New 22 up and running, mostly

[Plastikosmd]

1919 browning built by John Mcguire
22 conversion, 1.5 yrs in making by belt-fed-plus aka Thomas Heim
Bolt conversion to semi auto again by Mcguire

4hrs of fun today learning my way around this thing. Still a bit to do. It needs the power of minimags to run via recoil. I had a few blown case heads. I need to lighten the firing pin spring as it is piercing the cases at times. You can see this in the comparison shot. It really dents the heck out of the rim.





How the belt feed works. There are adapters, clips at end of each pair of adapters, dummy cases that then fit into spring adapters in belt


A blown one


Blown vs not, heavy impact though

 

[Plastikosmd]

A look at the 22 converted /machined bolt(right) vs 7.62 (left.)A lot of metal missing




Also cleaned off the 250 adapters and sleeves
Now to start putting in belt. My poor fingers..

 

[The_Next_Generation]

We DEFINITELY need a video! Never seen something like this before. More pics would work too, I suppose. What do the insides look like?

 

[Gordon]

One of the kewlist things I've seen ! Thinking about it it certainly makes sense to me. Congrats

 

[Plastikosmd]

Inside, there is a small barrel adapter sleeve to mate the 22 barrel and custom muzzle retaining nuts to the accelerator. There is a feed adapter and that is about it. It only takes a minute to switch it out and back to 7.62

 

[bannockburn]

Extremely cool and amazingly ingenious!

 

[agtman]

Nice! Thanks.

 

[Vern Humphrey]

Hmmm . . . think he'd do an M1917 watercooled MG?

 

[chicharrones]

Wow. Very, very impressive.

 

[MachIVshooter]

Cool toy!

That bolt, though.........holy toolmarks, batman! I'd never let a piece leave my shop looking like that.

 

[ironworkerwill]

Cool toy!

That bolt, though.........holy toolmarks, batman! I'd never let a piece leave my shop looking like that.

Well, not everyone is the "Van Gogh" of the end mill.

 

[MachIVshooter]

Well, not everyone is the "Van Gogh" of the end mill.

Yeah, yeah. Lol.

Still, it looks like dude was running a plum wore out cutter at about 100 RPM on a sloppy old machine and couldn't be bothered with a finish pass.

If you can't make the tool marks look clean & uniform, get busy with files and stones!

 

[jmorris]

Still, it looks like dude was running a plum wore out cutter at about 100 RPM on a sloppy old machine and couldn't be bothered with a finish pass.

They don't care about that part, loosing weight was the goal. The surfaces that ride against one another are the ones important here.

Look at the machine work of the two piece adapters, that allow a .22 rimfire to cycle the still very heavy reciprocating mass of the "lightened" part, that's the most important "fit and finish" in making them run.

Not uncommon among machine gun parts, they were built with function in mind over finish.

Like the original Powder Springs bolts that were lighter than the later bolts.


I guess they lowered the rate of fire, reduced machine work and eliminated the extra tooling marks all at the same time.

 

[fireman 9731]

Full auto or semi? Either way, squirrels beware!

 

[Plastikosmd]

semi, yes, it is fun. it will be more fun once I get belts set up