I think the RAP4 mags have a trip on them that doesn't release the spring pressure until you load the magazine into the marker, which helps keep you paint from being ejected out while you are carrying it.
Maybe finding a way to mod your AB to use RAP4 magazines will be the better way to go. They've already done the work on designing reliable magazines.
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!!!