I would use at least a 5-7foot length bg, carbon fiber dart shafts with light vinyl tape cones and aluminum nail tips. This should make a nice light dart setup. This would be my preferences..but others might have more suggestions.
A carbon shaft and lightweight cone sounds reasonable to me but I associate long distance with outdoor shooting. If you'll be in the wind, a heavier tip and more dart weight might be more beneficial. What are you planning to use as a backstop?
I can successfully shoot a soda can at about 30m with my current darts. I'm using my 4ft CS with 3" steel nails and a new cone method. Thick duct tape as the inner cone and thinner colored duct tape on the outside. I'll upload some pictures and video soon
The weight of the dart most suitable depends on that energy can impart, by firing distance, the type of dart that uses. Paper cones? I made a spreadsheet to calculate ... so you can know what is the weight of the dart that you get the maximum range
Sorry guys, the IFA recognizes using standard target darts from a standard 4 ft. barrel for long distance shooting. Jeff Boumier of France holds the officlal IFA world Record (I think it was 60 meters ???) back in 2010 or so. The French national organization has disbanded since then.
Target face was 24 cm diameter, only need to hit 1 of three darts shot. Bruce Bell of the USA held the first WR, 46 meters. Both used standard, store-bought 0.40 cal. target darts ( 0.8 gm weight). Official rules - start shooting from 20 meters - standard target height above ground, center of the target fce at 160 cm (5 ft 3 in.) shoot 3 darts, one must stick. If it does, move back 2 meters (@ 6 ft), and do it again. Round robin, last man standing wins.
Google "The breath of Zen" - also in France - if you want to really see long distance dart shooting at its perfection .... 80 meters!
http://www.sarbacana.com/sarbacane/englisch_version.htm Blowguns are caron fiber, range from 1.8M to 2M (about 71 to 79 inches), are 0.68 cal. Weight is 200 gm. Darts are film cone style. 10 to 30 gm. 11.8 inches long. (This is used to teach Zen breathing, not for competitive target shooting or hunting - however some of their ZenMasters are amazing shots - 10 gm darts at 93 yards). From what little I can read in French, they do not sell their equipment to non-students. You must go to their school, and the equipment remains onsight. They have had a lot of offers and inquiries, but hold fast to thism since the blowgun is a means to an end, not an end in itself. Very transcendental.