Letter: Tumbling Loaded Ammo Does Not Lead to Ka-booms

Regarding the “Odds ‘n Sods” column from March 22: This is an “old husband’s” tale. Tumbling loaded ammo will not make it prone to detonation. Geoff Beneze, formerly of Dillon Precision, tumbled loaded rifle rounds (ball, flake, and extruded powders) in a vibratory tumbler for six months continuously and had zero issues with any of it. His emails are archived on the Yahoo handloading group. Unfortunately, you have to be a member of the group to read the archives, but here are a couple of the relevant emails I’ve saved:

“First off, I would strongly urge that are so inclined NOT to accept my experiments and run with your own ignorance and prejudices. It just makes life a lot easier.

“There’s no need to send it to MythBusters; the work has already been done, several years ago and then repeated again this last fall. Boy, I’ve been busting such shooting myths YEARS before anyone thought to do a TV show.

“You’ll not get email or public acknowledgement that the factories do so. In fact, if you talk to “head office”, PR, or any of the corporate attorneys, you’ll be blasted off your seat for so suggesting. This is either a deliberate case of front office denial, or simple ignorance of the process by the “higher ups.”

“When you take the time to filter down and talk to the engineers, EVERY ONE of them admits that they do so. Moreover, this was confirmed for me by a family member who worked (now deceased) for Olin.

“My procedure was (two times now) to tumble representative samples of each type of powder, ball, flake, and extruded. I used different powders in each experiment, IIRC.

“These samples were tumbled in a Dillon vibratory tumbler for six months 24/7. (The tumbler did this twice.) Microscope photos were taken before and after.

“In the initial experiment, a strain gauge peak pressure meter was used. In the second, a more advanced, full pressure curve (also stress sensor) unit was employed. I haven’t yet completed writing up the second experiment, but the results were fundamentally identical to the first set. No statistical variance from the control powders.

“As to rounds going off in your tumbler, you need to read Hatcher’s Notebook about the forces needed to detonate primers. Then you need to do some calculations as to how much force a round could (falling) generate in a standard sized tumbler, let alone the cement mixer sizes that the factories use.

“Go ahead and do the math; I’ve already done it several dozen times.

“HOWEVER, when you have one blow, as you seem so certain will occur, save the setup and let me know. I’ll want to get photos of that historic event.” – S.B.

HJL Replies: Which begs the question: “Why are commercially-produced rounds going Ka-Boom then?”

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