10-32 screws in your scope mount

[pig ranch deadeye]

Generally, I prefer to upgrade my scope mount screws from 6-48 up to 8-40. So I was wondering: Why not go all the way up to 10-32? If you hold and look at the 10-32, you see it it really is a hefty mother! I read online people do that for the Mosin Nagant. I suppose if you have buggered up the holes on a 8-40 rig, stepping up to a 10-32 would be the thing to do. Gentlemen, a penny for your thoughts!

 

[Wedgy]

At that point you will have to widen the hole for the screw head as well which can be tricky with a regular drill on a pic rail. I change all mine to #8's also and sometimes do not put a release agent on the receiver when I bed the rail. It comes off easy with a heat gun. On the big guns I will pin the rail to the receiver. Pretty easy to do, I think Shep gave great DYI instructions a while back.

 

[Wedgy]

From Shep

"Just pin it. I use a #31 drill bit in a drill press. Drill right through the base into the receiver. Don't go all the way through the receiver. I usually put them right between the mounting screw holes. After drilling this .120 diameter hole take an 1/8 drill bit and cut a few pins from it with a cutoff wheel. This is .005 bigger than the hole you drilled. One drop of red locktite and tap the pins in. A small chamfer on the bottom of the pin helps it start in. Practically anyone can do this. These pins are much stronger than screws. I do all my actions like this. Go to 8-40 screws and pins. All on a bedded base. No more problems.
Shep"

 

[tobnpr]

Generally, I prefer to upgrade my scope mount screws from 6-48 up to 8-40. So I was wondering: Why not go all the way up to 10-32? If you hold and look at the 10-32, you see it it really is a hefty mother! I read online people do that for the Mosin Nagant. I suppose if you have buggered up the holes on a 8-40 rig, stepping up to a 10-32 would be the thing to do. Gentlemen, a penny for your thoughts!

Fair question...
I've installed over 200 of the Rock Solid mounts you refer to on MN's.
No reason I can think of not to...other than it might just be overkill. Never really thought to ask Ken at Rock Solid why the #10, and not #8- but I suspect it's because they're usually thought of as more of a "DIY" amateur drill and tap mount (I use a mill and DRO, natch)- and it's a lot less forgiving using a #8 tap in a hardened receiver than a #10. Believe me, I've "fixed" more of these botched "I can install the scope mount myself with a hand drill" than I care to think about.

I've never felt the need to go over #8 on magnum mounts, don't think it's needed- but see no reason why it couldn't be done if that's what you like...

 

[pig ranch deadeye]

The 10-32's are sounding better and better!

 

[LoneTraveler]

There are 10-40 gun screw and taps too. Finer threads gives a few thousands more diameter to the screw shaft itself. Little more pressure on hold itself. I would only use No. 10 if for some reason 8-40 threads got damaged and needed cleaned up. Pinning gives a lot more stability with less work too.

 

[pig ranch deadeye]

There are 10-40 gun screw and taps too. Finer threads gives a few thousands more diameter to the screw shaft itself. Little more pressure on hold itself. I would only use No. 10 if for some reason 8-40 threads got damaged and needed cleaned up. Pinning gives a lot more stability with less work too.

Can you please explain pinning? I am not familiar with that.

 

[Blackhawk]

Generally, I prefer to upgrade my scope mount screws from 6-48 up to 8-40. So I was wondering: Why not go all the way up to 10-32? If you hold and look at the 10-32, you see it it really is a hefty mother! I read online people do that for the Mosin Nagant. I suppose if you have buggered up the holes on a 8-40 rig, stepping up to a 10-32 would be the thing to do. Gentlemen, a penny for your thou

Generally, I prefer to upgrade my scope mount screws from 6-48 up to 8-40. So I was wondering: Why not go all the way up to 10-32? If you hold and look at the 10-32, you see it it really is a hefty mother! I read online people do that for the Mosin Nagant. I suppose if you have buggered up the holes on a 8-40 rig, stepping up to a 10-32 would be the thing to do. Gentlemen, a penny for your thoughts!

The more TPI that a thread has the more purchase power or holding power that is obtains. Even though the diameter of the screw may be larger the reduction of TPI will negate the use of a larger diameter screw with less Threads Per Inch.

 

[pig ranch deadeye]

Ok, so 10-40 seems to be the way to go.

 

[Wedgy]

Can you please explain pinning? I am not familiar with that.

See post #3 for pinning

 

[pig ranch deadeye]

From Shep

"Just pin it. I use a #31 drill bit in a drill press. Drill right through the base into the receiver. Don't go all the way through the receiver. I usually put them right between the mounting screw holes. After drilling this .120 diameter hole take an 1/8 drill bit and cut a few pins from it with a cutoff wheel. This is .005 bigger than the hole you drilled. One drop of red locktite and tap the pins in. A small chamfer on the bottom of the pin helps it start in. Practically anyone can do this. These pins are much stronger than screws. I do all my actions like this. Go to 8-40 screws and pins. All on a bedded base. No more problems.
Shep"

What is ä bedded base" ?? I am not a gunsmith...

 

[shortgrass]

Ok, so 10-40 seems to be the way to go.

There is NO logical reason to go to 10-40 screws! If 8-40s won't hold it, I'd not want to fire that rifle from my shoulder! From the reading your posts, you need to find yourself a reputable gunsmith. Learning off the interdnet often leads to disaster and/or unnecessary modifications. You put 10-40s in a receiver and you have immediately destroyed the value that receiver has or had. Folks will look at that and assume the threads got messed-up and wonder what else is wrong. 10-40s for the sake of 10-40s is amauture stuff.

 

[Wedgy]

What is ä bedded base" ?? I am not a gunsmith...

Many people bed the base/rail and rings also.

 

[pig ranch deadeye]

There is NO logical reason to go to 10-40 screws! If 8-40s won't hold it, I'd not want to fire that rifle from my shoulder! From the reading your posts, you need to find yourself a reputable gunsmith. Learning off the interdnet often leads to disaster and/or unnecessary modifications. You put 10-40s in a receiver and you have immediately destroyed the value that receiver has or had. Folks will look at that and assume the threads got messed-up and wonder what else is wrong. 10-40s for the sake of 10-40s is amauture stuff.

Thanks for recommending caution. I appreciate your advice.