I'd discount older markers as bad designs........ they had to try stuff out. To me a bad designer has to "know better" and still make a steaming heap of poo........... PT pistols......... now there's a worthless hunk of crap.
Load, vent, load, vent, load, vent, manage to gas up......fire two balls..vent......load....powerlet goes supersonic........... return for refund.
what a crock.