Out of spec parts at RA? Say it isn't so! LOL.....Since RA released the Type 3 gas blocks, I've been a big fan. More adjustability, tuckable and works much better with suppressors. Early on, I found that I was able to run on setting 0 and turn my XCR into a bolt gun. It was great with the suppressors because it really cut down on the gas face.
I got my 18.6 Grendel barrel a few weeks back. Type 3 block. That barrel gave me significant gas face and would cycle enough to chamber a new round most of the time, on setting 0. A short email exchange with RA basically said that 0 is the lowest setting and won't turn it off. OK.
I swapped out an early Type 3 block from a barrel that I knew I could "turn off". I put the older block on my Grendel barrel and with that older block, I can "turn off" the gas on the Grendel.
I'm guessing they either changed the spec or they aren't paying close attention to the spec from their suppliers. Some of this may be the difference between a "762" dial and a "556" dial but I would think that regardless of the dials, they're both completely occluded on setting 0. Just eyeballing the hole in the block that covers the barrel gas port, it looks like there's a difference in the size of those holes. Looking down into the block, where the piston enters the block, I "think" there's a difference in the dimensions. That's just based on eyeballing it. I haven't had time to tear them both down side by side but there's clearly an operation difference between the 2 blocks I swapped.
I'll update as I find out more.