Breech block extractor problem

[Dick Herman]

As you know, when a cartridge is in place the extractor pivots about the small retainer pin. The extractor retains the cartridge and projects above the breech block. The extractor moves vertically toward the breech block internal flanges for retention and alignment. The ejector pushes the cartridge and the extractor vertically upward. If there is forceful contact made with the small breech block internal flanges a cantilever load is applied. The vertically applied load causes a bending moment reaction to roll the internal flanges into the damage displayed on the photo.
IMHO

[Vic103]

The way you describe it makes total sense. Do you think the blow back has to much force causing this to happen? Because I believe I have good clearance on everything. Which would point to a worn main spring.

It's almost like using +P ammo, but I am not. I am shooting standard ammo.

[Dick Herman]

I have observed that the cartridge retainer finger section of the extractor should be completely clear of the breech block end cartridge counter bore when the cartridge is released. At that point there should be additional clearance before the extractor engages the small inner flanges of the breech block.

However, if the clearance of the extractor to breech block is insufficient or the ejector is too long, either situation might be forcing the extractor vertically into the inner breech block restraint flanges.

I suppose that if the loads are too hot the increased recoil could contribute to this damage. You did state that the cartridges were standard Federal 9mm Luger ammo. Is that a hot load?

We have more in common than Lugers, I served my Apprenticeship as a Tool Maker before going back to college to become a Mechanical Engineer.

[DonVoigt]

Vic,
replace the breech block before you decide the barrel is bad or cut too deep.
The block is the other part of the headspace equation, and a longer block will reduce the head space..

The Guages I measured are the go, and no go guages. There is a third-the "field" guage which is longer(I have not been able to find out how long) and is the one used to determine when repair is needed.

When you described measuring your head space, you did not have .776 as you "felt" resistance, but then kept pushing, so your head space IS below the max.

I would try again with a steel guage and do not use any force, of course the striker and it's spring must be removed for the test.

Even if it were slightly above the max, I do not think this is the problem or even part of the problem you see.

And don't forget, military specs and European specs are quite likely different than SAAMI specs.

Folks tend to worry about head space more than necessary, even to the point of obsession; within reason, head space only affects accuracy and the surety of ignition.

One of my favorite pictures is one of a short rifle cartridge fired in a long chamber, head space of about 1/4" and the only noticable
result of the firing was the odd brass that was ejected! This was caused by a re-chambered rifle that was not marked.

Has little to do with Lugers, but a lot to say about head space.

[Vic103]

Well... I got my order from Numerichs.

The breechblock was nice, hardly any fitting. Got a couple extractor springs, and a mainspring.

The mainspring can't be right, there is no way that spring would fit into my shooter. The wire diameter is.055, it has 22 coils, but it's like 4.200 long?!?

What the heck?:


Breechblock looks and works good (by hand):







I did order the mainspring set from Wolff, and I am still waiting on those. Oh yeah, my mainspring seem very stiff. The wire measured .055 diameter, it had 21 coils (looks like someone cut or ground one end of it. I forget the length it measured, but it was close to what the chart said that I saw in the sticky thread in this forum. To me my mainspring seems pretty good by the way the pistol feeds and ejects.

If these changes do not correct my problem, I think I will need to correct the headspace (mainly because I have run out of ideas) and that I know is not to spec. And the rest of the pistol seems to be in spec.

So I will be needing a new orginal barrel in good, to very good, to excellent condition, possibly barrel and receiver or whole upper assembly.

My funds are kinda limited right now, I've been pumping a lot of money into my AR's and AK's (wife is ready to flip out....he he)

I kinda hate to do this,but I have an orginal artillery Luger sight that I could barter with. If my breechblock problem dosen't get corrected and I decide I must change out barrels to correct headspace problem

Here are some pics of the artillery rear sight:

[G.T.]

When you decide what you'd like to do, drop me a note at gctomeks@msn.com I'm always doing crazy stuff like trading work for parts and whatever?......... I can re-barrel and headspace your receiver assembly correctly without too much trouble?....Best to you, til...lat'r....GT....

[G.T.]

BTW, if you want the best, look for a Mauser or Steyr WW2 armorers replacement barrel... it will probably index perfectly and headspace correctly as well... next would be any "GERMANY" barrel, followed by any "MADE IN GERMANY" barrel, after that, it is a crap shoot!.... I do have some nice take off barrels, but they are not new?...best to you, til...lat'r....GT.....

[Vic103]

Hi G.T.
Are you saying that my existing barrel could be corrected? I really like.(it is very well made, looks and matches the pistol's look (blueing wise) and bore is brand new!...just what sombody that wants a shooter needs.

How would you do it? I figure my headspace is about .020 too deep. I would have to spin the barrel one turn which amounts to about .040 or .050 thou. And that is about the thickness of my barrel flange, so round flat area would be gone it would become a sharp edge instead of a flat. Unless you have some trick up your sleeve.

