spudtech rifled barrel tests
"Increase Accuracy and Safety with Rifled Barrels.." is the claim we investigated. After our extensive tests, we at Burnt Latke would have to agree. The rifled barrel delivered improved accuracy and tighter groupings, especially at long range. With accuracy comes safety. The rifled barrel causes the potato to spin, stabilizing flight and reducing tumbling of the slug. This helps to eliminate the wild, spiraling and inconsistent behavior exhibited by the smooth bore barrel. To purchase your own rifled barrel or for further information on ballistics, visit the links below.
An interview with Joel Suprise, owner of the Spudgun Technology Center.
BL: There are many good things to talk about. On top of the list is the construction. The 2"threaded fitting used is top quality. Could you tell us the manufacturer?
Joel: "Dura Manufacturing."
BL: The 'channeled' sleeve used inside the 2" male threaded fitting positions the barrel perfectly straight. The sleeve is also missing some of its' extra plastic giving it a smooth, finished look. What's your technique?
Joel: "It's just a bushing that I turned in my lathe to fit clean and flush."
BL: The breech knife you suggested works great. Loading is clean and extremely fast. The rear of the barrel extends into the chamber positioning the spud about 1/2" from the forward electrode on our L1 launcher. This places the spud very close to one ignition source. This question only applies to forward mounted electrodes and assumes the exlosion / pressure wave is spherical. Do you think the close explosion might begin to push the spud down the barrel before the full pressure from both explosions has reached it's maximum?
Joel: "It all happens too fast"(to be of consequence). "The pressure rise in the chamber will be the same at all points inside the chamber."
BL: Getting back to the barrel, The supplied knife edge was only beveled on the outside edge. This caused our spuds to split after 1/4 of the cut. The slugs and the holes left by them were tapered. A hiss of propane could also be heard leaking past the spud in the barrel, possibly as a result of these tapered slugs. Is the Spudtech barrel tapered on one side only for a reason, would a slight inside taper interfere with the engagement of the spud into the grooves?
Joel: "A slight inner taper would be fine. I do put a slight chamfer on the inside edge of all my barrels. A slightly more aggressive inner taper may be beneficial...but too much of a taper could give you problems. As for the spud splitting as you jam the barrel through it...that's just the nature of the beast."
BL: Is there a recommended potato size for the 1.5" rifled barrel?
Joel: "As long as the spud is bigger than the barrel...you'll be fine"
BL: Could you tell us a little about the machine and process used to create the rifled barrels?
Joel: "Sorry...all I can tell ya' is that Ed Goldman built it, I improved it, and it is very large."
BL: Is there a calculated angle to the twist of the rifling?
Joel: "...just needed enough twist to make the spud spin. Too much twist and the rifling shreds the spud on the way out."
BL: What is the largest size of pipe you can rifle?
Joel: "Two inch pipe is the max."
BL: Is there a big difference between the deep grooves used on sch80 vs the traditional grooves of sch40?
Joel: "The grooves on the sch 80 are just a little bit deeper."
BL: Thanks for the info Joel, The SpudTech rifled barrel has become our favorite and coolest launcher accessory.