The Space Cannon 308 pistol

Sig barrel 12.5in
PSA Space Cannon lower
PSA stripped upper
Midway lower parts kit.
Keymod 12in rail from LGS
PSA adjustable brace.
Cheap Monstrum Tactical 2x7 scope

1st target 190 gr hertenburger match
2nd target PPU 168gr match
Targets were at 95 yds. Just off bipod no bags
Mil spec trigger.
It will do for a truck gun


149 gr ball surplus. 2 groups same distance
Adjusted scope between groups.


That’s awesome! I’d say it’ll more than just do!!


I know it’s a space cannon, but, can we get a pic of the whole gun?:rofl: or is that classified?:upside_down_face:


Knew I forgot something.




Oooooh, that’s a beauty sir!!


Didn’t turn out too bad. I am happy with it. The 190 gr match ammo thumps your shoulder a bit. I might try an adjustable gas block. I did open the gas port up a little. With the short barrel I was seeing muzzle flash through the scope even w/the flash can on the muzzle break. That’s on a bright day and not in the shade. I will have to shoot it at night without the flash can sometime.


Very nice!


I’ll take 2 please!


CDNN has the barrels for $49.00.
Build you one or two or three. I have just over $500.00 in this one and that includes the other barrel I have.


“Only fits Sig Sauer 716 rifles. Will not work with any SR25 or AR10 platform.”

:confounded: I’ve already bought all the rest of the parts for DPMS LR308 pattern. Oh well.

What size gas port did it come with? I’m probably going to cut and reprofile a barrel with rifle length gas system down to 10.5" and a carbine length gas system.


These work just fine. You just need a custom gas tube. Several people over on have built these. The Sig was a piston gun. We are making impingement guns with the barrel. White Oak Armament makes custom tubes. Not sure what the gas port was. 1/16 bit was too small and 5/64 opened it up just a bit. I am more interested in the gun functionality than recoil.


Then the chamber end of the barrel is compatible with DPMS LR308 parts?

I may have to try one.



Yes dpms pattern bolt works just fine.


Very nice Brother!!! I like it a lot!


Package was waiting on the porch, when I got home. I haven’t installed it in an upper, yet, but holding it next to a barrel with a carbine length gas port, it looks like the gas port location is the only oddity, and it’s in a spot that should be covered by the gas block.

After testing the fit with my upper receiver and bolt carrier assembly, I think I’ll cut it to the 10.5" length I wanted, recrown and thread the muzzle, then drill a new gas port at the correct location.

Thanks again for the info! That cuts a lot off the cost for this pistol build.

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Just curious are you going to have enough dwell time to cycle the action going that short? I know my FAL pistol had a 8in barrel but that was a piston gun. Pretty sure there is a reason there are not a lot of really short ar style 308’s on the market. If you go with a pistol length gas system you will probably need a custom made gas block. I’m not saying it wont work this is just some of the potential problems i see.

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The standard location for the gas port on a carbine length gas system is a little over an inch closer to the chamber, than where Sig put the gas port on this barrel. That should help with any issues from cutting two inches off the barrel.

If it doesn’t work out, I’m only out $49, which is less than I spent on some other projects that didn’t go as well as I had hoped.

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