Weaver mount for 1978 25-2?

I have a weaver mount for my K-frame k-22 that uses the one existing hole, slides over the frame and anchors in the groove for the elevation screw... Doesn't require any tapping of another hole.

Doesn't fit my 25-2 though. Want to find a scope base that won't require tapping a new hole like that... does anyone know who makes one? What Weaver model it would be?

they were advertised as fitting K L and N frames at one time, 

not sure if Weaver still makes them

bsquare was making one that used a saddle type front, that fit over the front of the frame, 
advertised as no mar, but they would

My buddy politely reminded me that it would be basically ruining the gun to mar it up with one of those mounts or get it drilled and tapped, so figure I'll use my 625 that's already factory drilled for a scope base to workup loads and hope they translate to the 25-2 as well.

Greetings,

If the cylinder throats of the M25 are the same as the M625, you will get similar performance (groups).

Some of the early M25 revolvers had large throats (0.455") and you are forced to use bullets sized accordingly.

Cheers,

Dave

Mines's from 1978. Not sure about throat size. I just know I haven't gotten any good groups out of it so far but the 625 does group fairly well with some ammo.

Greetings,

Remove the M25 Cylinder and pay a visit to your local Machine Shop.

Make sure the cylinder is "squeaky-clean".

Ask if they would kindly gauge the throats with a set of gauge pins.

Stop by the Donut shop on the way to show your appreciation.

Cheers,

Dave

+1 on Dave's comment.

You can buy individual gage pins from MSCdirect.com for about $3 apiece.  Get a half dozen from about .450 to .456 and you are set to measure all your 45 throats.  Cheap and useful long term for .45 revolver fans.  I also find them useful in fitting barrel lower lugs (.196-.202).

I have a 4" JM 625 that shoots well.  I like it. - 
Having a hard time measuring cyl throats with my cheap calipers, I did this:
Cylinder chambers clean I dropped .451" Noslers thru. All 6 chambers the Noslers passed thru with very light push w/ a dowel. Probably just squared the bullet up. 
Then I tried .452" semi-wad cutters. All 6 cyls required firm pressure or tapping with the dowel. -- -- 

Buzz steered me onto this: makes cleaning lead shooting revolvers a lot easier - for me anyway.
I was concerned but the mfr assured me it would not harm bores. 
http://www.big45metalcleaner.com/  
2¢-YMMV  --- Russ

You can slug cylinders with a soft swaged bullet.  Tap the nose of the bullet with a hammer to squash it a little fatter.  push it through and measure.