700 scope base tap?

[NC/Br Shooter]

I have a short action that needs scope base holes rethreaded. I understand that I should go to the next size above factory drilled.
What is the drill bit size,and tap size I need?
And where can I order the tap?
That's the biggest part ,where to find the tap.
The hard ware around these parts just don't have anything this small.
Thanks for looking and any advice!!;;;;!!!!!!!!!!!!!!

 

[LVLAaron]

What size are they now?

You don't want hardware store taps for stuff this size anyway. McMaster-Carr generally has good stuff. I prefer MSC Direct.

 

[Dusty Stevens]

8-40 tap and a #28 drill. You can buy the correct screws from brownells

 

[Edd]

I have a short action that needs scope base holes rethreaded.
Thanks for looking and any advice!!;;;;!!!!!!!!!!!!!!

GUNSMITHING SERVICES: 8-40 base hole receiver threading

An unfortunate side effect of production-grade receivers is the tendency for certain features to be machined slightly out of position. Our 8-40 optic base hole upgrade is intended to resolve this issue, additionally, it can also add base holes to receivers that were not originally machined for...

www.longriflesinc.com

 

[AlNyhus]

I have a short action that needs scope base holes rethreaded. I understand that I should go to the next size above factory drilled.
What is the drill bit size,and tap size I need?
And where can I order the tap?
That's the biggest part ,where to find the tap.
The hard ware around these parts just don't have anything this small.
Thanks for looking and any advice!!;;;;!!!!!!!!!!!!!!

Having done quite a few of these, my advice is to not just simply enlarge the existing holes and tap as they are rarely in line. The best bet is to have them done on a mill where the hole position can be corrected. Your optics will thank you for it.

Good shootin' -Al

 

[butchlambert]

Having done quite a few of these, my advice is to not just simply enlarge the existing holes and tap as they are rarely in line. The best bet is to have them done on a mill where the hole position can be corrected. Your optics will thank you for it.

Good shootin' -Al

Al is correct. I had my tool grinding shop to grind a 2 flute carbide end mill to enlarge and locate properly the holes for the base.

 

[GenePoole]

GUNSMITHING SERVICES: 8-40 base hole receiver threading

An unfortunate side effect of production-grade receivers is the tendency for certain features to be machined slightly out of position. Our 8-40 optic base hole upgrade is intended to resolve this issue, additionally, it can also add base holes to receivers that were not originally machined for...

www.longriflesinc.com

Chad does good work. He lines up the action to the raceway (just like we do for action truing) then thread-mills each hole to 8-40 at the proper place.

 

[WSnyder]

I agree with the others. Rem 700’s almost always have at least one or more holes out of place. Send it to someone with the fixtures and tools to do it right.

Holland’s fixture, 9/64 end mill, 8-40 tap.

 

[AlNyhus]

The last 700 I did, the front base screw hole and the very rear base screw hole were within a couple thou. of each other. The other two were .010 and .015 out. Normally, the rear holes are the worst aligned on the ones I've done. That may have to do with the rear bridge area being hand profiled at the factory. Not sure how the later CNC'd receivers are in this area. -Al

 

[WSnyder]

^^^ I found the rear bridges on many of those later RR’s to be really good and fit tight without that left rear corner roll-off. The one in the picture above is near perfect and won’t take much bedding at all. The rear bridge is maybe .002” low and hardly any difference from one side to the other. It’s so close that you could probably just bolt it up with no alignment issues at all. This one also took very little in the way of truing cuts to action and bolt.

 

[NC/Br Shooter]

Thanks for all the input.
I found a 8-40 tap and 4 8-40 skrews.
Fixed it for 20$

 

[Silo1616]

Thanks for all the input.
I found a 8-40 tap and 4 8-40 skrews.
Fixed it for 20$

Don't forget the tooling for the base(s) or rings (if integrated type). The standard 700 #6 screw holes will need to be reworked to accept the #8 hardware

 

[NC/Br Shooter]

Don't forget the tooling for the base(s) or rings (if integrated type). The standard 700 #6 screw holes will need to be reworked to accept the #8 hardware

Thanks for the tip.
The pic rail is on the action now.
I did have to swing by a a smith and he happened to have a few 8-40 skrews,
I ran the tap through the rail, drilled the rail holes out for the skrew heads, then cleaned out the breech end of the action with the 1 1/16 tap and was done.
Originally I didn't know what size to tap out the holes, hence asking.
Thanks everyone

 

[therifler]

I have a short action that needs scope base holes rethreaded. I understand that I should go to the next size above factory drilled.
What is the drill bit size,and tap size I need?
And where can I order the tap?
That's the biggest part ,where to find the tap.
The hard ware around these parts just don't have anything this small.
Thanks for looking and any advice!!;;;;!!!!!!!!!!!!!!

Brownell ‘s