Home Forums Hunting & Shooting Gunsmithing M1909 Argentine Mauser - Lug Set-Back (Again)

Gentlemen:

I posted this question on the Gunwriter's forum, but this is a better place. I've followed a number of threads about lug set-back on the 'Fire, AR, and a few others, and there really doesn't seem to be a lot of consensus: some have experienced it, some haven't, and some just heat-treat an action from the get-go in order to avoid it. But what I haven't seen an answer to is this:

If there is set-back, after firing a round is the bolt handle stuck or hard to lift, much like it would be if a load is too hot? Or is it only caught when measuring headspace from a fired round? I hate to be a pest about this, but I have a M1909 that often has a sticky bolt even with loads that I know are loaded to lower pressures and I'm wondering why. After reading some of these threads, I'm beginning to suspect that set-back might be the issue, although also from what I understand about the only way to tell for sure is to pull the barrel and examine the action face.

Thanks

Lug set-back involves excess pressures hammering the bolt back into the recesses which creates a concavity in the mating surfaces of the action. Generally there is a small bump behind the bolt lug due to the upset of metal.

The brass in the chamber has been fireformed in the chamber and therefore is a little bit bigger than when inserted (yes there is some spring-back in the brass, but it is still bigger) and the combination of the little bump behind the concavity and the bigger brass makes the bolt difficult to lift. It will also be a little tight when closing on that fired brass.

On Mausers small incipient cracks can often be seen radiating forward from the rear back corners of the bolt lug after set-back has occurred.

Thanks. I appreciate that. I can't see anything on the lugs: no bumps, no cracks. I don't get it. I'm going to fire some factory 140-grain Core-Lokts and see what happens. I know the 175-grain RN loads I shot through it are ambling along at about 2300 fps using Ramshot Hunter - nothing even marginally hot - but the bolt wants to stick. From what I understand, M1909s are a little harder to cock than M70s or commercial M98s - and this is true of another M1909 I have that was built with a hardened and trued action - but this is significant. I'll see what the factory rounds do. So far it's a mystery.

Thanks again.

The cracks would be on the bolt body beside the trailing edge of the lug and may not show. A simple mag particle peek will see the crack before the eye can.

You are not likely to SEE anything, even if you have set-back. The details you describe say your rifle has lug set-back.

I'not seen any cracking of the bolts on mausers but I have seen numerous cases of setback of the lugs in the receiver. Most often, this occurred in actions which were loaded real hot and/ or had been opened up for a magnum cartridge. The upper locking lug seat ended up with a ridge corresponding to the ejector slot in the left lug. I suppose this could be corrected by machining and re-heat-treating but I would not bother. GD

I have read a bit on the heat treating of the action on the 1909, basically some receivers are "soft" resulting in lug set back often at lower pressures. They can be tested , Rockwell harness etc as well as be re-heat treated to a harder standard.

A sticky bolt lift can be caused by many things. One of the best ways to verify setback is to pull the barrel and inspect the lug seats.

Mausers are tricky to diagnose due to their split upper lug. When the lug seats set back, a ridge is left due to the ejector slot cut through the upper bolt lug. This can lead to a false "good" reading if you try to use a headspace gauge. Because, as you rotate the bolt into battery, the bolt lug contacts the ridge and is forced forward into the gauge. The gauge being hardened steel, doesn't compress and will read like the headspace is fine. However, if the bolt would be allowed to go into full battery, then the excess headspace would be apparent.

In all the Mausers I worked on that had setback, not one had the bolt lugs set back or cracked. The setback was confined to the receiver's lug seats. The only Mauser bolt I saw with a cracked lug was an FN commercial. This due to the fact that the entire bolt was heat treated again after the swept bolt handle was welded on. Early commercial bolts were repurposed military bolts that had the new handle stick welded on. Then the bolt was re-heat treated. This of course resulted in a bolt that was too hard.

Mike--just checking.

You have tried different brands of brass?

Define sticky bolt? Is it simply hard to cock? Hard to lift the bolt only after firing? I take it this is chambered in 7x57? New bolt handle?

Thanks for all the comments.

Yes, 7x57, and yes, two different brands of brass.

