 7x57R ammo in stock:

https://www.grafs.com/retail/catalog...roductId/26786

It’s probably really hard to load ammo for that price. The brass cost almost as much as ammo!

I’ve had good results with the S&B 8x57JR ammo. So good I don’t load for it.

[Jedman]

I have a wildcat round that is 7 mm and formed on 303 British or 30-40 rimmed brass. It’s a shortened 7 x 64 die cut off to where the base ID is about .454 . I would include a picture but my iPad has to many pics stored and it will not let me add a new pic and post it. I can’t find a way to delete old pics in the Castboolits file ?
Jedman

[JRD]

Unless you really want to make it yourself, European PPU/PRVI or S&B is readily available. Consider that PPU virgin brass costs $49.99/50 ($1 each) at Grafs while S&B LOADED AMMO costs $21.19/20 ($1.06 each).
Heck, just buy S&B loaded ammo, enjoy shooting it, then have a supply of once fired brass to start reloading.

[steveu]

I did not see any 7mm rimmed brass available, so I got to looking at what was close.

303 is very close. The rim is a bit larger diameter by .009". That is ok for me as I will be using a lathe to cut the rim rebate in barrel breach.

The base is .014" too small but a piece of cellophane tape around it would center for the forming shot.

The case is .022 too short but will stretch a bit when necked down and that little short will be just fine with me.

What do you think?

Why???

[kootne]

It sounds like you can get the loaded ammo and brass. The correct headstamp is always worth a bunch to me. But so is a "Plan B". If the right stuff is there, grab a bunch. But if it dries up, (which has happened a lot to various reloading components over my lifetime), take a look at using .444 Marlin brass for your Plan B. It is pretty much a "Basic" rimmed x57 case. I'm just now measuring one; Rim= .508 dia, .057 thick, head = .468 dia, case mouth = .446, OAL = 2.212

[j4570]

444 Marlin was once the choice for forming 7x57R and 8x57R. However, 444 Marlin Brass is more expensive than buying loaded ammo for 7x57R or 8x57R right now.