6 thoughts on “Battleships, again”

  1. I wish I had the software to draw stuff like that! Perhaps we could finally explain how to set headspace and timing on a .50 cal so that even Gomer could handle it.

    1. Headspace is easy to understand and explain.

      But here I am 20 odd years after my intro to the Ma Deuce, and I’m still a little fuzzy on timing. I mean, I can SET it, but not sure about what it is…

  2. The barrel threads into the barrel extension (inside the reciever) which establishes a fixed distance between barrel and bolt-face. This is headspace. When recoil moves the barrel, both the barrel and barrel extension move together. The bolt moves back and forth on grooves within the barrel extension (again, inside the receiver). On the front of the bolt is a T-slot. When a round is fired, the bolt recoils to the rear and the extractor pulls a new round off the feed tray and drops it into the T-slot on the front of the bolt (while the expended case drops out the bottom of the T-slot). As the bolt travels forward, the round slides down the T-slot and enters the chamber. As the round seats in the chamber, the bolt, barrel extension and barrel are all in battery and the firing pin releases and fires the chambered round. Because the round is in the T-slot from the time that it is pulled out of a link on the feed tray and drops into the T-slot, if the timing is early, the firing pin will release too early and the round would fire before being fully seated in the chamber. This could cause the barrel extension to crack, and likely blow the feed-tray open (suddenly your gun is down). If timing is too late, your gun fires sluggish or not at all. Both of these conditions =Bad. Nutshell: setting timing ensures that your firing pin releases when all parts of the firing mechanism are in battery, so it doesn’t break, and it fires at the correct cyclic rate.

  3. Ahh Battleships. Just something about vessels designed to fire and withstand hits from 1000 + lb shells that has always fascinated me.

Comments are closed.