I recently acquired a 6.4" Parrott Bolt (wide bottle top) that was described as "mint" in reply to my initial inquiry. Upon receipt and close examination, I observed what appeared to be a lathe dimple or sprue mark with file marks on the top of the bolt. I was preparing to clean up the bolt and removed some surface rust on the top center. This revealed a hole filled with what appeared to be bondo. Thinking the worst, a huge casting void dummied up with filler and hidden, I started chipping the bondo away. This revealed a perfectly centered, 1/2" diameter hole, drilled 3 inches deep into the bolt. The hole appears to have been there for a very long time; the bondo, obviously more recent.
I have no idea what this hole is or what purpose it might have served. If you look at pages 293 and 294 of Mr. Bell's book on heavy ordnance, the bolts depicted there show circular marks on the top center that are the exact placement and size of the hole in my bolt. Several suggestions have been made as to why this hole is present:
-Attachment point for counter weight
-Drilled by some unknowing person who thought it needed deactivating
-Anchor point for display of stacked projectiles
-Drilled for proof of solid, non-expolsive status
-Drill running to create lathe dimple and the machinist went on a coffee break?
Other than this hole, the bolt is in fact near mint. I'm attaching a photo of the hole and would appreciate any thoughts or ideas that you experts may have on what this is. Thanks.
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