7mm Rem. Rolling Block

[dualsport]

I have one I got back in the eighties. I've had some success with cast bullets in this gun, maybe 10-11" groups at 200 yds. I know that won't win any trophies but took a while to get there. My question is this, are they really a true 7X57 Mauser chamber? I've read about them being a little different cartridge. Anybody know anything about this? After fireforming my Remington 7x57 brass worked fine, just wondering if this story is known to anybody? If I recall it was not just a matter of the usual military sloppy chamber.

[NickSS]

They are a standard 7X57 Mauser but the rolling blocks tend to have large head space over time. I would keep my loads mild and neck size the brass. I had one about 30 years ago and it would give you head separations after only one or two reloads if you full length resized. A good gun smith can fix the head space but this required making larger pins for the hammer and breach block to pivot on.

[Buckshot]

............I have a model 1897 in "7mm Spanish" according to the barrel :-) The only issue I have with this rifle is the chamber neck size. After firing you can just about drop a 30 caliber bullet through the mouth of the case. Other then that it's fine. I normally only necksize anyway, so once they're fired they're pretty much set, and necksizing handles it.

http://www.fototime.com/51033A5247B82E1/standard.jpg

Here's 2 targets of 5 rounds each going a bit over an inch, fired at 50 yards using the RCBS 7mm-162 design. It weighs 172grs with lube and GC cast of 2ww-1 lino. Both powders shown are slow military surplus 50 BMG and 20mm cannon powder, and the velocity is shown for each. Without checking my records I know they were full caseloads, and IIRC it was like 60.0grs (they're both ball powders) or close to it. Pretty nifty results for issue open sights and a somewhat stubborn trigger :-)

..............Buckshot

[dualsport]

Thanks for the info guys. I found the reference I was thinking of regarding the different chambering. This is from an article in the CBA's TFS magazine 191-8. To just summarize, these RBs were chambered to 1893 Spanish Mauser specs, way before SAAMI came along. SAAMI specs are different than the old original German specs. This from "The Accurate Rifle" by John Campbell and "Book of Rifles" by W H B Smith. It's a long story but the bottom line is there's a significant difference. Those of us that have them just fireform and that's that, but it's an interesting story if you want to check it out. Oh, the CBA article author is John Rhodes of Virginia. I'm working with mine and an old Lyman mold for use in postal matches.