Many military surplus rifles that were originally case hardened later had their crests ground or polished off. This is most often evident on Mausers. It seems intuitive to me that the receiver ring strength would be somewhat compromised if this "skin" is ground off the top of the front ring. The receiver is somewhat like a sausage that's had one side of the casing removed. Does anyone have any empirical evidence to share that can confirm or refute weakness from case skin removal?

Thanks, Bob

For the most part the case head remains the weak spot on most bolt guns.

Nearly all small ring 1891 Mausers have the crest ground off of the receivers. I once blew 2 primers in one without any effect on the rifle.

Yes the grinding destroys the originality of the action, removes a handsome crest in some cases but does not seem to reduce the strength significantly.

From my experience 98 Mauser receivers are not cased all over, I've never had any trouble drilling or filing the outside of one.
I believe the case hardening was applied selectively to the wear surfaces and areas subjected to shock load, mostly on the inside.
I took a file to a 1937 Portugese contract recently with no problem and they were supposed to be hardened using the cyanide bath process. Kind of indicates that stop off was used even on the late ones.
Besides, a carburised exterior would have been murder on their expensive proof stamps don't you think?
Try this, grab a bolt handle and run a file over the knob, it will cut easily. Now try the file up near the root, different story all together.
Not saying this is the case on every Mauser ever made, just the ones I've worked on, 1908's, 1909's, VZ's, GEW's, Steyr's, FN's etc.

Just the surface few thousandths is ground off; has nothing to do with receiver strength. Case hardened receivers were hard on proof stamps, which is why you see WaffenAmpt eagles that are devoid of all detail on late war 98ks. I think they went through a lot of stamps during WW2. Metal, yes, 1908s, 1909s, are very soft. VZs, soft, FNs, soft. Gews; vary. 98ks; hard; late ones are very hard.

quote:

Originally posted by dpcd:
VZs, soft,

I believe you are mistaken. One of the attributes that makes the VZ24 a desirable action is the fact that their heat-treatment seems to have been consistently well done.

I wondered about it, but then I recalled that interrupted-thread takedown models are apparently strong enough, as are these: http://www.gunbroker.com/Aucti....aspx?Item=420026001

Thanks for the replies. I am aware that there were differences in degree of case between the interior and exterior, but the exterior received some case. I have several Mauser rifles that have been D&T'd and all have hard skin around the holes. Literature references state that receivers left in-the-white were cased for rust resistance. Like you, I have never seen conclusive evidence that scrubbing affected safety. I did think that the roll stamping was done before case hardening and not after for obvious reasons, just as primary machining is done prior.

jb, I have done many vz24s; none of them are cased glass hard, not as soft as a dwm but not cased hard; they do seem very tough. I consider them among the best and strongest 98s. By soft, I mean they can be filed easily. DWMS are usually very soft. It is all relative.
BTW, the last MW marked 98 I worked on, last month, was harder than the hubs of hell on all surfaces, in and out. It was an intermediate action with the crest already ground off.

I just checked 4 vz24s; all filed easily on all surfaces. You guys realize that none of this means a damn thing; Mausers are made from low carbon steel, selectively case hardened in the areas where it matter. You can file any modern steel alloy action very easily too. Surface hardness is no indication of strength.

Don't get me wrong, when I say they are easy to file I'm not saying they are soft.

So are we then saying that the chamber-barrel tenon is not strong enough to contain the cartridge upon firing by itself? That the receiver reinforces it?

Absolutely NOT; the receiver ring contributes nothing to the hoop strength of the barrel. Only in cases where the case head blows and the receiver has to contain lots of escaping gas, and always, a certain amount of backthrust from the case head, does the receiver do it's work. You would not want your barrel expanding at every shot and having the receiver ring take any pressure.
Metal; I guess I was saying that if I can file them, then they are "relatively" soft but that doesn't mean weak; I was just trying to relay some gross comparisons of different receivers in a way we all can understand and duplicate.

So then it follows that grinding the front ring, as it is done by custom makers does not affect the strength of an action?

Since they only grind a few thousandths off; no. Hell, Mauser used to cut huge dovetails in the rings and were not concerned about it.

Of all the responses here, I suspect DPCD's contain a lot of accurate info.

I personally can add little to his posts, except to say I have seen HEAPS of custom rifles built on military Mauser actions that had a lot of pitting on them until the surfaces were ground or filed down to eliminate the pits.

