Scope base screw size?

[petew]

What is the screw size for scope bases , Leopold bases came with mounting screws, and I only have 1 shot at picking the right size bit, and tap.
Thanks
pete

 

[tiriaq]

Probably 6-48.
Drilling and tapping a rifle for a scope mount is a serious job. Really easy to mess up if the proper tools and equipment are not at hand.

 

[freezer filler]

If you have to ask what screw size, you would more than likely benefit from letting a gunsmith do the work.

 

[petew]

Probably 6-48.
Drilling and tapping a rifle for a scope mount is a serious job. Really easy to mess up if the proper tools and equipment are not at hand.

So this means you don't know?

 

[tiriaq]

"Leopold bases came with mounting screws..." Usually Leupold bases come with 6-48 mounting screws. That is the most common size. What bases do you have?
You have the screws. Have you measured them?
Do you have the tools, equipment and skills to drill holes in a rifle receiver without botching the job?

 

[kawicrash]

Use a screw pitch and size gauge. They have them at Home Depot or hardware suppliers if you're going to get a drill and tap anyway.

 

[petew]

"Leopold bases came with mounting screws..." Usually Leupold bases come with 6-48 mounting screws. That is the most common size. What bases do you have?
You have the screws. Have you measured them?
Do you have the tools, equipment and skills to drill holes in a rifle receiver without botching the job?

I have the tools, and skills, but I do not have a thread gage here that goes small enough to measure what Leopold included with the mounts . they also filled the threads with Loctite.
I do not like to guess . It isn't rocket science to find center and match drill a receiver.

 

[tiriaq]

You don't need a thread gauge. Just measure the diameter. 6-48 is the most common size used; 8-40s occasionally. If they are #6 Leupold screws, they will be -48.

 

[Longwalker]

petew, a friendly word of advice, you must also use a "bottoming tap", not only a regular tap. They are available at Brownell's

 

[petew]

petew, a friendly word of advice, you must also use a "bottoming tap", not only a regular tap. They are available at Brownell's

Good advice, I usually grind a tap to be a bottoming tap if I don't have one handy.

 

[guntech]

Leupold scope base screws are made to fit the particular receiver they are made for... 6x48 by far being the most common. There may be an odd European rifle that is tapped metric. Some guys with more money re-drill and tap 6x48 to 8x40... quite unnecessary as properly fitted 6x48 screws will hold heavy scopes and accessories perfectly fine.

A plug tap and a bottoming tap are most useful... a start tap is only good on holes that go right through or are very deep.

 

[petew]

Leupold scope base screws are made to fit the particular receiver they are made for... 6x48 by far being the most common. There may be an odd European rifle that is tapped metric. Some guys with more money re-drill and tap 6x48 to 8x40... quite unnecessary as properly fitted 6x48 screws will hold heavy scopes and accessories perfectly fine.

A plug tap and a bottoming tap are most useful... a start tap is only good on holes that go right through or are very deep.

Thanks. It is going on a Mauser 96 and I will drill and tap a piece of scrap first before drilling the gun just to make sure it is 6/48 .

 

[maddtrappr]

A formula for machine screw diameter...Diameter = Screw Size # × 0.013" + 0.060" for example to find the #6 screw diameter 6 x 0.013 + 0.060 = .138