Picatinny rail drawing

[mcskipper]

Hi Guys,

Just stumbled on to a drawing of the Picatinny Rail Mount.
This is also a Weaver mount, but the groove dimension is .180" for Weaver

http://www.wikipedia.org/wiki/FileM1...ossSection.svg
Part way down the page.
Double click on the box & it will go full screen.
It can also be found under Mil Spec M1913

I've been making my own scope mounts for years & this drawing would have saved a lot of time checking mounts I had on hand.

Did take the time after I made a few to make a gage. That was a BIG time saver.

How close did you guys get w/ your drawings?

[Ken_Shea]

Had the correct dimensions so it was not a problem.

The link seems invalid, link to the drawing.

http://en.wikipedia.org/wiki/File:M1...ossSection.svg

[38_Cal]

Here's a link to the Brownells website tech department article I wrote for them several years ago, before they declared me "excess" to their needs. This not only gives the cross section, but the slot spacing and dimensions, which are also critical to the design.
http://www.brownells.com/.aspx/lid=1...he_Difference_

[Boucher]

What is the best sequence of cuts to make one of these on a milling machine? I made one on the top of a one piece barrell bedding block. I need to do another one.

[Ken_Shea]

What is the best sequence of cuts to make one of these on a milling machine? I made one on the top of a one piece barrell bedding block. I need to do another one.

Byron, not sure it makes any difference really.
I usually face to needed thickness, drill, use a 90 deg double angle for the 45 degree and then the slots.

[mcskipper]

I set the mount in the mill on it's side.
Make the cuts that make the.617"
Do the two 45's.

Note:
I found that most rings did not have a perfect 90 Deg. all the way to the bottom of the rings.
So I will always knock .010" off so that if you looked at the side of the mount there will be a small flat.

If you are going to make a number of these (And you will) I made a tool like a fly cutter with an index carbide insert.The insert is set so that I can get the 45 Deg. with out having to move the mill head off tram.