what is the safest depth to drill scope mounting screws

[corey012778]

would be shocked if it was not metric.

[Ballistics in Scotland]

If the depth of hole is critical, and it looks likely to be here, it is a good idea to grind the end of a tap flat, right back to the complete crests. You can't start a hole with one in that condition, but it will deepen the usable thread available in one you have tapped as far as you can get with a bottoming tap.

I think the coarse thread in the American, British and metric systems are the strongest, when the hole is in good steel. Make the pitch finer, and the threads will strip first. Make it coarser, and the screw will break in two. The reasons to use a finer pitch, such as 6-48, are to give greater mechanical advantage and resistance to vibrating loose, and perhaps to stop people using a screw in inferior metal, which used to be commoner than they are today.

[corey012778]

yeah they where metric screws did not even look at any sae screws until I was done gathering.

[corey012778]

I cut the notches in the base for a retaining pin. a hand drill, started with a bit the size of the holes in the barrel. pin would not go thru moved up one size. I am just missed alined by a shade. can't find my round file at the moment. when I do I should be able to fix that in no time.

[LAGS]

I think you have it this time.
Give that a try, and then see if you still need to go to the trouble of drilling and Tapping the barrel.
BTW.
A Black Felt marler will touch up that shiny bare metal , there is no need at this time to refinish the whole scope base

[corey012778]

may end up making a pin. the sight pins are just long enough but I would like to have one a little longer. meet edge to edge of the base.

[LAGS]

I cant remember, but I think a 4/40 screw will fit thru the hole in your barrel.
If you can find one long enough, you could put a nut on the other side.

[corey012778]

Thought about that, have two places to look. Right across the street from each other. There on my way home so I can check,

[corey012778]

made the indentation for the set screw feels like I need to go a touch deeper. I used a cordless drill to do the work. lower power then a corded drill. better feel then on depth, for me, then a drill press.

[LAGS]

You should have blackened the top of the Dovetail flat with a Black Marker first.
Your mark or dimple would show up way better.
Was that marked thru the hole in the scope mount ?

[corey012778]

Yes, cleaned it off and marked 3 times, the set screw hole on the mount is off center when the base is fully tighten.

[LAGS]

That can be normal for the base to be off center, because it has one fixed clamp and one moveable clamp , correct.
If it has two movable clamps, then it can be centered more easily, and you would mark the true center of the barrel dovetail, drill and tap that hole, and then center the two clamps to make the base more centered.
But no harm for this type of scope to set off to one side.

[corey012778]

One clamp.

[LAGS]

People dont realize that those clamp on mounts are not always Centerline of the barrel.
But if you were going for real precision shooting, then they would be buying a more expensive mount.
But they do work, and work good, even offset to one side.

[corey012778]

inside a 6in paper plate (distance depends on the gun) is all I will every ask for out most guns, anything smaller is on me.

went with the screw idea. bought too long of a screw. may get a shorter one or just cut the ones I have. be cheaper to just buy the shorter one. few cents vs a few dollars.

[LAGS]

You should be able to keep all your shots on a 6" paper plate at 300 with that rifle and handloaded ammo.
I think you would need a higher power scope to get much less at that distance.
But the rifle will probably be capable of it no problem off a rest.

[leadman]

I just used a set of Weaver scope mounts for the grooved 22 LR barrels on my Mosin Nagant. I don't shoot mil-surp ammo though.

[corey012778]

I have shot the last of the mil-surp I had. for some reason I can't find the factory ammo. guess I just have to load some cast up. lol

[LAGS]

What powder and boolits do you plan to use ?
My MN's like cast

[corey012778]

I have the lee c312-185-1r. have varget on hand. but no load data for it. so I am going to some homework and get the powders. need to get some rifle primers. only have pistol primers right now.


sorry would of replied sooner, hit the busy part of the week for me. bowl two leagues, then my wife makes plans for all weekend.