glass barrels eh? take a look at the new pirhana barrel, clear. theyre made out of polycarbonates i believe, like bullet proof glass. now about this effective length, i understand that porting makes it less gas efficient, but does the porting really vent all the accelerating gas that early? wouldnt the severity of the porting also dictate effective length. like the 98 barrel, it has a ring of porting very early on, but is that venting area enough to blow off all that gas i dont think so. and the palmer theory, palmer is a very smart guy, but their is video where someone powdered the barrels and shot through it, and showed that a paintball rides on the 2 highest points, like rails. so palmers spoken like a man who doesnt makes different bore barrels. though he does have elliptical honing, which is a whole other barrel of monkeys

Frag'd, toe tagg'd and body bag'd,
hell son, you mustve just been automag'd