Misaligned scope block

[curls]

Well my acquistion of a single shot rifle which came complete with Unertl scope blocks threw me for a loop. It was pointed out to me that the forward scope block appears to have been hand drilled about 10 Degrees off to the right on the forward attached hole. I am trying to decide if I should Re drill "all" 4 Scope block holes ( both Rear and forward ) and move on , I could break traditon and use the crooked blocks, but use an adjustable (windage) scope block, but lose the use of My 20X unertl scope. Any other thoughts on how to remedy this problem would be appreciated.

[J. R. Williams]

My vote is to re-drill and tap new holes and retain the use of the good Unertl scope.
JRW

[38_Cal]

Curls, if you have a vertical mill there's another option...make a base to match the contour of your barrel with the holes drilled to match the crooked ones and the top and sides square with the world...matched to the rear base. Make out of crs and case harden when done. I made up a short term use cutter to do the "eyebrow" cut in the base, with the teeth hand filed. Took half an hour, including finding a chunk of drill rod close to the diameter needed and the necessary turning and heat treating. I wouldn't want to try and use it for a production run, but for a handful of bases that I needed for a similar application, it worked just fine.

David

[Rusty Marlin]

I'm with 38 cal on this. If you have the equipment make over size blocks and mill the dovetails into location while mounted to the barrel.

[Al Messer]

That's the key: machine the blocks while attached to the barrel!

[curls]

Thanks to All for the advice, I will attempt the adaption scope block using the mis-aligned drilled hole and the "correctly drilled" hole as the hold down. There is one small detail that the "new block"will have to be cut with a proper sized fly cutter or the use of a correct diameter end mill out on the mill, which is the shallow concave cut on the inside of the scope block to match the round barrel shape since this is a tapered round barrel, Standing the block up vertically in the mill vise and "ignoring" the offset drilled holes. I will machine a split tapered barrel sleeve to go with my barrel clamp to secure the barrel in the mill vise during the rest of the operation. making sure to level all surfaces (Receiver, Sharps Borchart, Barrel etc) the cutter for the eyebrow cut appears to be similar in shape to a dovetail cutter, but with a concave inner shape Look out drill rod, here I come!

[motorcyclemac]

Well here's my 2 cents worth.

If the holes were drilled with a hand drill chances are the thread engagement is quite poor as it would have likely drilled oversize for that tap.

I would put screws in those holes with red loctite and allow it to set. Cut off the heads and file off the remaining part of shank thus filling the holes. Now put the barreled action in the mill and locate for proper position of the new holes. I would locate the new holes such that one hole falls between the previous holes and one hole behind them. Once the block is installed it will cover the mistake holes and no body will know it ever happened.

Personally I would prefer to properly drill and tap so that I can use proper blocks in the right place. I have had people bring me guns to re-scope with better mounts. I have removed weaver mounts that have had the holes round filed to fit. Screw heads turned down so they will fit in a misaligned hole. Bell mouth holes. Holes tapped too shallow with only 2-3 threads engaged.

All in all I don't trust other's mounting jobs for the most part. I examine them close and if anything looks off the mark I re do it. I always fill old holes and file flush. Nothing more nasty than pulling a base off to find it looks like a mine field under there from all the attempted fitments.

Depending on the circumstances, If I find a bell mouthed hole with poor thread engagement, I modify the mount so I can go from a 6-48 up to an 8-40.

It's a shame some of the hack work that happens to guns. Guys take some serious guts attempting to drilling by hand and tapping freehand with tiny taps.

What ever the gun, If it has a Unertl on it, it deserves to be fixed proper.

By far my all time worst repair request was on a Savage 99. The rear hole was 1/2 a hole off center. The 99 receiver is hard and obviously the bit wandered on them. I had to fill that hole and up size the screw to fix the matter. After some fun doing spot annealing I finally won and achieved proper alignment and good threads. Often times people take scope mounting far too lightly. It is a serious matter that should be done right....or not at all.