Gunsmithing scope base hole drilled off center?

[Cory Lee]

I bought a 700 a few months ago. Came with Leopold one piece base with rings. Took the rings off and the front screw was broken off under the ring. Had the gunsmith drill it out and tap to 8-40. He was off center. The Badger base doesn't line up with the front hole (closest to barrel.) He says its not a big deal. What do y'all think?

Thanks.

ETA: I had him redrill all 4 holes to 8-40. It is too far forward to even start the screw in.

ETA # 2: Thinking about it, the screw broke off in the 3rd hole back. The off center hole is the 1st hole. All others line up. The Leupold 1 piece lined up before, now the Badger doesn't.

 

[Hink]

Re: scope base hole drilled off center?

If the threaded hole in the action is far enough off that the screw won't thread in, then I say it is a big deal. I'd hit the 'smith' that did the work and request a refund.

Either way that works out, I'd find a good smith to fix what the hack balled up. What is possible is to red loctite an 8-40 screw in place, mill off the screwhead, then drill and tap the receiver in the correct location. Then bed the rail to the receiver and never take it off.

 

[Cory Lee]

Re: scope base hole drilled off center?

Thanks for the advice hink.

 

[Barrel Nut]

Re: scope base hole drilled off center?

If you're going to go that route, I'd clean the screw and the hole with acetone then devcon the screw in. Make sure to first.dry fit it to keep from running the screw in to far and interfering with the bolt.

 

[Jkob]

Re: scope base hole drilled off center?

I find it hard to believe the smith was at fault. Even a dummy could drill out an existing hole to a bigger size and not have it out that far; the drill will follow the old hole and maybe run out a bit, but not that far.

 

[Keith Johns]

Re: scope base hole drilled off center?

He hopefully used an end mill to "drill" out that broken off screw. Probably just didn't indicate anything in(although I don't see why its so hard to come down on top of a screw).




I wouldn't epoxy your base onto your action. It will probably need to come off one day.


If 3 of the 4 holes are fine, and opened up to 8-40, personally I'd open the one thats off up to the next size I could use and avoid the glue.



Hell before I glued it, I'd consider having a good welder plug the hole and then have it re-cut correctly by someone reputable on here. I think welding it shut would be an option, but then the action threads would have to be chased a well. Not a quick fix but maybe the right one.

Epoxying a screw in place, milling/sanding it down, then re-drilling/tapping is an option <span style="font-weight: bold">if</span> the hole is far enough off.


Perma-epoxying it on there would be my last choice. Id try to get it fixed. I think a tig welder could fill that front hole without hurting anything. Then a good machinist could cut it up/clean it up right.

 

[Barrel Nut]

Re: scope base hole drilled off center?

I didn't think anyone suggested epoxying the base on. What I suggested was to devcon the screw in, mill off the head and re-drill. That would be preferable to welding because you wouldn't have to worry about warping the action with heat. With three 8-40's already holding the base the forth being drilled into devcon wouldn't hurt.

 

[Greg Langelius *]

Re: scope base hole drilled off center?

If I read your edit right, the problem has already been resolved by the Smith. Assuming the fix worked, I think it's the right one.

Greg

 

[Cory Lee]

Re: scope base hole drilled off center?

I thought about it and the hole that is off center isn't even the hole that the screw was broken off in. It had to be drilled out of the third hole back. He messed up the first hole. It did have a Leupold 1 piece base on it. All holes lined up then. I don't have that base anymore to double check, but the new Badger base doesn't line up with only that hole.

 

[cal50]

Re: scope base hole drilled off center?

Simple machine practice gone bad but fixable.

If the screw was removed before drilling the drill would follow the existing hole. If he tried to drill on top of the screw its likely the screw was harder than the surrounding metal and the drill will deflect and go off center.

Using a carbide spot drill, drill or end mill to remove the old screw should have been the 1st line of attack. Moot point now but I would not let him have another crack at my rifle.

Since he said its "no big deal" I would let him open the base mounting hole up to fit the hole he put in the wrong location. He should be willing to fix his mistake and I would want the use of all my mounting holes.

 

[hero's machine]

Re: scope base hole drilled off center?

I would cut my losses before there is a 1/2-13 bolt on top of my action.....afterall, its no big deal.

 

[CaptLink]

Re: scope base hole drilled off center?

You have two choices one good.First find a smith that knows machine tools not many around,then get a custom base and have the holes drilled in the base in the same location as the current receiver mounting holes.It will be as solid as it gets.Number two best as long as the # 3 hole is not to far off have all three holes opened up to 10x32 or 10x40 on the center line that way its perfect.If I botched a job like that I would have fixed it right or bought you a new rifle.Find a better smith good luck