[Boberama]

Yesterday I came across a 20mm/.810 derringer on a Finnish site.
http://netti.nic.fi/~3072/pics/deringer.jpg
The original derringer,
http://netti.nic.fi/~3072/pics/Derringer%20side.jpg
The modified derringer.
http://netti.nic.fi/~3072/pics/Derringer%20front.jpg
Look at that barrel!
http://www.derringer.de/n-hel1.jpg
Shorter version.
Ouch!

Derringer.de claims a 30mm version is in the works.
It's also in 12.7mm/.50 caliber. The manufacturer is listed as Helenius, Pekka.

Ballistics are
a 296 grain bullet at 1300 fps OR
a 370 grain bullet at 1145 fps.

That works out to 1,111 and 1,077 ft-lbs of muzzle energy respectively, which puts it in the same energy class as a .44 Magnum, except with a bore almost twice as large. It's worth noting that the frontal area of the bullet is three and a half times as much as that of the .44!

The Finnish Special Weapons club claims that this gun is quite comfortable to shoot, although some of them shoot .50 BMG pistols, or so they claim, so their definition of comfortable could be quite different from ours.

Now all we need are some .810 hollowpoints and a suitable holster...

Here are my sources:
http://www.derringer.de/newi.htm
Click on the little symbol of the revolver for the ballistics.
http://netti.nic.fi/~3072/tietoja.htm
To see the .50BMG pistol click on .50BMG and go to the bottom image.

[earlthegoat2]

Nice Hogue grip.

[armoredman]

Words fail...

[memphisjim]

ouch

[Brian Williams]

I put this in the same category as the Taurus Judge.
Also ATF limits guns bore size to .5

[proud2deviate]

Words fail...

The one word that came to my mind was "Thwop!"

[MagnumDweeb]

<drool drips out of the sides of my mouth>, HOWW DO I GETTT ONEE!!!!! MagnumDweeb

[PTK]

Also ATF limits guns bore size to .5

No, they don't. You just have to pay for a destructive device NFA stamp after that if it's not a sporting arm. :)

[Gryffydd]

... .810 caliber and a 296 grain bullet?
Do the bullets look like this:
http://4.bp.blogspot.com/_Ae0Pt6UDPgw/SNmMQ4HRZCI/AAAAAAAAAdQ/3dX8jQ5Iwqo/s320/neccowafers.jpg

[DougDubya]

You'd need hollowpoints with an .81 caliber bullet?

Flatpoints'd do fine.

[brickeyee]

No, they don't. You just have to pay for a destructive device NFA stamp after that if it's not a sporting arm.

You will not be able to get an import license.

[damien]

You will not be able to get an import license.

Doesn't look too hard to manufacture here. :neener:

[9mm+]

Interesting curiosity from those Finns. The derringer (or the correct spelling, deringer) is a practical pocket firearm, but this 20mm monster is just plain crazy. It should establish some bragging rights for those who buy it, though.

[rondog]

... .810 caliber and a 296 grain bullet?
Do the bullets look like this:


Not to change the subject, but those nasty-tasting Necco wafers make excellent targets for .22 plinking, when they're glued all over a piece of cardboard.

[rcmodel]

A 296 grain bullet OR a 370 grain bullet.

Methinks they must be a machined aluminum ball or shot, and a very short aluminum hollow-base bullet to be that light in 20mm.

rc.

[Schofield3]

Not to change the subject, but those nasty-tasting Necco wafers make excellent targets for .22 plinking, when they're glued all over a piece of cardboard.

I've gotta try this now, haha

[Zoogster]

You would be better off with a 10 gauge handgun and just loading it with very moderate loads.
Slow and heavy. Use shotgun or pistol powders that are best for the barrel length while staying within pressure limitations.

The 10 gauge would be easier to purchase components for and it is just short of 20mm being 19.69MM.

Against unarmored targets there is something to be said for very large diameter projectiles even with moderate or low energy figures. Penetration is much less, but damage to what is penetrated is very high.
In fact a 20mm handgun is just taking the .45ACP concept or the .50GI concept to the next level.
Really slow, moderate energy (for the projectile size), but a very wide hole.
The target will also feel the impact much more than from your typical handgun round because it is more like being stabbed with a flat tipped 20mm metal rod than being shot.

Since handguns do not achieve the same wound profile as rifle rounds, as large a projectile width as possible while still retaining adequate penetration with manageable energy figures would be the most effective against humans which require limited penetration.
A 1 inch bore handgun that could penetrate at least 4-7" of tissue would probably result in much more 1 shot stops than a .40-.50 round that penetrates twice as far. Such a round would be easily defeated or severely reduced in effectiveness by even light cover or any body armor though. It would also be horrible at any distance, bleeding energy very rapidly and have a horrible trajectory. But since most self defense is within a few feet that is not a major limitation.

[Eightball]

Looks like it's be a cumbersome CCW piece.

[Dravur]

Holy Santa Maria!

I gots to have one

[9mm+]

Looks like it's be a cumbersome CCW piece.
I think it's unworkable as a CCW. That octagonal barrel has to be heavy and it's too big to conceal like a normal derringer. Unless the shooter was extremely proficient at drawing and firing it, which would be punishing in its own right, the weapon's effectiveness as a CCW would be nil.

[Dr. Fresh]

I'd buy one as a percussion muzzleloader.

[THE DARK KNIGHT]

I think a lot of people here have completely missed the point of this gun (and many others like it)

Not every gun must be for CCW

Not every gun must be ready at all times for the zombie apocalypse

Not every bullet must be a top notch defensive round

Sometimes, people buy guns just for FUN. Just to take it to the range and laugh. To say "holy crap! Look at this little .810 pistol hahaha! Try it out man!"

This looks like one heck of a fun gun!

[9mm+]

I fully agree, DK. It belongs in the "curiosity"/interesting-to-shoot category, not as a CCW.

[skoro]

hmmmm...

Is somebody compensating? :rolleyes:

[theotherwaldo]

Looks like a fun toy. Pushes the handgun envelope.

[Mandolin]

It's an .81 Magnum, it shoots through schoolbuses.

[Boberama]

According to their sectional densities, the 296 grain bullet is equivalent to a 92 grain bullet in .45 caliber, and the 370 grain bullet would be a 115 grain bullet in .45 caliber.
A 230 grain bullet in .45 is equal to a 739 grain bullet in .81 caliber, which would obviously produce excessive recoil.

[Mr. Bojangles]

All this math and I still want one!

[KBT1911]

Holy crap! Is that a Finnish 20mm in your pocket or are you just happy to see me?

[proud2deviate]

Kaliber: 30 mm ist in Planung

I may not speak Norweege, But it sounds like they're gonna try for a 1-up soon:D

[federalfarmer]

Hmmm maybe we should produce and sell 10g single shot pistols! :D

We could have them shoot 3.5 inch shells loaded with OOO buck, full power. :what:

To be tacticool add some rail and a surefire light, maybe some nv.........!

[mustang_steve]

Yep, this gun definately falls into the "fun things that go boom" category. Pretty much something for some shooting range fun...I figure watermelon shooting would be really amusing with this monster.

[JohnnyOrygun]

Gives new meaning to the term "Hand Cannon", just needs wheels. All I can say is...
OUCH

[rogertc1]

My Downsizer in 45ACP is painfull to shoot. I bet that 20mm would almost break my wrist!!!