Finish question regarding the female barrel threads - do any of you find you have to put 2 o-rings on your barrel back? I played with one o-ring the other day and noticed some vertical slop with my barrel tightened down. So I threw on a second o-ring and it cleared up almost all of that slop. Do you find any issues having 2 o-rings on there with the gap between the barrel and the eye pipe?
I don't recall ever having this issue on my DM12 so I am assuming it's a machining flaw or something similar.