Remington Rolling block 7 x 57 twist rate?

I bought, sight unseen (yah, I know) a 7 x 57 Roller, likely a 1901 or 1902. Trying to think ahead a little with component and mold shortages being what they are...can anyone hazard an opinion as to the twist rate?

Cartridges of the World lists it as a 1:9" twist, but not sure if the Rolling Block used the same? Probably best to wait a little and check yours for certain before ordering much.
That said, I can't see how you could go wrong with a cast bullet mold of around 150-160 grs., even if it's a little slower twist.

I have some 168 gr RCBS I cast up and am fixing to reload in my 1902 with a mint bore in 7x57, will let you know how they do.

Koger, Please do check back. I've got a bunch of old,old Barnes 195 gr jacketed and an unnumbered .287 mold that will throw a roundnose almost 1.5 inches long. Running the numbers, I'm no math whizz, but it looks like I need about a 8 1/2" twist.

I have seen in print somewhere that at least some of the mil surp 7x57 were 1 in 8.5 ...and that seems to check with the uraquay carbine I have.

Dredging up an old discussion.

I have a m1902 Uruguay RB carbine on the way. I understand the chamber difference from modern 7x57, so no need to rehash that. But I'd be interested in hearing loading experiences and tips.
Thanks - Steve

I’ve had good luck with 168gr RCBS with GC., 10.5 gr of Unique, WLR primers and what ever brass you can find.

you know the chambers in those are oversized? That is larger in the base than any other Mauser. Something about mis sread prints or some such. Anyway, mine will shoot 3 times on full sizing before head seperation. I don't remember the loads I was using. Just mentioning the neck size only. My seperating loads were full power, probably j-wads.

Yes, I'm aware that some, but not all have oversize chambers. Thanks. I'll check this one when it arrives.

I have many older rolling block rifles, but never a 7mm, and have been told that the cases last longer if they are indexed to the same position in the chamber for each shot. Makes sense if the pins have any excess tolerances.

I neck size mine with a redding bushing type sizer. shooting the lee 135 grain I lapped out to .288" shoots ok for a rough bore, I index the cases as mentioned. 18 grains 2400. Not sure if indexing the cases helps, but easy to do with a single shot. Using PPU brass, loaded 3 or 4 times with no issues so far.

Thanks guys. I've read that in some cases, the block face is not exactly square to the bore. The resulting rim face deformation is why it is good to index the case the same each time.

I have successfully shot both 150, and 168 gr cast in my 7x57 RRB using 18 gr/2400. By successfully I mean shooting from the kneeling position with the rifle's open sights and bad eyes at a target 50 yds away and with a target bulls-eye of 4" diameter. I can generally place all shots within that diameter. I have also tried shooting 135gr Cast but those slugs tend to open up my group.
The throat on the RRB is huge, lots of room, so pay attention to the seating depth when you reload. I also only neck size the brass after the first fire forming.
in Freedom
atr