Our arsenal covered only the small pistol sized nerf guns. These blowpipes were certainly more powerful than those.
But of course: it all depends on your lung capacity :-)

fieldm

Cool idea! Are they more powerful than the spring based blasters?

mudbloodvonfrei

tech

Discussion: Arms race at the office

PVC electric conduit pipes can be used as nerf blowpipes (16mm, ~20cm in length - don't know the imperial units for these).
Cheap, stealthy and can also be easily hidden in sleeves.
But be careful with these as they can come in hard...