Hi all, I picked up an old Hopkins and Allen falling block 12ga shotgun action. The thought here is to make a heavy slug gun out of it. I rockwell tested the action and it is 65 on the B scale. Seems pretty soft. I've calculated yield and shear based on hot rolled 1020 and came up with a max chamber pressure of 17ksi with 100% saftey factor. I couldn't find a reference on how to calculate shear in threads though. 1.1" OD x 1.8" shank. I'm guessing half the peak of the thread so OD x PI x 1.8/2?? for shear area? Anyway, I'd like to heat treat the action to increase the strength, but I don't know exactly what kind of steel it's made out of that's why I went with 1020. Is there anyway to findout what it's made of?

Thoughts?

Most larger heat treating facilities have metallurgical services available. they will shave off a tiny piece of steel from your action and chemically analyze it for you.

Blue

Lar,

Send me a small piece of the steel and I'll shoot it in the electron microscope and return a printout of the chemical makeup of the steel.

Nitroman, email sent

lar45, What force in the action would act to shear the threads, other than the "drag" of the bullet?,
Take Care!