Suggestion for "fixing" a loose dovetail?

[tobnpr]

My son called asking my advice on how to best "fix" a loose dovetail.
He's got a beautiful Sharps .45-70 and just bought a Hi-Lux period correct long scope for it. Shoots lights out- three holes touching at 100 yards, blew me away...

Problem is one of the dovetail mounting blocks is very loose- either the female barrel cut or the male block from Hi-Lux is out of spec. Pic he sent isn't great- but you can see quite a bit of daylight underneath, only about 1/3 of the dovetail is engaged at the top when he tightens the set screw.

He's going to call Hi-Lux to see about a new block in case the one he has is out of spec; if it's the barrel I'm going to have fun machining my first one to fit. In the meantime, what is the best way to deal with this? My thinking is shimming both sides is best (as opposed to the bottom) to get maximum contact engagement?

 

[C.E.Smith043]

I'm assuming that is a set screw or some type of screw going thru that's pushing the sight block base upward?

 

[AlNyhus]

How about shimming the sides with cut strips of a feeler gauge?

 

[Will Henry]

SOP, for rifles which are not a very nice Sharps, was to lightly peen the edges of the female dovetail. I would not do that on this one. On this, the best move is to make a new block. Otherwise, shimming the sides might work out ok. WH

 

[dellet]

The reproduction rifles have different size dove tails. Some use the standard moderns size of .375 others, mostly US made, try to use original sizes, some who knows the size. Measure both front and rear to get the correct size for the rifle. They can be different sizes. Hilux has a chart that may or may not be correct for application, but does list the sizes offered.

Sliding Mount for Malcolm 6X Long Rifle Telescope

If you’re looking to mount a Malcolm 6X long scope on your rifle without drilling and tapping or if you’re looking to shoot hot loads with heavy bullets with your Malcolm scope, you’re in the right place. The Malcolm Sliding Mount indexes into the front and rear sight dovetails on the rifle...

hi-luxoptics.com

 

[tobnpr]

SOP, for rifles which are not a very nice Sharps, was to lightly peen the edges of the female dovetail. I would not do that on this one. On this, the best move is to make a new block. Otherwise, shimming the sides might work out ok. WH

He mentioned he had read about peening the sides, but we both discounted that for the reason you mentioned. The blocks for the rear sight come in either .375 or .500, his is .500.

We'll shim the sides with brass stock until the proper "fix" (new block) is ready. Thanks

 

[tobnpr]

I'm assuming that is a set screw or some type of screw going thru that's pushing the sight block base upward?

Correct. These are a bit different because the only firearm dovetails I've encountered are sight dovetails which are snug enough that they need to be drifted, these are designed to be easily removed to replace the sights when desired, but no idea how much slop there's supposed to be, this is obviously too much.