I would not make slingshot from 2x4 I believe they are from pine just not strong but, yousr might be different i dont know.Tubing? I dont know but any should do the job use them double if single cant do it.I Found a nice, mildly cracked piece of 2 x 4. I don't know what wood it is. What do yo guys think? would it make a good slingshot
P.S., Which thereatubes are strong enough to puncture coke cans? The latex tubing from home depot just doesn't do it...