Constant A-5 ball breakage

I was wondering if someone could help me out with a problem I have been having with my A-5. I am fairly new to the sport so please forgive me if I dont know all the terminology. I bought a brand new A-5 from a reputable online Tippmann reseller and it was a stock A-5 but I added the flatline barrel, adjustable stock and remote hose. The gun had been constantly breaking balls since I got it. I have been using Marballizer paint (the highest grade paint I could find) which was stored at room temperature. There doesnt seem to be any breaking in the chamber or inside the cyclone feed, only in the barrel. I do not believe the barrel to be dirty or having any burrs because it still breaks paint just as often with the stock barrel. I am running a 68ci 3000psi high pressure tank to the marker. I sent the gun back to Tippmann and they replaced the bolt and an o-ring and I still get the same problems and I was very thorough with my explanation of my problem. I broke the gun down myself to look for any broken parts but everything seems to be in order. Can anyone give me some advice? I tried to be as thorough with my explanation as possible but let me know if I forgot anything.

The velocity is set to about 270 (although it is pretty inconsistent) Im using Evil paint right now and its doing the same thing. My friend has an A-5 with flatline and he says he almost never gets breaks even when using crummy field paint. This problem still occurs no matter what type of paint I use. (ive probably had 5 different types in there, all different grades)

Marballizers are fine with the Flatline.  With the Flatline, you want small-bore paint.

My first guess is the stock.  Take off the stock, put on the regular endcap, and see if that helps.  Then take off the remote and put the tank on the gun.

If that doesn't help, take off the Flatline and try the stock barrel.

The Cyclone could be the problem, but I'm guessing air supply.