Chopping and HPA usage

With the help of my friend who has done upgrades on several 98s and a few A-5s, for his friends and family.  I had a new power tube from RAP4 installed on my A-5, and using a Pure Energy 70ci, 4500 psi high pressure tank as the air system.

Everything seemed to fit inside the gun with no additional modifications such as sanding, however when I shoot the gun out of 10 shots 2-3 are barrel breaks.  I take off the second part of the barrel and it didn't break the paint for several shots.  There is nothing rigid inside it so I don't understand why it does that.   Last year when I used my gun i had no issues with chopping, but I ran off CO2 then as well.

Also with a possibly related issue, my gun was blowing through my tank.  I started off with 4000 - 4500 psi in the tank.  After firing 3/4 the hopper it lost 1000 or so.  I fired off 2 hoppers worth of paint and it was around 2100, just above the 2000 mark. 

I left the tank on my gun drove home and checked it about 30min later and the indicator didn't seem to move, so it doesn't seem like its leaking.

Going to take it to the local shop to see why it might be not working, but was hoping someone might a quick idea which could cause the breakage and it eatting air.

I also have a response trigger on my A-5.
Its all stock except for a Shocktech Drop, RAP4 powertube, All American Barrel, Compressed Air.  I had no issue with it last year and CO2, other than inconsistent shots, which is why i upgraded powertube and air.

I played a few games, before I bought the A5, with my friends Tippman 98.  It was a really good gun, so I wanted to buy my own.  He told me to get A5, because it had the cyclone feed and a few things to make it better than the 98.  His 98 has only had the power tube replaced and fed with compressed air as well as a drop kit.

When I used his 98 it felt pretty accurate and I liked the gun a lot.  But when I got my A5, the only thing nicer was I didn't get any barrel breaks, cyclone feed is nice.  It didn't feel as accurate and nice as his 98, so I thought getting some of the same simple upgrades might make it shoot more consistent and accurate, which is why I got compressed air and the power tube.

The issue might have been the paint, because we were using some older paint from an park event last fall.  However, my friends 98 and his brothers shocker did not break any of the paint.  They were shooting a couple hoppers worth. Mine was barrel breaking quite often.  However when I took it to a local paintball shop, they fired some of their stuff and none broke.

It seems like the 98 is gentler on paint...

I put my old Pure Energy 20oz CO2 tank, fired off a hopper of Diablo Formula 13 paint and none broke...  It worked well too... I didn't remove the Power Tube. So it could be the paint or the tank.

I think its mostly the paint quality... The paint I was using was from a park called EMR in PA, does Castle Conquest, they are Monsoon by JT I believe....

Ill just use the CO2 tank on the A5 from now on, I have a Smart Parts Shocker as well, and will just use the HPA on that one..