Solid inserts of good length. Excellent quality. Tightening tool.
Poor self cleaning. Heavy.
Let me start off by saying that I much prefer single tube barrels. The reason I have started to use a multi bore system is out of necessity. My FPO paint has been averaging 0.680 and there is no single bore barrel that size that I can find.
Buid quailty is excellent. The entire kit seems very solidly built. Inserts are aluminum and stamped with the size. The back looks like chromed stainless steel. Quite beefy and as a result this kit is the heavy barrel I have ever used save for a 12" DYE stainless. The tip is a ported aluminum piece completing the 14" system. Too bad they didn't offer any other tip sizes. The interior finish is top notch.
Insert bore size availability is great. Staring from 0.679 all the way to 0.695. Never calipered the inserts, but based on the build quality of the entire kit I would assume it is accurate.
The insert and tip are reverse threaded. Takes a little getting used to, but who cares, it's just threading. A tool is provided to tighten the barrel to the gun body, no more stuck barrels!
The barrel kit shoots fine. No better and no worse than the multitude of other barrels and kits I've used. With the large number of ports it's sound signature is reduced though I have used other kits where the ports were smaller and the sound was even more muffled.
This barrel kit does NOT clean well. Self cleaning is next to non-existent, expecially when I'm using such small paint and the tip bore is so big. Looking down the barrel, I can actually see 3 stages to the bore. Paint gets stuck in the middle stage and cannot be clean out effectively. The large ports on the tip make it impossible to blow out the ports via dry firing into a bunker as well.
The product is decent, but there are better kits on the market. I enjoyed my Powerlyte Scepter kit much more (lighter, quieter, comes with a carry case). The only downside really is weight and self cleaning ability. If you don't break much paint then this is a non issue already. If you get an unbeatable deal on this kit then go for it, otherwise get something else.