shooting a 7mm Mauser Remington Rolling Block Model 1902

[vzerone]

Couldn't a person just expand 7x57 brass up to 30 caliber then size it back until it chambers. That sounds easier to me. I have 3 of them that were too nice to use as donors that I haven't had time to play with yet. I wasn't aware of the head space problem. So I'll need to plan accordingly when I start playing with them. Thank you for the heads up.
WW

Yes you could do that. It does work harden the brass though. Being the Rolling Block chambers are oversized the 30-06 brass is the better case to use because it is slightly thicker especially in the neck. That's because some of the new neck is from shoulder area of the 06 case.

[Reverend Al]

Yes you could do that. It does work harden the brass though. Being the Rolling Block chambers are oversized the 30-06 brass is the better case to use because it is slightly thicker especially in the neck. That's because some of the new neck is from shoulder area of the 06 case.

That's what I did with my 7x57 South American Rolling Block ... I used a tapered expanding mandrel to open the 7x57 brass up to about .30 calibre and then slowly adjusted the sizing die down until the block would just close. I've test fired it once so far with good results and I load it down appropriately to ensure that the pressures are sensible for this old rifle. The other thing that you will likely encounter (like I did) is that it also has an extremely long throat. I am loading 175 grain semi-spitzers and round nose bullets and have them seated out until they are barely held by the neck of the case. They are still well off the throat, but even though the bore is moderately worn in my rifle it shot amazingly good groups at 100 yards. (4 shots went into a nice round group of about 1 1/2" / 2" and one flyer that was about 2" left from the group ... but it was also the first round fired from the cold, clean barrel). Fit some brass to your chamber's shoulder length, load some 175 grain bullets at very moderate pressures, and enjoy that old gun! (I was loading 34.0 grains of IMR3031 and IMR4064, but of course you should work up to that if you want to try duplicating my loads. For me it shot equally well with both powders.)

[vzerone]

That's what I did with my 7x57 South American Rolling Block ... I used a tapered expanding mandrel to open the 7x57 brass up to about .30 calibre and then slowly adjusted the sizing die down until the block would just close. I've test fired it once so far with good results and I load it down appropriately to ensure that the pressures are sensible for this old rifle. The other thing that you will likely encounter (like I did) is that it also has an extremely long throat. I am loading 175 grain semi-spitzers and round nose bullets and have them seated out until they are barely held by the neck of the case. They are still well off the throat, but even though the bore is moderately worn in my rifle it shot amazingly good groups at 100 yards. (4 shots went into a nice round group of about 1 1/2" / 2" and one flyer that was about 2" left from the group ... but it was also the first round fired from the cold, clean barrel). Fit some brass to your chamber's shoulder length, load some 175 grain bullets at very moderate pressures, and enjoy that old gun! (I was loading 34.0 grains of IMR3031 and IMR4064, but of course you should work up to that if you want to try duplicating my loads. For me it shot equally well with both powders.)

The important is that you got the brass to fit better, got it shooting, and enjoyed shooting it. Can't ask for more then that. It's not the only rifle with an extra long throat that gives us reloading headaches. We have to remember that many of the old military rifles used exceptionally long heavy bullets so they were thus throated for them. Trouble is when we want to load lighter shorter bullets.

[Texas by God]

I've learned a lot this thread. And brian1 where are those pics?

[brian1]

Thanks for all the insights & info. The original "neck way too long" thing was just an initial experiment to see if I could push the shoulder back, having never tried anything like that before. That was just in lieu of either returning the gun or sending the barrel out to be rechambered. I looked in my books and picked the 30-06 as a caliber that I had buckets of brass for and had the same case head dimensions.

I figured it would be better to try to size down than to stretch the brass by sizing up.

I did as suggested earlier in this thread. I trimmed to about 0.015" longer than the "trim-to" length, then set my shoulder back. I was resizing old WWII 30-06 brass, which may have been thicker and tougher than newer brass. In the initial experiments, I was not annealing. I found that, due to brass springback, if I set the die all the way down for "normal" resizing, I ended up with the shoulder positioned at what looked to be about 1/16" forward of the 7mm brass. I set it so the block would just barely close and the hammer would completely fall.

In later experiments, I annealed first, and that made it go even easier. It also resulted in a bit less springback, which was OK because, probably due to wear between the hammer and block, I felt perhaps the block should be allowed to close a bit more, to address the possible "block face not perpendicular to the case head" problem if the block was closed only enough to allow the hammer to barely drop.

Once I got my anneal time set, using Tempilac (5 seconds in my torch), I annealed before sizing. I also started using some once-fired Remington brass, for more consistent results in resizing than the mixed old milsurp brass.

