With the pandemic it is darn hard to find cartridge cases and/or ammo. In a normal time I would go to your friendly guns shows and look for what I need.
I am going to chamber my project barrel very soon which means I have to cut the rim the correct depth plus proper headspace. The caliber is 7x57 Rimmed. When I chamber I for a rimmed cartridge I like to have a few different case makers brass so I can compare the rim thickness variation.

So the favor I ask is if you have any 7x57 Rimmed ammo and a micrometer could you measure a couple or each variation you have and give that data to me? Please tell me the manufacture or headstamp and then the thickness of the rims. either inches or metric are find.

Thanks in advance

Lrf,

I have some 8x57R, someone else on the site may be able to confirm this but, I believe you can run the 8x57r brass into a 7x57 sizing die and end up with what you need. If you are close enough to pick it up I can spare half a dozen rounds of brass if you like. Would make headspacing a lot easier with actual brass rather than just dimensions...

I looked but unfortunately do not have a set of 7x57mm dies or I would lend you those.

WBLDon

I have a box of fired Sellier & Bellot 7x57R brass
There are 18 fired cases in the original box

If you would like, I will send them to you.

Further, I can full length size any of the cases you wish before shipment.

You can most usually use a 303 Brit case and size it in a 7mm Mauser full length die
and trim to proper length.

Mike

p.s.

Headstamp
S&B 7x57R

Rim Thickness
.060

Rim Diameter
.525

Complete chamber and cartridge dimensions are here:'
https://bobp.cip-bobp.org/uploads/tdcc/tab-ii/7-x-57-r-en.pdf

'Rim thickness is around 1.5 mm for both GECO and SHM 7x57R cases

SHM:
https://huelsenmanufaktur.de/de/home_2020/

Thanks for the responses from all.


Hi Mike, the only 7x57 brass I have is a partial box of Sellier & Bellot. I measured my cases and they range from .057" to .060" and vary a little even on the same case. Your measurement confirms my findings for S&B brass. I appreciate your offer to send me yours, however not necessary at this time.
I am hoping to find someone who had some other manufacturers bras such as Norma and there are of course others. If you have some and can measure them please do so and send me the data.

I can just chamber for the print dimension plus SAAMI headspace which would be .070", however their normal .007" headspace seems a bit much and that is why I wanted to see what actual variations of the cases run.

I have RWS cases that measure .060 rim thickness.

Noted! Thanks Bill

At this moment I am thinking the counter bore for the rim will be .064" deep or basically the max spec for the 7x57R case rim. Of course that is the distance from the bolt face. There is .007" clearance between breech end of barrel and bolt face so. .064" - .007" = .057" actual CB depth as depth mic'd from barrel breech face.

I'll wait a day now hoping to get one more rim thickness from a Norma case

LRF,
The 7x57 case( including 7x57R) is based on the M93 case, which is .473" head diameter, instead of the M88 case( 8x57/8x57IR/IRS) which is .468"(both dims. max). Most European cases follow this, but American cases are usually made 06 size( incl. 6.5x55). You might keep this in mind if you intend to use European cases.
Mike

I am and will, thanks. Its one of the reasons it is nice to have a few different cases when chambering any rifle. However the COVID is making that a challenge.

There is a small local gunshow this weekend and of course the big Sioux Falls gunshow next weekend. Since I am immune to the sickness I am planning on attending both if possible. 7x57R is n-#1 on the look for list.

Further on the subject Mike noted. "Custom Cartridges" by Ken H, shows the head diameter of both the 7x57 Rimmed and Rimless at .474" diameter. Factory Remington 7x57 (rimless) actually measuring .466" diameter. As you know there are many many versions of the 8x57, and most show .470" to be the diameter, with one version being ~.468" diameter. However I don't think this info about the 8x57 is really not pertinent to the subject concerning the 7x57. Kind of apples and oranges, uness your forming brass and if the chamber is .473" I can't see any concerns at all.

(Opinion: I believe factories intentionally form their brass to the low specs because it better insures their ammo will fit in your rifle which is the mission of course)

RWS .059"
Norma .061"

Thank you

I quickly learned to set my FL sizing dies to headspace on the shoulder, instead of the rim( i.e. to just "kiss" the shoulder), to guard against head separations. This means that as long as the cartridge will chamber, headspace isn't much of a concern. The chambers for rimmed/belted cartridges have often been long in the body, creating excess stretching from FL sizing/firing, which leads to case loss. Out of habit, I size rimless cases the same way. This is only a suggestion.
Mike

I chambered the rifle using 7x57 Mauser reamers and headspace gauges and cut the rim in a separate operation to clear the max rim thickness. My reloading dies are also std 7x57 Mauser dies.

LRF,
I wasn't implying you did anything wrong, everything is manufactured with tolerances( there is about .006" between 06 length "go" and "no go" gauges), and following some die manufacturers instructions often results in shorter than the chamber cartridge cases.
Mike

I didn't take it that way at all. I actual would tell people Mike has a valid idea and for all intent and purposes we are saying the same thing.

LRF,
I noted, more than once, where you agreed with something I recommended. Thanks.
Mike