I’ve summarized my work on blank adapting the SMG FG42 II in a document…
Click on the photo for the PDF…
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01 Feb 2012 / Weapons
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29 Jan 2012 / Weapons
I’ve done more feed testing with the Atlantic Wall long 8mm blanks. Results are still fairly bad with feed problems caused by the short length and square nose of the blank when compared to live 8mm ammunition. The FG42 will not function well until someone makes a full length blank.
From 15 rounds in one magazine I had 5 failures to feed. 33% failure rate.
The square nose and the short length of the 8mm blank combine to make it very difficult for the FG42 to feed the blank into the chamber. Any small misalignment will cause failure, the bullet nose must find the chamber opening, the large flat area is the bolt mating surface (remember this weapon has a rotating bolt).
Below is a simulation of a live 8mm round being fed. Photo 1, starting position…
Position after the bolt begins to push the cartridge forward… notice the longer pointed nose of the bullet has entered the chamber.
Here is the start position of the 8mm blank round.
Position after the bolt begins to push the blank cartridge forward… notice the flat nose of the bullet has struck the edge of the chamber.
The end result of the bolt slamming forward with the nose of the blank cartridge on the edge of the chamber…
Also remember my caveats in blank adapting.
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27 Jan 2012 / Reenacting, Weapons
I’ve created two versions of a blank adapter for the SMG Guns FG-42 II. I’ve made copies for my friends in II./FJR.
The first version is a simple screw on cap with a .105 orifice. Just like Rick at SMG Guns made. Simple but non adjustable for different blanks.
My second version (patent pending) has an adjustable orifice.
Non adjustable is $50, adjustable is $75, shipping included. Contact me at feldwebel@fallschirmjager.net to order one.
If you haven’t bee following this thread here’s what I’ve posted about what I’ve learned in experimenting on adapting the FG42 so far:
Also remember my caveats in blank adapting.
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23 Jan 2012 / Equipment, Reenacting
A got a couple of new photos of my FF33 field telephone crate from Will at Nord-Ost Fabricken-Werke. The heavy snows up North have slowed the a bit but they’ve got it into close to finish shape.
I can’t wait to get this crate. It will solve my problems in transporting these heavy, but relatively fragile bakelite telephones!
Another bit of good news, they’ve started on my K98 rifle crate!
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22 Jan 2012 / Weapons
I’ve done a bit more comparison work on ammunition; both live and blank in diagnosing my efforts to blank adapt my FG42.
First note that there are three what I call feed conditions. They are artifacts of the staggered row magazine used in the FG42. The first two conditions alternated between all rounds loaded in the magazine except for the last round. These rounds will be fed against the bottom or the top of the ramp depending upon which side of the magazine it is on. All of these rounds are stripped and move forward in the magazine, held by an decreasing length of the feed lips and strike the side of the bullet nose against either the top or bottom of the feed ramp and are guided into the chamber.
The other feed condition is the last round in the magazine which is always fed from the bottom side. The last round strikes its nose first on a ramp built into the magazine follower and then to the FG42′s ramp.
You can see this last round condition in this photo…
The critical items in stripping the round from the magazine and feeding it into the chamber is it’s angle and it’s length. I’ll explain more in a bit. First look at the relative lengths of the rounds when stacked in a magazine.
Three rounds in a magazine…
Bottom, last round condition round mostly hidden, just it’s nose peeking out; Atlantic Wall long 8mm blank (70.5mm length). Second, top side; Mitchell’s Mausers 8mm live round (77mm length). First, bottom side; K98 short 8mm blank, (63mm length).
The critical measurements is the blank case length, which also influences the length of ‘bullet’ when it strikes the ramp.
The Mitchell’s Mausers 8mm live round (77mm length) still has engagement of 21mm of magazine lip when it’s nose has just begun to deflect up the FG42s feed ramp. This keeps the cartridge from taking too much of a deflection angle as it feeds toward the chamber.
