Irons use tbow on Zulrah, Cerberus, Armadyl, and Abyssal Sire. Best to get that tbow first, then keep working out boss slayer and collecting all the drops you need from those monsters, and in all honestly, having an iron as well, I'd say get that blowpipe pretty soon, it's veryyy useful for boss slayer, as well as the magic fang, and serp; if you happen to get them along the way of the bp. And if you ever need a break from pvm, work on fishing/cooking because as an iron you can always use food unless you buy potatoes with cheese from the warrior's guild.
