The slant would help, but I don't think it will totally eliminate your problem. You are still funneling a group of paintballs down into the breech, and anywhere there is funneling like that you run into the risk of jamming.
The problem is that piantballs are a very finicky ammunition. They are too soft to really compress (like bullets in a clip). They tend to get sticky if it's humid, which makes them jam even more.
The reason companies like RAP4 build such a complicated magazine is because it is what works reliably.
2003 ICD BKO w/ 45/4.5k, Ricochet Apache
'98 r/f Autococker w/ 45/4.5k, J&J Edge kit (14"), Ricochet 2KX
PCS US-5 Mech. w/ 48/3k, J&J Edge kit (10"), cyclone feed, JCS folding voodoo stock with RVA
Kingman Hammer w/ 13/3k, J&J Edge kit (14")
Projects in the Works:
'99 r/f Autococker w/ 45/4.5k, J&J Edge kit (14"), and THE CYCLONE!!!