Not a one of those rifles ever failed in actual use so far as I know. So maybe it weakens them and maybe it doesn't. But they seem to have more than enough strength to still perform their duties. So I'd judge any increased weakness insignificant to their performance.

I actually have one of those Mauser receivers with the huge dovetails milled into the top of the ring. I'm doing a rebuild with it, and I was wondering just what sort of scope mount was used (I'm assuming that's what it was done for),I don't seem to come across any bases with the dovetailing that would fit this modification. Can anyone enlighten me? Sorry, I didn't mean to get off topic here.

The dovetail is for a claw mount base. The correct method is to solder a dovetail base on the front ring and insert the claw mount. However, this wasn't always done, and the ring itself was dovetailed.

As to the OP's topic. The barrel takes the brunt of the cartridge force, and the threads take the forward thrust. The outer part of the reciever shouldn't see any force unless a catastrophic event happens. This have all been said already, but I'll throw in my 2 cents that are not quite worth that amount.

Jeremy

On many bespoke ("custom") Holland and Holland rifles the crest, if any, is not ground off but gone over with a fine stippling punch to "remove" it that way.

In the same way an unwanted tattoo is "removed" not by peeling off the outer layer of skin but by going over it with another tattoo.

Grinding, as such, would be too imprecise in leaving a uniform sized ring for pre-made off the shelf front bases.

quote:

Originally posted by enfieldspares:
On many bespoke ("custom") Holland and Holland rifles the crest, if any, is not ground off but gone over with a fine stippling punch to "remove" it that way.

In the same way an unwanted tattoo is "removed" not by peeling off the outer layer of skin but by going over it with another tattoo.

Grinding, as such, would be too imprecise in leaving a uniform sized ring for pre-made off the shelf front bases.

Much of the grinding, that is spoken about, was done on a fixture, with an expanding mandrel thru the bolt bore, on a surface grinder. Some was just done by hand to remove the crest.

It was popular at one time to grind the sides of a large ring Mauser down to small ring dimensions and create an oval appearance. It made a slimmer custom rifle. I think Jim Wisner did some back in the day and posted about it a few years back. That is quite a bit more removal than removing a crest. To my knowledge no guns treated like that (correctly) are known to have failed at the front ring.

I guess my concern is in the upper web between the lug seat and the breech face. It is more related to stretch and failure. I have photos of a couple of Mauser actions that failed in that area and the right lug raceway. It is pretty thin to begin with and further grinding seems to add to the potential for failure.

quote:

Originally posted by farbedo:
The dovetail is for a claw mount base. The correct method is to solder a dovetail base on the front ring and insert the claw mount. However, this wasn't always done, and the ring itself was dovetailed.

As to the OP's topic. The barrel takes the brunt of the cartridge force, and the threads take the forward thrust. The outer part of the reciever shouldn't see any force unless a catastrophic event happens. This have all been said already, but I'll throw in my 2 cents that are not quite worth that amount.

Jeremy

My opinion is that once you reach the influx of gas that causes those failures, a few thousandths more or less of steel won't make any difference. If it bothers you, then don't use one that has been ground any. But those are virtually all I use; ones that have had crests ground off. Not talking about grinding a large ring, large thread, down to a small ring.

quote:

Originally posted by Bobster:
I guess my concern is in the upper web between the lug seat and the breech face. It is more related to stretch and failure. I have photos of a couple of Mauser actions that failed in that area and the right lug raceway. It is pretty thin to begin with and further grinding seems to add to the potential for failure.

I'm having a hard time with that one. It seems that actions such as the Enfield are MUCH thinner in that area.

I have always thought that LR M98s are thick(overly thick) in the upper web area.

Small ring Mausers are quite thin over the right
bolt way and won't hold gas. When we copied the
93 Mauser to make the Springfield they left it
as a small ring but added material over the
right bolt way.

Interesting observation about the 1903. Hadn't thought of that, but quite obvious looking at that big lug of metal on the side of the action.

It is on the 1917 too; and when Remington built the Model 720, guess what they did? Ground it off.

It would be helpful if a metallurgist, engineer, or experimenter would comment on the effect of dovetailing a receiver as to the extent of the weakening of the receiver. Sometimes what appears to be true can turn out to be false.