when I first got mine it was trying to keep it tight was the problem, after a few shots it has now settled down, the rubber o rings are the thing to be careful of, I use a bit of tape as a grip on each segment, and give it a good clean out, refit together carefully and don't pinch up the o rings, haven't had any signs of wear yet. A1 so far
They really are a stalking mod, if you use them on the range for a lot of shots I don't believe they will have a long life, aluminium and heat don't really mix
Phil