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Dry firing the FG42

pitfighter

Senior Member
I'll preface the thread by stating:
Every book written on the FG42 including all amendments to the 1944 manual state that no model of the FG42 should ever be dry fired. Not once, not by accident, not when assembling, testing or clearing.

I am presuming, as no further information is available, that it has something to do with the weight and travel of the piston that hits the firing pin itself putting unnecessary pressure on the small discs that hold the firing pin in place.

That being the case, the old wartime drill purpose rounds, the ones with the indents down the sides and missing primer would not help, as there is zero resistance to the firing pin, and the damage would still occur.
For this "supposed" reason I am looking at modern snap-caps with a spring assisted "primer" area, that gives resistance to the firing pin.

I do want to cycle this some without live ammo in it, and should it dry fire, I don't want to damage it. Of course it would not be dry firing often, and that is not the intention, just once or twice.

Does anyone have more information on this matter?
 
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Based on my limited knowledge, (and observing the effects of accidentally dry firing my smg42), it appears to me as though the pin in tapered to fit through the bolt face. If it does not strike a primer or something providing resistance, the backside of the bolt face will dig into the pin along that taper.

Assuming a real FG42 is like the Smg42, I did this once and have a small silver ring where it dug into the tapered pin. Has had no negative effect yet. But repeated events could mess it up.
 
dry fire?

OK, the manual says what it says and the SMG FP got a visible mark from dry firing. Would it not make sense for the designers of whatever firearm to know that no matter what, dry firing might happen often during the life of the weapon and take that into account in the design?
Some yes, some no I guess. Doing it often is probably not the best idea in the world regardless but once in a while "should" be ok I'd think.
Maybe not some guns?
Pete
 
I have not dry fire d my FG42E, but a friend of me did it a few times with my rifle before I cud stop him. Nothing happened, but I imagine it will be hard on the op rod. Same when you pull it out of the rifle, you must be carefull with the bolt and rod
 
I have not dry fire d my FG42E, but a friend of me did it a few times with my rifle before I cud stop him. Nothing happened, but I imagine it will be hard on the op rod. Same when you pull it out of the rifle, you must be carefull with the bolt and rod

I think where the manual is concerned it's a military thing -
If you say it's OK, but not too much, soldiers (Paratroopers) will pay no attention, so you say it is forbidden. That might have some effect, lol.
 
Good point Pit.. Met a Tiger driver that fled when his Schwere Panzer fell through a bridge. He was told any damage blamed on him could result in a firing squad!

I wonder if Rick will chime in at some point? I'm trying to find the video he included with mine and see if dry fire is talked about. I should take a closer look at mine. Ive always worked it with snap caps but that hasn't stopped a few FJRs from pulling the trigger before I could stop them.
 
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The FG-42 was more or less disposable, right? They were expected to have a low round count and then to be replaced. That it breaks after stuff seems logical in that light, it wasn't made to last.
 
The FG-42 was more or less disposable, right? They were expected to have a low round count and then to be replaced. That it breaks after stuff seems logical in that light, it wasn't made to last.

You are generally speaking, correct, however, the FG42 series was exhaustively torture tested in a similar way to modern weapons (12,000 rounds endurance tests under all conditions), was expensive to produce and made by only two contractors (really only Krieghoff in any number), who were still observing extremely high (by comparison with other factories) standards right to the very last days of the war, the G was more easy to produce than the E, but still a complicated and very laboriously manufactured item.
Where you are correct in that it wasn't designed to be a family heirloom, it certainly wasn't designed with the view to simplicity that the STG44 was, (this was also why so few were made.)

*In the rather more brutal comparison trials it's performance against the STG44 was so close the results were assessed in the following manner.
1. The Heer Command believed the STG44 had performed better.
2. The Luftwaffe Command believed the FG42 had performed better.

Reading the manual more, there are several other places, where the language is similarly toned, "...it is expressly forbidden for the shooter to perform any further maintenance in the field..."

There is also a concise description in the firing section on how the movement of the gas piston carries the tip of the firing pin through the hole in the face of the bolt head to fire the chambered cartridge. It's a lot of inertia and metal to metal, and over travel is possible without a primer or snap cap to stop the firing pin moving forwards.

From the manual.
C. AFTER FIRING:
Remove magazine. Pull the bolt back and ensure that the chamber is clear, then pull the trigger and slowly let the bolt slide forward again.


Unfortunately we don't have the FA option with open bolt operation on the SMG semi, or my semi-only Krieghoff - so snap caps it is :)
 
I recall seeing photos of US testing of the guns and I recall parts breaking off of them during testing. Maybe the shell deflector? I'm convinced that no one has ever designed and mass produced an 8mm Mauser semi auto that doesn't disintegrate or break over prolonged use.
 
