Hybrid Barrel Explosion

[MrCrowley]

I just bought two barrels today. One 7ft long copper, 1/2 pipe, and one 5ft galvanized steel 1/2. They both have different inner diameters, for the two ammo types I will use.

Wait a sec, you're using 1/2" diameter barrels on a hybrid with a 2" union? I'd suggest building a different cannon for barrels that size and use this hybrid as a big-bore launcher.

[whoa044]

By two ammo types, I meant two small bore ammo types. I'm not worried about any of the larger barrels failing upon firing. I plan on using the compound rounds by UltimateSpudGun as well. My goal for those would be at least 900 fps.

You should use the yield strength, not the failure one. You also need to add in a safety factor. Finally, the seam on that pipe and the galv (galvanising is done hot, and tends to soften the metal) will drop the strength by a lot.

It's not galvanized, and it's forged steel. The company does not provide any info on the type of steel used, but I was assuming it was at least 40,000psi tensile strength.