The Atlantic Wall long 8mm blank (70.5mm length) has engagement of only 13mm of magazine lip when it’s nose has begun to deflect up the FG42s feed ramp. When hand cycled this cartridge will work as the speed and force of the bolt will not deflect it at too much of an angle to prevent if from feeding into the chamber.
However during automatic cycling following firing the speed and force are too much for just 13mm of feed lip to prevent too much deflection. The usual result is a misfeed with the nose of the cartridge clipping the edge of the chamber.
The K98 short 8mm blank, (63mm length) has engagement of a tiny 7mm of magazine lip when it’s nose has begun to deflect up the FG42s feed ramp. When hand cycled this cartridge will deflect it at too much of an angle to prevent if from feeding into the chamber at all.
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20 Jan 2012 / Weapons
I’ve already blogged about my prototype blank adapter (here) made of T6061 aluminum for ease of machining with replaceable orifices. I don’t expect that to be the one I use for the long haul since the aluminum will eventually break down under the hammering of repeated blank firing. Its purpose was to allow me to find the right aperture to match the Atlantic Wall Blanks that I’m using.
I made a new one out of cold rolled steel, in my final chosen form… all that awaits now is the final drilling of the orifice. I may also tap and drill the end to use a standard hex plug where I could make a range of plugs with different orifices.
I’ve committed to make a few more of them for my friends in FJR/2. The hard part of making this little bugger is the internal threads. I could buy a tap, however large taps are expensive and I’ll only be making a few. The flip side is that cutting internal threads is a finicky operation and takes a lot of concentration to do right.
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19 Jan 2012 / Weapons
I’ve been posting what I’ve learned in experimenting on adapting the FG42 so far. In summary; the FG feeds every bit of live ammunition I’ve used so far, no misfeeds. Hand cycling works for the Atlantic Wall long blank, it will not work for a short K98 blank.
I’ve posted summaries of my experiments so far:
I’ve made an adapter, the base opening is .157 – that’s not enough to
cycle the action using Atlantic Wall’s long blank. I’ve made a reducer
insert and the orifice is .129 which cycles but the FG misfeeds the second
round.The key problem is due to the rotating bolt the chamber opening is flat
except for the chamber itself so cartridge alignment is critical.Here’s a couple of photos of the bore face and chamber…
You can make out the flat bore face and the pockets for the locking lugs to the sides of the bore face. As you can see it’s a pretty small target to get the cartridge into… and why the K98 blanks would smack their noses to the side of the changer and fail to feed.
The shorter cases don’t have as much feed lip engaged as the back of the bolt nears the chamber so the cartridge is at a greater angle. I think the key to making the whole thing work will be a full length blank. But as you can see from the brass the current case stretching is making the case walls pretty thin and making for a pretty mangled cartridge.
I’m going to experiment with larger openings to find the largest that will still effectively cycle the bolt. Unfortunately I’m out of blanks so I’ve called up Atlantic Wall and ordered several hundred more…
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16 Jan 2012 / Events
On January 18th Fallschirmjäger.net will go dark joining with many other websites in a protest against the SOPA and PIPA internet censorship bills pending in congress.
You can read more about the bills and the strike at Strike Against SOPA and you can help us petition both houses of congress to halt this wholesale giveaway of rights and granting Hollywood executives the power of censorship without limits. You can find out why these bills which are opposed by a majority of Americans are so wrong at Stop American Censorship.
Cory Doctorow summarizes the reasons to stop SOPA quite well at Boing-Boing.
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15 Jan 2012 / Communications Equipment, Equipment
Will from Nord-Ost Fabricken-Werke has sent me a few new photos of my FF33 crate under construction.
I like the joinery they do… just like the original crates that I have…
It is just like the original crates that I have…
Here it is clamped up with the glue setting…
And the lid of the box likewise…
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12 Jan 2012 / History
I recently added to my collection a verified signed photograph of General Kurt Student (12 May 1890 – 1 July 1978) the commander of the Fallschirmjäger!
Right now I’m having it suitably framed along with it’s certification papers, but you can bet it will be a part of my future displays…
