Rifle Scopes Scope mounting screw confusion?!?!

[CleanMoostang]

So teach me a little about what it means when I look at mounts and it says 8-40 screws, etc. And what the screws for the rings are all about?

Looking for a 30mm scope mount and rings is why i am asking.

ETA: Rem700 SPS 308

 

[AKAce]

Re: Scope mounting screw confusion?!?!

8 / 32 is the Size of the Screw. #8 with 32 TPI

 

[egw1]

Re: Scope mounting screw confusion?!?!

Many / Most bolt action rifles, Remington, Winchester, Savage typically use 6x48 screws to attach a scope base to there rifles. 6x48 is a special thread not the normal 6-32 or 6-40 pitch.

A number 6 screw is about .138 in diameter. the second number is the number of threads per inch. The Hole most drill to tap for the 6x48 is a .120 diameter hole.

8x40 is larger and thus stronger all things being equal. Remington for the 6R and other rifles has started offering there rifles drilled and tapped for #8 Screws. These are about .026 larger or .165 in diameter. the hole in the receiver will also be larger.

Someone may have a comprehensive listing of all guns that are now drilled and tapped for #8 screws. IF you can measure the hole size it will be in the .145 range.

geo

www.egwguns.com

 

[CleanMoostang]

Re: Scope mounting screw confusion?!?!

So for a Bushnell 4200 with a 44mm objective would a EGW one piece rail that is 20moa and burris medium low extreme rings work for my set up? I am just worried that I will have my scope touching the barrel