Forgot to post the finale on my M4 "RS" build.
Been using it for 5+ games now and finally happy with it.
Tried a bunch of barrels and rubbers but finally ended up running a prommy 6.03 barrel and a prommy purple bucking. Now it goes straight and as consistent a GBBR can (I think)
Externally there has been zero issues, but internally there has been some.
1. Almost smashed up my bolt against the upper ring on the ... lower. The RS buffer tube is a bit longer internally than the TM buffer so the bolt travels to far back and hits the lower. Spacer in and that problem was solved.
2. Guns modify nozzle v.2 has been acting up. On several occasions the nozzle valve either gets stuck completely or to much resistance making a jump from 1,75 joule to 2,6 joule and over-gassing everything. Stock TM nozzle rectified the issue so far.
So a final post with pics on it. If you have questions regarding the re-threading etc feel free to ask. I will answer as soon as I see it.