I currently use 7 Low cap mags for my P90. I use an dropleg to carry 3 mags plus 3 in a carrying pouch+ 1 in rifle. But I came across this little web site for all you p90 nutz
http://thevestguy.com/category.asp?id=169 While I was researching for an Stargate loadout for future planning. Something I am considering to buy soon.
cheers