Rolling Block #5 M1902 7x57

[gnoahhh]

Any insights/pet loads for feeding one of these things? I picked up a dandy one with a nice bore (pretty unusual, that) and am gearing up to shoot it. I'm totally aware of the need for lower pressure ammo, quirky chamber dimensions and know how to allow for that, as well as propensity for out of round chambers (orienting cases into chamber same way each time). What I'm looking for are observations and perhaps pet loads (cast and jacketed) that may save my re-inventing the wheel. Thanks!

[ascast]

7mm - do not full size your fired cases. you will get 2 maybe 3 shots before catastrophic failure

[gnoahhh]

Yep, plan to neck size only after creating correctly headspaced brass.

[Mk42gunner]

I never had one, and may never; but I do wonder sometimes what the groove diameter of the barrel is on those rifles. We have all read of the differing chamber specs for the 7x57 over the years (especially in a Remington Rolling Block) and something in the back of my brain is whispering .287" bore diameter.

Just thought I'd ask,

Robert

[gnoahhh]

This one mic's at .285" groove diameter. I'll shoot jacketed a .284 bullets but am planning on .286" cast which equates to throat diameter. Already made a .285 neck expander plug for my RCBS neck expander die. Now all I need is a couple of molds.

[Adam Helmer]

Many Thanks for the trip down Memory Lane. In 1961, I bought a 7MM Rolling Block for $7.67 from Ye Olde Hunter and a case of 7mm Winchester ammo for $10.00. I still have the rifle and do shoot cast loads out of her. Do not over size any cases, not just the RB cases in reloading.

My old 7MM reminds me of the Old days when I was 16 years old and just beginning to collect wonderful military surplus arms back then before the 1968 BATFE Gestapo!

All laws were always in place about criminal use of guns before GCA 1968, but now BATFE requires we Continually KEEP SCREENING Honest Citizens while NO criminal ever enters their corrupt INFO into the System. Go figure...

I am a retired federal lawman and must say during my 26 years in ANTI-GUN Massachusetts, THEIR Gun Control Laws affecting ONLY Honest Citizens NEVER solved any case I worked.

Adam

[atr]

I've had one #5 for years...I bought it for $7.00 way back in the mid 60's before the gun control act. I was in High School then. I generally size the boolits 0.001 over and accuracy is pretty good given the open sights and my poor eyes, i.e. I can usually consistently hit a paper plate at 75 yds. Yes neck size is better than full length if you want to get the most reloads from your brass. The longer and heavier bullets, both cast and J's work best. I think you will find that the throat is pretty big. Make sure the breech block closes up square to the chamber. I have shot J's with IMR 4350 at 85% maximum and cast at about 1800 fps. I know that my older Sierra reloading manual (copyright 1971) specifically states that their loads for J's were developed with old military rifles in mind. You will have to work on getting the bore clean and you will never get the pits out, but the rifling is generally strong. I have found that you can make 7x57 brass out of G.I. 30-06 cases, as brass is a bit hard to come by. Although the GI brass has slightly different head dimensions it usually works in the 7x57 chamber.
Make sure the crown of the barrel is not bunged.

[Jedman]

I owned one for about 5 years and always resized 30-06 brass to fit the chamber. Back then I had some Accurate # 8700 powder that was very slow burning and could use a full case of it with 175 gr. boolits and was getting about 3 MOA at 100 yards.
Jedman

[Cessnapilot89]

Picked up one at a garage sale yesterday. I was surprised how accurate the rifle is.

[atr]

I found mine accurate also, even with my bad eyes and the iron sights. I have often thought about putting a scout scope on the rifle, I may do it yet.