OK, so I have a nice pre-64 M70 standard action including the trigger. First three serial numbers are 225, which I believe places it from 1951. I'm toying with a new build project and having a 7x57 barrel installed.

Will this be the right fit? I know some makers squeeze the 7x57 into their version of a short action. So with the Winchester pre-64s the 7x57 should be fine as I understand it. My concern would be that the feed rails work for this cartridge the same way it would for the 30/06 or other "standard" cartridges. I don't want a rough working action. If I'm going to spend the money over the coming years that I think I'm going to spend on this endeavor, I want a nice smooth setup....thoughts?

7x57 has it's place, but if it were me and a 7mm was on the menu, I'd belly up to a 280 Rem or 280 Ackley and never look back.

I agree. Lips, box, follower all will play nicely with a straight .280.

Stick with your plan, 7x57 only .010" less body taper than '06...it will feed flawlessly. I have built two .257 Roberts on pre 64. Customer very happy.

Actually I think the action is from 1952 with that serial number. Anyway, I'm looking to keep this somewhat original for the times...and the 7x57 was around then. The 280s didn't come along commercially until 1957...picky maybe on my part but so be it. So for extra panache, I think I'll have the barrel maker stamp it with "275 Rigby".

^^ this ^^ i own a pre-64 257 Roberts and have also built 2 - 257 Roberts ,but if your going to build a 257 Roberts us a 7 1/2 twist barrel and does a 257 Roberts shoot well with a 7 1/2 twist barrel

280 would be nice.

Go with the 7x57. I am building one for my daughter on a Mauser action.

Was never a question in my mind. 275 Rigby. I reload and it will take care of my shooting and hunting needs.

Putting a 280 Remington cartridge into a custom Winchester rifle?

No no no no..

7x57 or 270 Winchester

I built a m70 in 6.5x55 didn't feed very well, changed to a mauser follower, now feeds slick as snot on a door knob.

Off topic here, but a tip I got years back from Chick Donnelly regarding feeding. He had a flat plain follower that he used with quick set epoxy to 'mold' or shape different follower ribs and tapers to address feeding isssues on cartridge change bolt guns. His advice, always try adjusting the follower first, adjusting the feed rails is a perilous business and remedied only with a great amount of time and labor if it goes sideways. First thing you hear on the forums if a guy has a feeding problem, adjust the feed rails...bad advice, generally.

7 Mauser should work fine with some tweaking

What tweaking would it need?

35 Whelen would be skookum. Go contact dpcd on accuratereloading.com and he will sell and install a nice new Dougie barrel in any contour you please including a 1951 contour Winchester barrel for 275 bucks if memory serves. Throat that puppy for a 250 grainer and sally forth!

I can't see how any short action would be a good choice for a 7x57, as the magazine length would limit the COAL with many, maybe most, component bullets. Pre-'64 Model 70s are all long actions, so 7x57 would be a great fit with all bullet weights/lengths.

What is a dougie barrel? Never heard of that brand?

Douglas

Pick another action with decent gas venting in case of primer rupture.

Douglas blanks cost 250 plus so paying 25 for installation seems pretty cheap.

Like free labor cheap.

Im guessing thats plus the cost of the blank-

Bingo........

There's a reason why they cost $250...

It's also the reason I refuse to install one.. Just me.. YMMV...

I have only fit one Douglas a Savage 99 in 219 Zipper Imp. It shot in the .300 range fireforming never did hear what it did with formed ammo. I have another Douglas coming for a Montana action so we will see. Fit a bunch of Schilen barrel and had good luck with them. Several other manufacturers,

Redneck what barrel do you prefer?

I have built both 280's and 7x57's on pre-64's and like either one. My choice though, would be a 7x57. A truly great cartridge. I would choose whatever barrel I liked. I like Douglas contours but am not too particular regarding make. I can alter contours. GD

Red eck put a pac nor barrel on a Winchester for me once. Excellent barrel. Like I said, if I call up dpcd on AR and send him 275 bucks I get a Douglas barrel contoured the way I want 8nstalled on my rifle a d they shoot better than I can.