After I got all that set, then I made one with the shoulder right where I wanted it, but with a really long neck, and then started trimming the neck until the block would just close so the hammer would fall all the way without binding against the block. My 7x57mm Mauser brass is 2.225" OAL. Trim-to is 2.235". My initial cases were set to 2.250". By starting at about 2.290" and working down, I found that my zero-gap distance was with OAL of 2.266" with the milsurp brass, and 2.264 with Rem brass. I'm not sure why the difference in max OAL between milsurp brass and Remington.

I'm not sure what gap I should leave between the case mouth and the end of the chamber. Any opinions? I'm thinking something like 0.010". Maybe none at all for fireforming?

Because I had my little chop saw all configured for the cuts, I went ahead and cut up 60 of my Remington 30-06 brass, deburred them, and left them in the tumbler overnight. Next, I will anneal them, resize them, set final OAL, and then fire-form them for the final product.

Here is a picture of the initial experimental cases. Left to right are 7x57mm Mauser, 1953 mil brass, initially formed cold, later reformed after annealing, set to 2.250" OAL, 1942 mil case, same as 1953, then a 1953 set to 2.266" OAL.


For fireforming, I can either load up what should be a pretty light load, like about 18 grains of AA 5744 under a 145 grain bullet or 20 grains of IMR 4198 under a 175 grain bullet, or I can try the Cream Of Wheat method with some fast pistol powder and no bullet.. Any thoughts on pros or cons?

Thanks to all for all the helpful ideas, suggestions, and insight.

[brian1]

This picture is where I started:

Looong neck 30-06 after pushing back the shoulder, before any neck trimming, formed without annealing, next to 7x57mm Mauser case

[vzerone]

You done very well Brian. That distance or gap you asked about is just enough that if the brass grows from firing and resizing that it's not up against the end of the chamber. It's a safety thing so you don't ram the case mouth into the ledge and kind of crimping which won't let the bullet release easy and raise pressure much. You probably wouldn't experience that with the Rolling Block as it doesn't have much, if any, camming power, but a bolt action sure does!!

You're getting closer to shooting!!!!! Enjoy

[marlinman93]

Since your cases really don't need a lot of forming, I'd load them at whatever load you hope to use and simply shoot them. No need to do a light charge, or use filler to fire form them. I've built cases that had a lot more brass movement during fire forming and gotten great accuracy shooting targets while fire forming.

[Texas by God]

The gun, man. The gun. Quit teasing us with brass pics. Dang I'm a nag.

Sent from my SAMSUNG-SM-G930A using Tapatalk

[brian1]

The gun, man. The gun. Quit teasing us with brass pics. Dang I'm a nag.

Oh, the GUN It's night now, so hard to get any decent pictures, but I'll take some tomorrow

[brian1]

Here are the pictures of it.




Hmmm. What I uploaded was quite a bit larger. If you click on these, you get a larger version, but still not a large as what I uploaded.

[brian1]

[vzerone]

Not bad at all Brian, nice rifle! Have fun with and we better hear about how it shoots.

[TCLouis]

Anneal them before you fire them.

[marlinman93]

Wonder if those punch marks on the stock were "kill counts"???

[Reverend Al]

Wonder if those punch marks on the stock were "kill counts"???

I was just thinking that myself ...

[vzerone]

Maybe deer kills?

[marlinman93]

Maybe deer kills?

That's what I was thinking too.

[kootne]

There is some interesting information in the Oct. 1959 American Rifleman on this subject of headspace in military rolling block rifles. James M. Twiggs quotes James R. Lewis Jr. (then a patent attorney for Remington). In reference to the 7mm rifles, James Lewis says "almost without exception they are within the limits of the manufacturing gauges but this does not mean they are within the headspace tolerances of modern ammunition." He also notes the SAAMI standards for the 7x57 were not established until about 1920. In addition, he says the headspace compared to modern standards is "grossly excessive". However, in his experience, firing them with modern ammo didn't cause separations but all cases showed the bright ring characteristic of incipient head separations and could not recommend firing them "unless their use is limited to strictly fresh ammunition of characteristics consistent with the period of their original design and manufacture".
As an additional bit of information about the 7mm ammo, I have a couple Mauser clips of 7mm ammo dated 96 that I found in some of the effects of my great grandfather who was a veteran of the war with Spain, serving in the Puerto Rico campaign. The shoulder on this ammo is visually further forward than current ammo I compared it to. Makes me curious about whether this is an issue in 7mm military mausers. Also, rifles and ammo manufactured for military use probably don't have reloadability of fired cases very high on the priority list.

[Texas by God]

That's a great looking rifle.

Sent from my SAMSUNG-SM-G930A using Tapatalk