Answering John:
The US Ordnance Department's acceptance of the 3-inch caliber Parrott Rifle happened in February 1864. That date gives us a starting-point for manufacture of projectiles for that caliber of Parrott Rifle.
As the Dickey-&-George 1993 book also says on page 149, an explosive shell version of this bolt exists, whose fuzehole is crafted to accept Mr. Parrott's standard 1.12"-diameter Type One Percussion fuze. In addition to the sabot's 3-wide-grooves rifling, the fuzing confirms the projectile was made specifically for use in a 10-pounder Parrott Rifle.
As page 149 mentions, the bolt's diameter is 2.88-inches. That is wider than the diameter of early-war 10-pounder Parrott projectiles. For example, Bormann-fuzed US Read-Parrot projectiles are 2.84"-diameter. I know from personally measuring many Summer-of-1864 10-pounder Parrott shells that they tend to be 2.87/2.88"-diameter. So, to me, the page 149 bolt's 2.88"-diameter suggests 1864-or-later manufacture.
Carl, what is the diameter of the bolt in your photos in this discussion?
In regard to this lead-saboted bolt:
When Mr. Parrott was developing projectiles for his Parrott Rifle in 1860/61, he discovered that lead sabots could not withstand the sudden additional torque from the "gaining-twist" rifling he preferred. A few of the experimental lead-saboted Parrott projectiles he produced have survived. One is a lead-saboted 2.6"-caliber shell, shown on page 221 in the Dickey-&-George 1993 book. I think a Heavy Caliber lead-saboted Parrott is in West Point's projectile collection. I do not recall whether or not that one is shown in the Kerkis-&-Dickey book on Heavy Artillery projectiles. I should mention, I do not know if its ID at that time as a Parrott projectile is still valid.
The "gaining-twist" rifling in Parrott Rifles is why Hotchkiss projectiles were unsuitable for use in those cannons. However, a few were made, early in the war, as evidenced by having a wood-plug fuzehole. I should mention, it is known with certainty that some wooden-fuzed Hotchkiss shells were converted to use a threaded brass fuze. I believe that was done to some wood-fuzehole "20-pounder" and "30-pounder" Hotchkiss shells.
I hope this information is helpful.
Regards,
Pete
