Anyone know the what the spec for the radius of the "flat" on the top rear of a factory Remington M700 receiver?

Thanks!

2" radius 4" diameter as measured off a 40X

KC,

Thank you!

Gives me a place to start cutting a test curve on some 1x1" 1018 for a rear custom mount.

It will be more then close if the factory didn't polish the crap out of the receiver.

I assume you have 1018 on hand but I would not use it as it machine like crap. If you want to cut down your machine time and polishing time use some 41L40 or some 12L14 Both in the annealed state are just as strong as 4140 in the annealed state.

Both can be had at Speedy metals online and by the inch. I use these guys all the time for specialty materials

As for fit
I've put some on a few actions and I get near zero gap. But I do like my bases to be a little smaller in radius then the action and let the screws pull it down a few thousandths to 100% contact or as close to 100% as you can get with a machine part.
Just don't make your radius larger as your base will roll around on the action and the outer edges will never touch.

And FYI the 1917 Enfield uses the same radius as the Rem 700 front ring diameter they just use it front and back. So it goes to show you where Remington got the dimensions from.

Be careful using leaded steel. Some of the guys I do stuff for won't touch it as it blues funny with their rust blue formulas. Others say they don't have an issue with it. I ask the. Bluer anymore.
Don

Good point

quote:

Anyone know the what the spec for the radius of the "flat" on the top rear of a factory Remington M700 receiver?

Depends how fresh the paper on the belt sander was when they made it.

If it's a one-off custom mount just measure what you're trying to fit the mount to, or maybe re-machine the receiver. Epoxy and shims are the SOP... let us know how it goes.

Specs from Weaver show that they use a 3.90" diameter cut.

quote:

Originally posted by roughone:
Specs from Weaver show that they use a 3.90" diameter cut.

Well that would make sense if the mounting surface is .5 wide the gap produces from having a smaller radius sitting on top of a larger radius is .00039" by my CAD program. Not enough to worry about in my book. thats why I said be sure you cut the base slightly smaller in radius then the receiver so the outside edges touch first and the base is pulled down by the screws insuring a near 100% fit.

quote:

Originally posted by jpl:

quote:

Anyone know the what the spec for the radius of the "flat" on the top rear of a factory Remington M700 receiver?

Depends how fresh the paper on the belt sander was when they made it.

If it's a one-off custom mount just measure what you're trying to fit the mount to, or maybe re-machine the receiver. Epoxy and shims are the SOP... let us know how it goes.

This is very true too.