How 'bout a .22 Pedersen device?

S

Scope Scar

Inactive
Recently I saw a video of something pretty rare: a working, firing Pedersen device. It was footage from only a few years ago, too. I have a second-hand Pedersen anecdote, which I’ll post if people would like to read it, but right now I’ve got something else to say.

It’s time for a couple of you clever gobblers with a machine-shop in your back pocket to engineer a .22 long rifle semi-auto device to fit into a .223 bolt action rifle. Mind now, I said bolt action, not an AR15. A bolt-gunner is apt to be a saving sort when it comes to ammo, and I think that a .22 lr option would suit him just fine.

Here’s another “mind now”: This would have to be a 100% drop-in device; I’ll be damned if I’ll allow any bubba-work on my expensive CZ 527 or anything similar. Given the small cartridge, it ought to be possible to make such a device within the dimensions of the existing rifle bolt. Feed would be from the bottom; we’ll have no crazy-angled Pedersen mag sticking out in the air. I mentioned the CZ 527, because I think the removable mag would simplify the problem of fitting the device’s mag using, probably, an adaptor in the existing mag well. A proprietary ten-round .22 lr magazine might be included in the package, but if the device could also feed from a 30- or 50-round banana mag, then all is well.

That’s Model One. When it’s on the market and selling nicely, you can bring out Model Two, chambered for .22 WMR. Might take a little more engineering, but I’ll bet it would go down like ham at Sunday breakfast.
 
As you probably realize, such a device could not be universal or even for a group of rifles. There would have to be a different "device" for each make and model of rifle. For example, one device might be made to work with a short action Remington Model 700, but a very different one would be needed for a Model 700 Long Action, yet another for the Remington 798, another for a Winchester Model 70 long action, etc., etc.

The upshot is that (IMHO) there would not be sufficient demand for any single device model to make commercial manufacture practical.

And the device itself is not simple; the originals are very complex pieces of machinery. And changes were needed to the Model 1903 rifle to enable its use, resulting in the Model 1903 Mark I. That kind of thing was feasible only when a large number of identical devices were to be made and cost, essentially, was no object.

There are, or have been, other alternatives, including steel chamber adapters into which .22 LR cartridges can be inserted. They work OK, but there was never much of a demand and I am not sure any are still made. It seems that when push comes to pocketbook, most owners of center fire rifles who want to shoot .22 LR simply buy another rifle in that caliber.

Jim
 
It seems that when push comes to pocketbook, most owners of center fire rifles who want to shoot .22 LR simply buy another rifle in that caliber.
Click to expand...

I think the main reason for that is

#1) compared to centerfires, decent .22s are cheap.
#2) no centerfire has a bore sized correctly for the .22LR, so accuracy of adaptors is generally only fair.
#3) buying a separate .22 gives better accuracy, and removes the (potential) pain in the butt of using a chamber adapter or a conversion unit, which is having to remove and replace parts. A different rifle allows you to switch between them simply buy putting one down and picking the other up...

As to a Pedersen type device for a semi auto .22LR in a .223 bolt action?
It would be an interesting design challenge.

First, there is the challenge of building a blowback small enough to fit in the space available. As James K mentioned, it would have to be specific to each model of centerfire, so it could use the host rifle's trigger system, and it would have to lock into the host rifle securely. Not just for safety and convenience, but for accuracy.

.22 centerfire rifle bores are a little too large for best accuracy with .22LR bullets. (some would say "any accuracy"), so essentially your .22LR barrel is whatever you build into the device, which will end at the .223 chamber mouth.

So you get a couple inches of barrel for the LR, held in alignment with the host rifle sights, how? (what ever your design uses)

SO, in order to use the converted rifle, you will almost certainly have to re-zero the sights, possibly drastically. Possibly even more than the host rifle sights will allow for...

Accuracy will matter, not just in actual shooting, but in any potential demand for the device. No one is going to want it if only manages "minute of paper plate" at 25yds, isn't consistently repeatable, or if the different POI is outside the usual range of scope adjustments.

And THEN, there's the cost. MSRP of a new Ruger 10/22 carbine is still under $300. Good used ones go for half or 2/3 of that, and Marlin semis are much cheaper yet. So, your device would have to compete with that, cost wise, and be reasonably accurate, AND reliable, otherwise, (Other than the novelty factor) no sale. (reliability means not being a jam-o-matice, and here magazines make a BIG difference)

So, some moderately tough (but I think possibly do able) engineering challenges, and some rather tough business model challenges in order to be a viable commercial product.

