Another Q for JBelk
Mr. Belk,
I was reviewing some of your files & pictures of polishing the M98. I have a question regarding the rear bridge. I was told it is ok to remove as much as .010" in material. Then I noted that in the picture of making a scope base you say the radius will be .585". Well, I measure 3 of the VZ24's I am working on and none had a radius near that. I measured from the top of my mandrel (.700") to the top of the bridge. I added that to 1/2 the diameter of the mandrel (.350") and the largest radius I got was considerably smaller than what you mention, about .020" less. I removed no more than .005" from any of these receivers. Is this normal or am I doing something seriously wrong here???
05 March 2003, 17:31
<JBelk>z1r---
The radius will be correlated to the differential of the mounts......
Dang, that sounds technically important!!
The goal is to have the top of the mounts come out level and parralel to the bore.
If you're going to make mounts, like I do, it makes no real difference what the differential is because the mounts will be trued with the bore as part of the process.
SO-- From the top of the rear mount to the mandrel, plus half the mandrel, should equal top of the front mount to the ring, plus half the ring...If those measurements are the same the mounts are parralel with the bore AND with each other.
Thanks Jack!
I originally posted at work and when I got home measured 6 different surplus mausers. It really is amazing how each one is different with regards to rear ring height. Its a wonder that anyone can actually use the commercial bases. I guess I will indeed have to start (trying) to make my own.
The other thing I noticed, which you've pointed out before, is how unlevel, uneven, or unparallel the two flats can be. How much material is generally considered the limit that one can remove from the rear ring in any given spot? I was told .010" but I'd really like your opinion.
Thanks,
Mike
05 March 2003, 20:01
<JBelk>z1r----
There's about .065 of steel that makes up the bolt stop (rotational) surface just behind the extractor cam.
Several times I've had really nice actions that had been ground down into ruination dimensions on the rear bridge and lost that stop. I made a square bridge that covered the WHOLE bridge and looked like an old commercial square bridge but the entire surface was actually screwed and soldered to the old bridge to make up the material I ground off to straighten up a butcher job.
With a rotary table, boring head, and a long 3/8" end mill you can make six "bridge caps" at a time!!
I like one piece commercial scope bases. You can shim the front or rear to mount them stress free and straigt without having to lap rings, locktite screws or increase the screw size.
I like things that are STRAIGHT and SOLID and SQUARE. When you grind a Mauser and see one that's actually straight it's a semi-religeous experience.
BTW--- Measure a few RemchesterRugages, they're crooked, too !!!
[ 03-05-2003, 11:09: Message edited by: JBelk ]Thanks Again. At this rate I should finish my project by spring 2023.
![[Wink]](images/icons/wink.gif)
06 March 2003, 15:08
CraftsmanJack
Remember the good ole days when Redfield made one piece mounts with a recoil shoulder?
I am still hoarding a few for special projects.
07 March 2003, 06:49
<JBelk>Craftsman---
Yes I DO!!
All this crap about locktite, 8x40 screws and other patches are only making up for the lack of design and workmanship. If a mount is well made and designed there's NO need for the patches and compensation of extra stuff.