None,but i hear that the Flatline barrel is great.
US Army/ Tippmann Alpha Black Tactical Edition
Apex BT47 Barrel
(Not much but then again, there aren't that many mods for the ABT yet)
I've only used CamoTacs. Haven't had single chop or a break in the barrel.
Ability to curve shots
Takes time to perfect it.
Setting #8 is not very accurate
My gun feels heavier
So.. i'm a beginner but i think i'm getting addicted to the game rapidly.
Having said that.. I LOVE THE APEX BARREL. The last time i used it i took 3 shots, two to know where the balls are breaking and the 3rd to take a player out... and it worked like a charm. I was shooting on the #6 setting and the shot was close to 200 ft. It was accurate as hell !!!! I was able to take out at least 4 guys who underestimated the range of the gun.
The 1,2 setting works like a normal barrel. I didn't use the 3,4,5 settings. When i first got it, i tried #8, accuracy went out the window. the ball was curving out of control but the range was clearly more than 250Ft or 300Ft. But i figured 6 would be the perfect setting and it was.
The only downside to this was (on #6 setting) that it was heavy and hard to manage during quick situations. i mean the ABT is heavy as it is and this barrel easily added another 6 inches and a couple more pounds to my gun.
I still love it though. I love the range and the accuracy it gave me and i shot a guy in close range and he got a wicked scar on his thigh! I mean like a full on bleeding, swollen scar and he was amazed it was that bad. I'm pretty sure the barrel contributed towards the initial velocity carried all the way during that shot.
If you want a cool looking and a VERY functional barrel, get the Apex BT47. It works like a charm when it comes to curved shots and you can surprise the hell out of anyone who thinks they're out of range. i'm giving it a nine because it's not very easy or quick to adjust the barrel during a game and the #8 setting doesn't always give you the best accuracy.