Crest removal

[spec4 e4]

After you remove the crest on the ring of the receiver, do you need to have it reheat treated??

 

spec.4

[Vladymere]

After you remove the crest on the ring of the receiver, do you need to have it reheat treated??

 

spec.4

7542[/snapback]

 

No. Only the portions in contact with moving parts need to be surface hardened on a Mauser receiver. The exterioer of the receiver has no moving parts so it need not be cse hardened. Crest removal does not harm the surface hardening to the remainder fo the receiver so heat treating is not required

 

Vlad

[spec4 e4]

Thanks, I am removing the crest on my Yugo M48 and the lettering. But not the serial numbers. How many of you guys remove the crest??

 

spec.4

[roscoedoh]

I have removed one. I used a file and stones.

 

Z does it a lot. Here's an article he did for Mauser Central: Click Here.

 

Jason

[Guest Guest]

http://mfrc.sizzlyhosting.com/index.php?sh...c=1019&hl=crest

[Guest TONEY]

I stoned mine off. had to shim scope mount afterwards

[z1r]

You probably had to shim the scope mount anyway.

[spec4 e4]

I check some of my receivers, and found that the rear needs to be shim. Is this the nor?

 

spec.4

[z1r]

You have to remember that these were not made to be used with scopes. We are altering them to allow scope use. Thus, when made, front ring and rear bridge heights were not a critical dimension.

 

To a large extent you can control this by how you contour/grind the surfaces. You can often eliminate the need for shims by taking a little more off one surface to even things up with the bases in place.

 

But, shimming is more the norm on mausers than the exception. I think a lot of people like one piece bases because they think they don;t need to be shimmed.

[911rat]

I used a 2 piece Burris base on my .35 Whelen. The front ring was a couple hundreths higher than the rear base. I used Burris signature rings with offset inserts to compensate and as far as I can tell it worked like a charm. I figured not using shims would be more secure.

 

As far as I could tell though, there was never a crest on the front ring. It didn't appear to be scrubbed either.

 

On the rest of my projects I'm going to polish the receivers and leve the crests intact. They are very faint anyway and have not been scrubbed. I'm going to have them matte blued and the scope mount covers a large portion of the crest anyway.

[724wd]

where or how are you guys measuring to see how far off the scope bases are? off the bolt? the bottom of the receiver? barrel? help a guy out here...

[montea6b]

I think the best way is to use those steel bars that have been machined down to a pencil point to check out the alignment of your scope rings.

 

I went cheapo on my bubba job because I was using an inexpensive scope that already had a crimp from a previous mount. As such, I was not concerned with marring it, but hoped to ensure internal alignment. (which I may or may not have achieved!)

 

Anyhow, I bought the straightest piece of 1" hardwood dowel I could find and cut it in two. Clamping two different pieces in the respective front and back rings, I tried to discern any height difference or non-alignment with both the naked eye and a straight edge. I looked long and hard from all angles and couldn't see any deviation whatsoever. I butted the ends up against each other and tried running my finger along them to feel for any deviation.

 

I've heard that the human fingertip is capable of feeling extremely small deviations... to test this for yourself, try lining two feeler gauges up next to each other and see if you can feel the difference when running a finger from one to the other.

 

Frankly I was very surprised that I couldn't see anything as I had contoured the action with hand tools and expected to be way off. Now granted this was wood, and not precision finished steel, but I figured that I at least be able to detect any big differences. I'm certain that the machined bars would have revealed some misalignment, but I decided it was good enough for now...

 

I next placed the scope in the rings and snugged it down a bit, removed it, and inspected for any sign of uneven pressure on the outside of the tube. Again everything looked good so I tightened them all the way, and upon reinspection could still see no indication of uneven bearing points on the tube.

 

Probable not a good enough technique for precision work, and I'm not necessarily even recommending it, but that's what I did FWIW.

 

 

[z1r]

Measuring from the bolt can be ok but I feel it is better to measure from a mandrel. The bolt can sag at the rear due to the loose fit in the bridge causing a bit of error. Whereas the mandrel tends to be better centered in the bolt bore. Obviously, if the barrel is still attached, using the bolt is the easier method. This to be used to determine shim thickness needed to even up the bases.

 

Those scope alignment bars are nice to verify final fit and maybe more importantly to verify side to side alignment which is best fixed with ring inserts.

[724wd]

yeah, hadnt thought about those scope alignment bars... seems downright logical now... as does your info, z1r.

[Guest spec.4]

I recheck the mounting on the receiver. I found that all of my receiver needed to be shim. But no in the back, just the front. I used an level and an file that is flat. I check the area where I put the receiver at and then mount the scope mount loosely on top and check it. The front need to be higher.

 

spec.4

[Guest SteveW]

Shims are largely needed for elevation adjustment, correct? Couldn't you simply place the bases on both rings and put a straight edge across them to see any elevation differences (at least for two pc bases)?

[z1r]

Stevew,

 

 

The shims aren't for elevation adjustment, rather they are to bring the bases to the same height so they reside in the same plane. The scope is for elevation adjustment.

 

Measuring will tell you exactly how much correction is needed. Levels, alignment bars and the like will simply tell you they are uneven but not by how much. Both kinds of tool have their place. But remember even .001" difference amounts to quite a bit downrange.

[Sailormilan2]

I did a Brno 98/22 last year, that was soo far off, that I had to use a small ring front base to get the rings to come close to lining up. Using the SR front base I will have to shim the rear a little. But no where near as much that I would have had to do to the front to bring it up if I used a standard LR front base.

[Guest Guest]

ZR1,

 

Sorry for the ambiguous terminology. I meant adjustment of the bases in the elevation plane to make them even, not elevation adjustment of the scope point of aim.

 

Point taken re: measuring vs level/straight edge approach.

 

Thanks,

Steve

[BobVZ]

On Mausers with ground receiver rings(seems like most nowadays) I have successfully used steel-filled epoxy to mold custom shims. I first mount the rear base and use a caliper (with the bottom jaw against the flat on the receiver bottom and the upper jaw on the flat of the scope base top) to check for level. You need to do this for both axes. Record the measurement for use in leveling the front base.

 

If its not level, shim with small rings of electricians tape punched out with hole punches. Place these on the bottom of the base around the screw holes. Once satisfied, coat the receiver, screws, screw holes and base screwholes w/release agent (wax). Butter the base with epoxy and screw on. Check for level again and let it set up. While the epoxy is still soft and pliable, take the edge of a sharpened credit card and cut off the squeeze-out from around the edges of the base. Its alot easier to do this now than later for obvious reasons.

 

Next, mount the front base and level it using the previous technique, but don't use epoxy yet. Once its level using the tape shims, compare the measurement you recorded earlier. It should be less since the receiver has been ground. Determine how many tape shims you need to bring it up level. Shoot for a level a few thousandths higher than the rear. Apply the shims. Finally, butter the front base and screw on barely snug. Using your calipers to check for level, crank down the screws till you hit that magic measurement. Flip the action upsidedown and place tops of bases on a flat surface. If everything is level, it should be perfectly flat with no rocking. Trim the excess as before.

 

After it is set, paint the edge of the epoxy with black paint to hide it and your done!

I like this method because it compensates for irregularities in the metal and assures a perfect fit.