Drilling the fourth hole for scope mounts on a Rem 600

[bat119]

I want to change my scope mount from a one piece to two

What size drill bit and tap do I need?

I have Leupold detachable rings with a weaver base, what bases would I use Rem model 7?

Cheers
Rick

 

[ronnie01]

What is the screw size??

R

 

[double gun]

Yes model 7 bases is what you want. As Ronnie asked, the tap drill size is dependant on the screw size you're hoping to use.

 

[tiriaq]

6-48 is standard, #31 drill.
I have never seen a 2 piece Weaver base set for a 600 or 7. Does Weaver make them?

 

[Lodi]

There is/was a 4-hole version of the Model 7 introduced in the late 90's, so Weaver did produce a set of 2-piece bases, #421M for the rear and a standard #35M for the front.

But IIRC, the receivers were slightly different on the 4-hole version, at tad longer where the base fits.

 

[JJ-65]

Weaver makes the two piece bases in steel also

 

[double gun]

The model seven receivers were not changed, the rear bridge length was not altered. The only difference was the 4th hole added.

 

[Lodi]

The model seven receivers were not changed, the rear bridge length was not altered. The only difference was the 4th hole added.

Thank you. Too many guns and too much stuff to remember off the top of my head.

 

[bat119]

Thanks for the replies I have a machinist buddy doing the hole for me, I'll round up some model 7 bases

 

[Why not?]

You really do not need to drill a fourth hole.

I have used a rear base with a single hole and epoxy between the base and the bridge for years without ever having one budge, even on the heavy recoiling 35. Just need to have the base and receiver clean, but release agent in the screw hole and on the screw threads.

If you need to remove the base later, just turn out the screw, heat the base with a hot clothes iron for two minutes, and presto it will come right off.

Ted