S&W 52-2 w/Ultradot .. POI too low

I purchased a 52-2 at a show recently, I was hoping to find one after being exposed to one at BE practice day at our range, and sure enough I did.

It came with a Wilson Combat frame mounted sight rail, and an Ultradot sight, 2 steel follower magazines and original stocks. 

In my first sight adjustment exercise, I was unable to bring the POI up to the X ring, in fact several inches low even on the short line.  Thought it might be the sight, so I replaced it with another one I had.  Sadly, on my next trip to the range to sight it in, I am still unable to raise POI ... turned the adjustment screw until it showed the rubber gasket.

SO ... I am wondering if there is a way to 'shim' an ultradot in it's mount?  The frame rail mount with 5 screws per side would not seem to have the ability to be adjusted for height?  The mount to the rail of the rings doesn't really look like it would tolerate much in the way of a shim under it, and same with the rings to sight ... not a lot of leeway there.

I can provide photos if anybody things that would be a benefit.  I love the gun, am fully stocked with bullets and brass to reload WC's, but until I can get it to hit the X, not much point.

Any clues appreciated, I am a relative newbie but have some enough smithing experience to do most of the work short of drilling the frame.

Thanks for any ideas!

-Kevin

More than likely the frame mount was not mounted with 1 degree angle to compensate for the barrel locking up into the slide. 1 degree gives you approximately 0.017” per inch of rail. So if rail is 4 inches long, the drop would be approximately 4 x 0.017” = 0.068”. So not sure if you have enough meat on your rail to have 1 degree drop machined into it to get you zeroed?
I would look at that possibility first before shimming.
Jon

Hi Jon

Thanks for that synopsis... I was afraid it was probably an issue with the frame rail mounting ...

What would I need to measure to see if there's enough 'meat'?  I am not sure where the machining would take away material, but I am assuming the top side of the mounting 'angles' on the left/right side of the rail would cause the ring to locate lower, and hope the lower half of the clamp still has enough travel to clamp tight.  Interesting.

Thanks

Basically you need to remove approximately 1/32” minimum to 1/16” on the front of the rail and taper it back to the rear. Rear basically untouched/barely touched and the front reduced in thickness 1/32 - 1/16. Front cross slot might need recut deeper.
Jon

Before you go to all this fuss and feather, you might try a 20 MOA riser.  You might need to cut a new slot but this will give you nearly 1/3 degree to start.  There are also 40 MOA risers out there and that’s half way there.  


https://www.amazon.com/UTG-Leapers-MT-RSX20MOA-Elevated-Picatinny/dp/B01M1KP7PD

Would it make sense to put a .030 shim under the back ring just to verify the error, then take off .015 from the base and .015 off the bottom of the front ring?

there are companies who make shims for that...I had the same problem...solved with a shim

I would be inclined to try what I've been doing for years with smallbore rifles and Contenders, that is if your scope is a 1" tube. Burris Signature rings with the offset inserts take care of just about any elevation problem I have come across. Nothing moves on my heaviest recoiling Contenders. You can fiddle around with different inserts to get the correction you need. Just my 2 Lincolns.

Thanks for the multiple responses.  I did see the Burris Signature rings (but a poor job by the marketing department ... they need to better explain how they work)  With the suggestion, I dug a little deeper and found the replacement Pos-Align offset inserts so I ordered a medium height ZEE ring set for weaver rails, and a.020 offset insert for the 1" tube, which is what my Ultradots are.  I am hopeful this gives me enough adjustment without having to machine anything.

 Thanks for all the brain power found here to help this newbie, and I'll report my findings!

Cheers!  -Kevin

SUCCESS! 

The Burris ZEE rings, with an .020 Pos-Align insert raising the rear of the UltraDot worked perfectly.  Plenty of adjustment left on the vertical alignment at 25 yards...
I think the rings are very nice quality, cost effective and the ability to raise and lower both front and back (or shift right and left for that matter) is a great system.

Now, time to develop a load and practice with the 52-2.  Thanks to Doug and all that helped me out with ideas!

Cheers

-Kevin