I picked up this rifle as a foul weather rifle since it was in a B&C stock. I fired a little over half a box of Prvi 158-grain factory rounds and noticed then that the bolt was a little hard to lift after firing. I needed the bolt handle lowered a bit to clear the ocular, so had a new handle installed. I took it back to the range and fired a fouling shot using a 154-grain Interlock in a Hornady case. I almost couldn't get the bolt open even though the round is loaded moderately. I then fired a few more low velocity loads (175-gr @ 2300) loaded in Prvi brass, and even though the bolt wasn't nearly as sticky as with the Hornady load, it was still hard to open, about the same as the first day I shot it. As I mentioned before, from what I understand 1909s are a little stiffer than a commercial Mauser on cocking - borne out by how easy my Zastava M98 is to cock, not to mention my M70s - but this one is even harder to cock after firing.

I guess the only way to really know is, as you mention, to pull the barrel and check.

Thanks again.

Sounds to me like when you had the handle installed, they softened the cocking cam on the bolt. Pretty common.. Worth inspecting. If that doesn't do the trick, then pulling the barrel may indeed help determine what's up.

The fellow who did it is a pretty well-known custom gunsmith who specializes in Mausers, but it's certainly possible. I just need to think about whether or not I want to put any more cash into it as it currently sits. Of course, unless the action is ruined it could always become the basis for a custom or semi-custom build.

In any event, I certainly appreciate y'all's comments and the sharing of your expertise.

If the bolt lift is difficult after firing but not as difficult when empty, The lugs have probablyset back. The way to know for sure is to pull the barrel and have a look. GD

Definitely would listen to z1r & greydog...you have probably done this but just in case. The unusual seems to come with the exclusive crap I buy used.

chamber smooth & round?
measured the throat for seating?

Oh, I'm definitely paying attention. You can count on that!

Yes, the chamber is fine. Actually, and oddly enough, I have two other rifles that will chamber a fired round from this 1909. I have not, though, measured the throat for seating.

Did not intend to imply the bolt lugs actually get set back much, but rather they crack. I can find several bolts here that look like your picture just before the lug calves off. I can also dig out bolts that show tiny incipient cracking either through the lug or in the bolt body.

I do appreciate the commercial mauser information as several have been FNs.

Lets examine what happens when you have lug setback.

I think what you get is excess headspace.

I had a good friend who was a gunsmith (now deceased) who had lug setback on a military FN action. The caliber was 25.06. He had a tendency to load his ammo on the hot side of things. the lugs had rather severe setback if I remember correctly. And what he did was remove the barrel and then did what was necessary to reheadspace it. It worked fine thereafter.

Wow! That was superficial.

Headspace is not the biggest worry. It may remain within SAAMI specs with a serious issue extant. After shooting a round the bolt lift is difficult because the case has grown to fill the space and the "ridge" described by z1r (back side of the concavity as I described it) cause serious difficulty in lifting the bolt. Excess headspace is not an "if then, therfore" situation at all.

I appreciate everyone's comments. One more question (or maybe a compound question) and I'll let it go.

Ignoring cost/benefit entirely, assuming we're talking about lug set-back, can this issue be fixed? If so, who would do it and any ballpark as to cost?

Thanks

Two steps:
Determine if the action is hardened. Since cost:benefit is not in the question, have it rehardened if needed.

Have the barrel receiver lugs reground to clean up the divot/ridge and have the barrel set back a thread or two and remembered.

I have not had one done in a long time, but it used to be cheap.

To determine if lug setback exists, you need to perform a test on the action. With the bolt stripped and inserted in the action and closed, fasten a dial indicator to the action and the indicator pointer touching the back of the bolt. With a free hand, try to move the bolt fore and aft in the action and look for movement of the indicator needle, Do this with the go gauge inserted. Next, with the bolt partially opened (hopefully over any unaltered action lug surface) and notice if there is any movement or note the difference in the two indicator readings. What this will do is show if there is a step in the action lug surface. Confusing? Sorry

Again, thanks for the replies.

Jim: Reparable? Any ballpark as to the cost? Just a ballpark.

Repairable? Yes.