[G.T.]

And I think that the barrel could be cut / set back one full turn, and at the same time cut (as large a radius as possible?) slightly forward as well? And then a spacer cut and pressed on to replicate the shoulder and flange area, and install and profiled same as the original concave radius and flange? It would be like a two part barrel?.... all it has to do is re-index correctly and tightly, and also have the extractor and feed ramp recut, and be re-chambered to close on the "GO"... I could accomplish that? It wouldn't be perfect, but I bet it would work?.... Anyway, some better than .020" too deep on the breech end??..... Best to you, til...lat'r....GT .....

[G.T.]

Hi Rick, My father was an old time gun shop owner thru the 50's and 60's... I was always anal about headspace, and he always said it's not a big deal???? We never resolved our differences on this matter? .. But, my opinion was, it never hurts to be within spec?.... Miss ya dad!......... best to all, til...lat'r....GT......

[DonVoigt]

Rick,
Your analysis of the possible reason for the upset breech block in the OP's pistol is logical and may be the cause for the upset material, along with a "soft" block to start with.

As I have said about this one, several times, he needs a new breech block. This may correct his long head space too. If it does, everyone is happy.

The OP did NOT check his head space correctly as described, and his pistol is not currently out of
specification, it may in fact be several thousandts below max. He used a Brass gage(deformable) and used pressure to close the toggle!
See his post #9 for how he checked head space.

Unfortunately in mechanical devices, min/max specs can add up the wrong way and 0.020 or more gap space or what ever are frequently present.
Given the condition of the bolt, it is tough to accept that just a few rounds did this, maybe a few +P rounds or hundreds of normal rounds; or a breech block that for whatever reason finally failed?

No one is advocating firing the wrong ammo in a wrong chamber, the point of that post is that when it happened, nothing "bad" happened, except to the brass. The chamber Should have been marked when converted, but was not.

Heads space is not a "mere token", it has it's place, but it is way over-emphasized by many, including some who work on these things. Using SAAMI gages to pass or fail military chambers is easy to do, but not correct in many cases.

Vic, needs to check his new parts combination with a steel gage and no excess pressure to close the toggle
see what he has now.

JMHO.

[DonVoigt]

"Nothing happened bad in the rifle deal, got that. Lots to say about the relative strength of the action and its gas handling characteristics. Might not always be that way, so why even approach the issue on trial and error; a basic, simple chamber cast might have prevented such, but in hindsight.................... probably not."

Just to put the rifle example to bed:
The rifle in question was a stock appearing T 38 Arisaka, with no indication that any modifications had been done. The round fired was a 6.5x 50mm Japanese, in what turned out later to be a 6.5 x 57 mm chamber.

The re-chamber to 6.5x 57 or as sometimes called 6.5 x Roberts was not marked, but should have been- and is now.

You were not "out of place" making suggestions, since we see the issue differently it is good
that you say what you think.

As to calling into question the way the OP did his test, he said himself that he used pressure to close the toggle, that it would not close without but stopped at resistance. Closing with pressure and the subsequent leverage effect , in my book, negates the accurate assessment of the measurement. So it took no "gumption" on my part to say it was not done correctly- he said so himself when he described his actions.

Like Forrest Gump said, "that's all I have to say about that".

[LugerMan.com]

After the OP, send me a link to this post.
I want to add my 2 cents.

One aspect of extractor movement is overlooked in everyone's response.

Any combination of case - extractor- breach block connection, will damage the case first, if the case is brass. Examine the cases if possible.

To damage the breach block in such a way by extractor movement , it has to do so by interacting with a metal.

The only metal extractor interacts with , other then breach block is barrel and slide.

I have seen this happen in cases of a barrel extractor clearance hole has been cut short or with a wrong angle,
or barrel twisted out of alignment just to the point where extractor slams in to it.

In any case extractor must found an obstruction on it's way, that has forced it up, without anywhere to go it pulled the breach block weakest point out.

At this point, i recommend, changing the barrel or cutting it back a turn with cutting all back geometry deeper for clearance as part of the rework.

Change the breach block and examining the extractor interaction with all parts , without firing the gun.

and possibly changing it as well, as it must have internal stress from such a damage.

I can do the rework if needed, and i have all the parts in stock.

Hope this helps

[LugerMan.com]

Originally Posted by G.T.

And I think that the barrel could be cut / set back one full turn, and at the same time cut (as large a radius as possible?) slightly forward as well? And then a spacer cut and pressed on to replicate the shoulder and flange area, and install and profiled same as the original concave radius and flange? It would be like a two part barrel?.... all it has to do is re-index correctly and tightly, and also have the extractor and feed ramp recut, and be re-chambered to close on the "GO"... I could accomplish that? It wouldn't be perfect, but I bet it would work?.... Anyway, some better than .020" too deep on the breech end??..... Best to you, til...lat'r....GT .....

I have spacers if needed, not a bad idea.
As long as a chamber not to long already.