Eagle6 and FS sold out They aren't that special by the way - I wan the W-hold on and off for years and, well, you can do better with flat hopping and R-hopping these days pretty easily.
I may try flat hopping then, should have an EDGI barrel coming, already got the AA chamber so might get hold of a Nineball or stock TM and give it a go
I think I PM'd you about this, but if you go the flat hop or R-hop route then certainly go for a VSR bucking - the lips on them make a better seal with the cylinder. I'm not hugely familiar with the EdGI barrels but I assume he's been putting the VSR grove in them as well as the AEG ones?