The amount of antimatter contained in the ammunition would be quite low, certainly less than a gram, due to the method in which it is contained and the size of each casing. You're simply looking at something that acts like an explosive bullet on a slightly larger scale, and is quite obviously feasable as a weapon.
Incidentaly occam's razor just makes things less likely to go wrong. Complexity FTW.
Incidentaly occam's razor just makes things less likely to go wrong. Complexity FTW.