Portable 6mm Semi

[noname]

This is my second 6mm semi auto, but this one actually works. It was very surprising to me, because I can never get anything aligned perfectly. I haven't shot with the barrel yet, but hooked up to unregulated propane, it can dump a 20 round mag in less than 5 seconds and shoot the BBs about 10-15 feet. This gun would be extremely simple if not for the blow forward bolt. A single shot version of this would be a piece of brakeline, a blowgun, an elbow, and a quick connect.
Instead, it uses (going from gas tank to barrel)
Propane tank
Propane Adapter
Female QC
Male QC
1/4" street elbow
Blowgun
1/8" close nipple
3" section of 1" Sch 40 PVC
1/4" aluminum rod
Solid Epoxy as a plug in the back of the PVC
Solid Epoxy bolt, with 5/16" and 1/4" brakeline
Spring
1" female adapter
1" plug
5/16" compression T
A couple mags made from a compression olive, nut, and 5/16" tubing
5/16" brakeline sleeved over 9/32" brakeline

I may add a stock to the gun, which is why I have part of the aluminum rod sticking out the back. I may also add a small BB shotgun underneath the barrel, as well as a rifle scope on top. I will almost definitely paint the gun (flat black).

It's not as cool as Jack's clear syringe for a blow forward tube, but a plastic syringe costs me almost $5.

[VH_man]

damage? FPS?

and i think you should add some kind of hop-up.

anyway, nice, its basically a dummed down version of jacks that allows EVERYONE to build one.

im building one of marble calibre sometime............

[mopherman]

looks great. I would have used a longer barrel because of the slow opening blowgun. does the bolt ever jam inside that tee?

[noname]

I haven't shot with the barrel yet

I forgot to mention the little hopup/ball stop. It's a tiny sliver (literally) of a rubber gasket which protrudes from the top of the T.

its basically a dummed down version of jacks

Thanks a lot.

You try making one; getting all those tiny parts right is bitch!

[noname]

looks great. I would have used a longer barrel because of the slow opening blowgun. does the bolt ever jam inside that tee?

The barrel is 30" long. I guess I forgot to take pictures of how long it actually is.
The bolt has never jammed, but it occasionally knocks the 1/4" aluminum rod back. This is also why I'm not shooting it right now; I'm waiting for the epoxy on the rod to dry so it stays in place.

[iPaintball]

It's just like mine, except, 20 times bigger. I made one for .177 bbs out of a bored out 1/8" tee. I used a piece of a small spring as the bolt return. Now, THAT was a PITA!

[jackssmirkingrevenge]

Well executed, nice to see the use of epoxy looking forward to seeing videos of it in action.

[iPaintball]

Ehem, where are my manners? Well don old bean! Is that marine epoxy?

[noname]

Jack, I'm never going to have any videos of any of my guns, strafers or otherwise. It sucks major balls, but I don't have a video camera or near enough cash for one.
iPaintball, it's just regular Ace Hardware 2 part epoxy, nothing special (except it's 60 minute epoxy and took around a week just to dry )

[VH_man]

if it took that long to dry then you didnt mix it right..... i have Epoxy that NEVER dried.

[noname]

I did mix it right, because I inject it through 2 syringes, each with graduations of 1 mL on them. For tin ythings, I usually mix around 4 mL. Larger things, like the plug, took 15-17 mL of each. And yes, the ratio of resin to hardener IS supposed to be 1:1.

Updates:
Mounting a rail right now, to put a scope on.
Made another magazine; I have 3 now.
Adding a new hopup, the bolt spit the old one out.
Attached a new brass barrel that isn't bent like the previous aluminum one.
Making a stock out of aluminum rod.
Might make a handle or a place to put my left hand (either that, or make another and dual wield ).

[hi]

well im impressed. (i wish i had more to say)

[windshrike]

Nice build, but somehow, JSR's 415 fps appeals to me more than yours shooting bbs 10-15 feet.

[noname]

Taking into consideration that he has a 2-3 foot barrel and mine is about 1/2" may broaden your thinking....

[windshrike]

Oh crap man, I'm sorry, I thought your barrel was just cut off in the pics.
I like how it can be taken apart, with JSR and epoxy it's it works forever or you're screwed.