I emailed superlative arms about possible 0.625 and got a very awesome reply. If anyone knows who these guys are they are the manufacturers of the syrac ordnance piston kit and own/coown patents on the kit.

It's coming soon, Tony said they're about 5 weeks out with production, processing, and qc for the 0.625 kit with an ETA of roughly 6 weeks and mid March is the ETA for the 308 kit.

I'm excited. Here is a pic he sent

capture screen

Guess I should hold off on buying the 0.750 kit.

They will be attending the shot show 2016.

I just got off the phone with Tony and I have to say their customer service has been, well.....Superlative.  I'm really impressed so far and can't wait to get my kit up and running.

Right? I was thinking the same thing.

You're getting the 0.625 kit or 0.750??

^Same here.

After placing my order I had an issue pop up.  I got on the computer to email Tony and he called me as I was typing out my email - problem solved.  

I found out about Suparms after reading one of your posts Keith1980, so thanks for that!  After reading and researching I decided to try a piston setup for my latest build instead of an adjustable GB, which I was going to use initially.