What's the Difference Between The Apex and The Flatline Barrel?

Both the Apex and Flatline barrel are upgraded barrels for your paintball marker. The Apex is an interesting little attachment; it has a switch on the side that will allow you to curve your shot one way or another. It's supposed to also increase the distance of your shot somewhat. It has to be used on a rifled barrel though for it to work best. The barrels that come standard on most paintball markers aren't rifled, so you will first need to upgrade to a rifled barrel before adding the Apex. The Flatline will not curve your shot but compared to the Apex, it should shoot farther and straighter. Whereas there's more tricks you can do with the Apex, the flatline seems to have a larger ground swelling of testimonials behind it saying it's the best. The Flatline barrel, however is made specifically for Tippmann paintball guns and may not fit on any others.  Between the two, if you already have a rifled barrel on your gun, you may want to see what the Apex can do.  If you have a Tippmann paintball gun and you're just looking for more distance and a straighter/more accurate trajectory, try the flatline.  Tippmann markers can use either barrel (the Apex dependant on having a rifled barrel to attach to first of course).  If you own a Tippmann paintball gun, you're simply missing out on one of the best upgrades in paintball without the Flatline barrel.