I recall seeing photos of US testing of the guns and I recall parts breaking off of them during testing. Maybe the shell deflector? I'm convinced that no one has ever designed and mass produced an 8mm Mauser semi auto that doesn't disintegrate or break over prolonged use.

Yes, the shell deflector came off on the US testing, and on the Heer trials report, there are other descriptions of breakages and malfunctions associated with round count.

We have a 8mm ZB26T which just keeps shooting, but it's hardly a light-weight semi-auto, the Hakim is also very reliable, but not full auto, but I know what you mean - a light-weight 8x57mm in semi-full auto was a hard task, especially in 1944.
 
Yes, the shell deflector came off on the US testing, and on the Heer trials report, there are other descriptions of breakages and malfunctions associated with round count.

We have a 8mm ZB26T which just keeps shooting, but it's hardly a light-weight semi-auto, the Hakim is also very reliable, but not full auto, but I know what you mean - a light-weight 8x57mm in semi-full auto was a hard task, especially in 1944.
Yes it is a hard task, but incredible fun and nice to shoot. My son fired mine in FA when he was 12
 
Hi All,
Since KDF asked.... First a question to Pit. What small disks holding the firing pin on? Pictures? On our rifle it is not a big deal to "dry fire" past the point of eventually inertia pulling the tip off the firing pin or causing it to separate in the middle where it fits into the carrier yoke. Has not ever happened yet but I am sure it will one day.

If I warned against it in the CD that comes with the rifle I need to revise it as the actual warning is about not letting the bolt slam home on empty with no magazine as the full recoil spring driven freight train of a bolt/carrier assy then gets stopped only by the sear.

The sear is made from really hard S7 TS but still it is a tough stop. When a mag is in the rifle - as when it runs empty - the follower does the stopping and when you remove the mag then yes, next in line is the sear. But the distance from the mag follower to the sear is a much shorter distance to accelerate the mass than full recoil plus is under much less spring tension at that point.

As to the damage being done because the firing pin is hammered by the carrier, that does not happen, at least in our rifle. The thing that stops forward motion when dry firing is the front of the carrier slot in the bolt. The ring mark on the firing pin is yes, from a light kiss of that to the inside front of the firing pin hole in the bolt. The tapered shape in that area of our firing pin is an effort to keep the inertia from doing the deed when owners just can't help themselves.

Snap caps are still the best if you just want to pull the trigger on nothing since things just can't be made good enough to never fail when used in all situations. Rivets with a thin backing failing on a case deflector wouldn't surprise many I think and is no real indication of anything else. It was a flimsy attachment maybe?

Rick
 
Yes, the shell deflector came off on the US testing, and on the Heer trials report, there are other descriptions of breakages and malfunctions associated with round count.

We have a 8mm ZB26T which just keeps shooting, but it's hardly a light-weight semi-auto, the Hakim is also very reliable, but not full auto, but I know what you mean - a light-weight 8x57mm in semi-full auto was a hard task, especially in 1944.

I'd add that perhaps we forget sometimes what conditions these rifles were assembled under. Poor raw materials and bombing and shelling. Oh and lets not forget sabotage. I'm amazed sometimes how well these 70 plus yr old beauties perform.
 
Hi Rick,


The discs' in question being machined onto the firing pin itself.
Borrowing Wilheim's pics as they show a comparison with your fine work.

P1120218_zps4a1edf97.jpg

Damage to those machined parts is what I believe was the issue with the original fg42 dry firing.

But more specifically, the original had two firing springs in full auto, the main recoil spring, which would send the bolt forward when firing in the open-bolt FA position, but also, the smaller semi-auto firing spring, which was attached to the firing pin, for use in semi-auto closed bolt position (BTW this is the redundant spring on the open bolt only M60) -

I think dry fire in the FA mode (using both springs) would mean excessive inertia against the firing pin machined "stop" plates/discs, and cause cracking.

In semi-auto, closed bolt, it is only that little firing pin spring that is whacking the primer, and not, causing a lot of inertia against the parts. Anyway, I posted to get opinions rather than give my own.

Only my total lay man's verdict - (I also thought Conner had a chance.)
 
Ah, I misunderstood what you wrote "small disks" as some sort of separate parts but see you just meant the rings machined on as part of the firing pin. And I agree that slamming home from the open bolt position is the worst I wonder if the forward travel is not finally stopped by the end of the slot in the bolt as on ours. Thats what limits firing pin protrusion and without it it would have to fall to the disks o the pin taper coming to rest against something. I have a bit of knowledge of our FG but about none on the original......
 
And even in semi auto both the firing pin spring and recoil spring are under tension and contribute to setting the cartridge off. Like you said, the open bolt FA setup doesn't need the extra force of the firing pin spring. I will say if you take it out in a rifle set up yo have it it will result in a faster opening of the action as the extra resistance to camming open the FP spring gives does slow things a bit, at least in our rifle.
 

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