[KAGE]

mriddick, I just shot the one I built today. its a 7 1/2 inch barrel. I had a problem with short stroking which I attribute to the "pigtail" gas tube. I'm putting in a straight tube and will try again. the buffer is a pistol (carbine) sized setup. if your OAL is 26" I'd just build a carbine and be done with it.

 

[KAGE]

mriddick, I just shot the one I built today. its a 7 1/2 inch barrel. I had a problem with short stroking which I attribute to the "pigtail" gas tube. I'm putting in a straight tube and will try again. the buffer is a pistol (carbine) sized setup. if your OAL is 26" I'd just build a carbine and be done with it.

I goofed. 26" is an AK with a folding stock in the folded position. an AR with a carbine stock collapsed is 32". my pistol with a 7 1/2 inch barrel is 23" overall. IMO shorter is better. it will be nice to get the bugs worked out of my build so it runs good. muzzle blast is another issue but it cannot be helped with such a short barrel.

 

[KAGE]

the pigtail gas tube encircles the barrel twice on its way to the bolt carrier. a rough measurement comes out to 5+ inches added to the length of the tube. a straight tube is 7 inches. the pigtail is about 13 inches if it were straight. that is longer than the tube on a mid-length upper. I don't think its building enough pressure before the bullet leaves the barrel to work the action properly. I will keep you informed on how this works out.

 

[KAGE]

I purchased a straight 7" gas tube for my pistol to replace the "pigtail". everything works great now. I just got back from the range. 100 rounds in 20 minuets the only stoppage was from a P-mag I tried. god awful muzzle blast though.
nice range toy. so NY50/70 I'd say 7.5" is reliable.