In the V2.2 rulebook, the L85(IW) is listed with a 20 cartridge magazine in the Small Arms Firing Chart (pag. 254) and in its own specific card (pag. 104). But in this same card, not in the game statistics line, but in the column just above it, it comes listed as use both 20 or 30 round magazines. So, I suppose that the L85 can use both type of magazines. I suppose the 30 cartridge version is the most used.
In Paul Mulcahy pages, (with permission
) the two versions of mag. are listed.
http://www.pmulcahy.com/assault_rifl...ult_rifles.htm