thanks MPeltier. some good pointers with chamfering bbl and gasblock and credit card thickness. I did get the rifle to work! I went back to the standard carbine gas tube. In the photos that is a "fat tube". Before assembling the topend I would blow into the gas tube and take notice of where the air stops and begins into the bbl gas hole. Having that credit card thickness is about the right spot for gas flow.
I dont think I had that space before, it was up against the step. When I removed the gas block prior this replacing the gas tube, you can see the discoloration from under the gblock from the gas escaping.
Now there is no gas escaping at all. The gun is a 16" carbine length gas with a rifle stock/buffer and JP buffer spring. Full weight BCG.
Shooting extreme 55grs, 26.0 grs H335. From my last chrono test is was near the 3000 fps. A fellow shooter shot up my chrono for now.
Had I know about the chamfering bbl and block, I would had done that, Seems to make sense.
thanks to all, am learning )