German members and others: 4mm M20?

[NonServiam]

Buying a magazine for my Beretta 71 (sweet little thing, especially with the silencer ) from a German website, I came across the 4mm M20 calibre. Can anyone tell me more about it? German members or others?

Is this a widely used training calibre? My knowledge of the German language is a bit rusty, but are the 4mm M20 guns not registered, considered to be similar to airguns in that respect? Seems a lot of the guns on this site are rechambered/rebuildt for the 4mm ...

 

[Jim March]

Hmmmm. Interesting. I'd like to know what's up here too. I can just imagine a wildcatter necking 45-70 down to 4mm and driving a 50grain projectile about 3" long designed to wildly destabilize on impact when hitting at around 5,000fps......

 

[Marko Kloos]

4mm M20 is a very weak rimfire round, a 4mm lead ball sitting on a very short rimfire case. It generates just a little more muzzle energy than your average air rifle. Per German law, you can buy handguns converted to 4mm M20, although you still need a WBK (weapons possession permit) to purchase one. The difference is that you don't need to prove "need" for a WBK like you need to do for bigger calibers.

The conversion is a permanently installed barrel sleeve, and the guns come with adapter cartridges.

 

[otomik]

found some chart that says it launches a 8gr BB at about 950fps, is this even enough energy to cycle the action or is it a revolver only thing?

 

[KRAUTGUNNER]

Marko is right about the 4mm M20 ammo.

It is a weak version of the .22 BB cap.

It's energy is limited by law to 7,5 Joules (5,5 ft. lbs.).

 

[EvilOmega]

It's a special stealth round, you shoot someone with it and they don't notice.
If you have a choice between a 4mm gun and a knife, it might pay to take the knife.

 

[NonServiam]

Thanks guys! I was just curious

 

[Dan Forrester]

NonServiam:

How do you attach the suppressor on to the Beretta? I assume it’s a muzzle can, so must be by means of a threaded extended barrel.

Where does one acquire such a barrel for a model 71? Right now the only good pistol for which I can find extended threaded barrels is my Beretta model 21 in .22 lr.

BTW: What kind of suppressor do you have. Mines a Gemtech Vortex II.

Thanks, Daniel Vaughn