Pic Rail Contact

[Nxian]

Hello All,

This is my first post, but I've been around for years. The 6mmbr site got me into shooting and reloading - then I had kids (3). I'm about ready to jump back in (I've really missed it!)

I'm posting to ask a question about the way different scope rings mount to a pic rail. Attached is sketch of the cross section of a rail. The dimensions/tolerances are from the 1913 standard. My question is this - The way the rail is toleranced indicates to me that the ring base should make contact on the angles (yellow), yet many designs make contact on the top of the rail (orange). The yellow surfaces are controlled with the .748 +/- .002 dimension, while the top can be as much as .02 under and still be in spec.

In your experience, does it matter?

 

[Walt Krafft]

Nope

 

[Nxian]

Thanks for the reply Walt.

Anybody else want to chime in? I know it's kind of trivial, but it appeals to my OCD side that the center of the ring doesn't shift based on the rail height if you use the contact surfaces in yellow.

Getting ready to make a one piece mount soon and ran into this while designing it.

Tim

 

[NZ_Fclass]

The taper will centre the rings. Yes -contact on the 'yellow" would be best, but, honestly, I have never looked. Nor has a scope fallen off and all hold zero for months.

 

[Nxian]

I decided to go with clamping on the angles (yellow in diagram). I agree that it doesn't matter.

I have a design for the mount. Going to be a one piece.

I went ahead and made the easy part (the rail!)

 

[Nxian]

And here is the finished product (before anodize)

I'm pretty happy with it.

The rifle is a savage action with a pac nor barrel in 6BR. Excited to get it out again!

 

[Nxian]

 

[Nxian]

 

[SEGARE]

Even if it doesn't show any improvement in groups, it is certainly a work of art. I'm jealous of your skill and machinery.

 

[CJ6]

Nice lookin........Do you have a pic of the ends and right side ?

 

[shoobe01]

Worth looking up the standards, as there are a couple that address this exact question. Picatinny uses side clamping, and then is a bit fuzzy about how it interfaces with the crosscuts so is only sorta truly as specified.

The (very similar, broadly backwards compatible) NATO RailGrabber improves on this by being a three point of contact system, uses the top rail as one specified part, and more surface area, I hear, but now we're at the edge of my understanding of why that's all good.

 

[Ccrider]

Impressive machine work. It’s got to shoot!!!

 

[Dusty Stevens]

You should make and sell those rings. I like it

 

[Nxian]

shoobe01 - Thank you! I had the 1913 standard but was completely unaware of the NATO spec. This was the information I was looking for with my original post. It looks like they cut the tolerance from the bottom angle to the top surface in half to better accommodate that style of mounting.

 

[Nxian]

Thank you everyone for the kind words about the mount. I work primarily for the automotive industry - All I usually hear is "not fast enough" and "too expensive".

 

[Nxian]

CJ6 - here are a couple more pictures.

 

[Nxian]

 

[Nxian]

 

[boltfluter]

And here is the finished product (before anodize)

I'm pretty happy with it.

The rifle is a savage action with a pac nor barrel in 6BR. Excited to get it out again!

View attachment 1317648

That is a work of art! Tell us what kind of mill you run and the software that you like.

Paul

 

[CJ6]

So.....When are these going into production ?????