The Pedersen device was made to give short range firepower (the concept of the day was "walking fire") so the infantryman was better armed closing on the enemy's trenches than the 5 shots in the standard rifle.

And while they apparently did work, mechanically, we NEVER used them, and only a handful of those made escaped being scrapped after the war.

As a hobbyist project, a .22lr Pedersen would be a neat project. As a commercial venture, You are aiming at a VERY SMALL market, and I think that unless they are essentially as good as, and as cheap as a used .22LR rifle, you will have a tough time selling them.

GOOD LUCK!!
 
Most modern bolt guns now have detachable magazines, so it seems to me that you could make a similar device that loaded from the bottom and ejected out the top or side.

Also, while I'm sorta with the other guys about buying a stand alone platform for .22lr. However, if you stayed with .30 caliber bullets, maybe a new cartridge that was subsonic, that would have some appeal.

Suppressors are much more common these days. Having the ability to transform a rifle from a long range platform to a semi auto, suppressed weapon seems pretty cool.

Still, would have to be platform specific, and cost less than a new gun would, but I bet there would be a small market for that.
 
I have thought about making a .32 ACP Pedersen device for my Mosin Nagant. There are a number of challenges, especially if you didn't want to modify the gun (Pedersen Devices usually require a cut to the receiver)
 
If the OP's CZ 527 is "expensive", just think how he would feel about the price of a device that fits into the action to allow the rifle to fire 22LR. Unless it were mass-produced, the cost would be significant. We generally think of 22LR rifles in general as "low cost", but here you are talking about a drop-in device a-la Cenier adapter or Pedersen adapter that will easily cost as much as or more than the rifle you are trying to avoid buying.

Accuracy of a 22LR fired through just about any centerfire barrel would be dismal. In general, people object to buying inaccurate, expensive firearms. I can only think of a few exceptions, and even those were relatively accurate and only moderately expensive (e.g. the Calico and the GyroJet pistols).

And lastly, the Pedersen device was a financial boondoggle and a failure in it's own day, and would be a NFA item today.
 
I have thought about making a .32 ACP Pedersen device for my Mosin Nagant. There are a number of challenges, especially if you didn't want to modify the gun (Pedersen Devices usually require a cut to the receiver)
Click to expand...

Go to your local library and research through some old Gun Digests from the 60s (can't remember exactly what year and I'm too lazy to look through my own).

There was an article with photos about some little known experimental Pedersen devices for both the 1917 Enfield and the Mosin Nagant. The 1917 should be obvious, but so many Mosin Nagants were never delivered because of the Russian Revolution, that some Ordnance Board members apparently felt it was justified to develop a device for them.

It's also not too well known that some AEF units sent to Russia in 1920 were equipped with those Mosin Nagants to simplify ammo supply.
 
And lastly, the Pedersen device was a financial boondoggle and a failure in it's own day, and would be a NFA item today.
Click to expand...

It's not an NFA item as far as I know. It only fires semi automatically. It's no more an NFA item than an M261 .22 unit for the AR15.
 
All the same....

Yes, a .22 lr sorta-Pedersen device would initially be platform-specific, and yes, it would have to start as a toolroom project for a stubborn innovator -- but it wouldn't be much more challenging to make it modular so as to fit the parent rifle receiver you happen to have. After all, we're not dealing with high pressures.

Okay accuracy can be achieved from a .223 bore with .22 lr if you use the right brand of ammo, or so I'm led to believe by my vast research on youtube.

As for a .30 cal device: Heck, just chamber it for 7.62 Tokarev. Something like this was proposed to the British army at the beginning of WW2, and one rather crude prototype even built, but it answered no real need and didn't get any farther.
 
Remember the M1903 Mark I had to have an ejection port in its receiver plus the trigger required different parts. I like the idea of a sub caliber/22 adaptor but I tend to think that if it was such a great idea we'd have seen it by now. Like 22 conversion units for centerfire semiautos-AFAK only Colt and CZ have oeffered factory units.
 
Anyone who wants to build a semi-auto bolt device for a conventional rifle is more than welcome to do so; the Pedersen patents have long since expired. Let us know when you have one working and we will watch the You Tube.

BTW, .32 ACP won't work well in a long magazine; it is semi-rimmed.

Jim
 
The Pedersen device was an attempt to make a semi-auto rifle out of an '03 for use in the trenches of W.W. I. Finances were irrelevant, but it worked. Biggest issue was primarily the logistics of another cartridge and the PBI having to lug mags etc around. And the fact the War ended.
 
You must log in or register to reply here.
Back
Top