Cost, whatever the smith's hourly rate is for the time it takes them to machine the seats/lugs, plus the expense of heat treating. Then of course, the receiver at least will need to be blued. The other consideration is that the headspace with the original barrel may or may not be "good" afterward. If excess, then you are looking at setting the barrel back or some other means of re-establishing proper headspace. To complicate things, often, the "pocket" where the lugs back will pop back out during the heat treatment process. So, there are two schools (at least) on how to resolve: 1) Machine the seats and lugs if required, then heat treat. 2) Heat treat, then machine and or lap in.

option 2 is usually only viable if the setback is small. Tom Burgess liked this method when applicable.

This receiver had a goodly amount of setback when I acquired it. It needed a new barrel as well. The seats were machined lugs mated, and then sent off for carburizing. Rebarreled to 9,3x62 upon its return and restocked.

Repairable is good to know. Let me ask the estimated cost a different way since hourly rates vary: how many maximum hours are we talking, worst case scenario?

I am sure that others may have a different view.
Mausers are wonderful. I like them a lot. But fixing them is not always economic.
I have purchased nice hunting rifles, Remingtons, Savages, Winchesters, Rugers, for much less than it will cost to remedy your situation correctly.
Remove barrel, inspect seats for set back, set up in lathe, correct set back, reheat treat, reset up in lathe, lap lugs, set up barrel in lathe, correct headspace, re blue action and barrel, install barrel, these all take time. If youre doing it yourself, not such a big deal. Paying for a gunsmith to do it...can be really daunting.
If it were me, I would just move on, even though I really like Mausers.
Find a nice factory rifle and just hunt it.
I know this is probably not what you want to hear, but it will be much cheaper in the long run. Sorry, but that is my honest opinion.
re

Since the OP stated "Ignoring cost/benefit entirely, assuming we're talking about lug set-back, can this issue be fixed? If so, who would do it and any ballpark as to cost?" I attempted to answer accordingly.

Often, there are intangible benefits that shape our decisions, not just a strict cost/benefit analysis. There's a benefit to some in hunting with a certain rifle, or a type of rifle, that can't be overcome by cost savings alone.

But, on the whole, you are correct, it is probably less expensive to find a cheap rifle that to fix said problem.

I apologize, I did not read that part, or did not acknowledge it.
Yes, the work can be done.
It will be expensive. Quite a bit involved.
Sentiment is something I did not consider.
re

No apologies needed.

I've resurrected more than a few rifles that meant a lot more to the owner than did the expense of bringing them back to life. Some folks are much less attached to inanimate objects then others.

Thanks again for all the comments.

There's no sentiment in this rifle at all. I picked it up a while back to use when the afternoon rains make our hunting lease look more like Cameroon than Florida. My mistake was not running it through a full regimen of load development before spending money on it to have the bolt handle adjusted to better clear the ocular, as well as having a new safety installed. The entire rifle had been reworked long before I got it, so I don't lay any of the current issues at the feet of the fellow who did the work for me. Too bad it turned out as it did, really, as it puts five shots into less than 1.25 inches with the traditional 175-grain hunting load, and that's before tweaking the recipe.

So I guess my options are these: keep it in the safe for no apparent reason, or at some point spend the extra money on it to bring it back to life. Whether it's me or someone else, if it is ever going to be used someone will have to spend something on it. I'm just trying to get an idea of how much time might be involved. Five hours? Ten? More?

Thanks again.

If it was mine I would probably have it repaired. I would send the bolt to Dan Armstrong to do a new bolt handle.
One of Dan's bolt jobs

Another

Another

Dan is very good, fast, and inexpensive. http://accu-tig.com/

Length of time involved really depends on who does the work and how they do it.

Probably best to first figure out exactly what is wrong, then you'll have a better idea of what work needs to be done. Much easier to get an idea of cost once you know what all needs doing.

Good points. I appreciate it.

That is a nice looking rifle, Butch. From the sounds of it it's going to take more than just a bolt handle to get things back in order. I'm gonna chew on it. Who knows - maybe I'll splurge for another sheep/goat rifle...which a pig hunter in Florida needs like an Eskimo needs a bikini.

Kinda like my 458 Lott for my Texas squirrels.