My thought is that the EMT will have a rougher inner surface than you want. It is welded seam pipe. It is heavier than you will prefer. If you remove the interior coating it will corrode more than you will desire. If you want to get started on the cheap I would recommend schedule 40 1/2" 1120 series irrigation pipe from Home Depot or Lowes. buy a 10' length for $3 and graduate to a commercial blowgun when you know you are hooked. Either way you will need to make your own darts and will be limited to either low quality darts or to high detail work to create better than commercially available darts.
1/2" irrigation pipe shoots miniature marshmallows decent to about 20' but accuracy is not available in such a setup.
You might want to price out high quality blowguns. In my opinion those are available for under $40 with enough darts to get you started.
All the best in your quest.
1/2" irrigation pipe shoots miniature marshmallows decent to about 20' but accuracy is not available in such a setup.
You might want to price out high quality blowguns. In my opinion those are available for under $40 with enough darts to get you started.
All the best in your quest.