Thanks for your understanding of seacoast gun fire, Double D. You wrote: "I suspect if you do the math for the amount of elevation/range change available in a full travel of the elevation screw with in one notch. you will find the effective range of the gun is within two or three notches. I would also suggest that in any one engagement no more than one or two notch changes were made, that most adjustments were made with elevator." This is exactly correct. Most fire missions in a coastal fort or battery were carried out at known distances, and most of the time at the same distance for multiple shots.
Several of these banded and rifled guns were located at Fort Moultrie and in nearby batteries defending Charleston Harbor. They were in Battery Marion, 200 yards west of Moultrie and battery Bee, about 300 yards west of Marion. The one in Battery Bee in 1863 was originally a 10" Seacoast Columbiad M1844. Due to battle damage from two separate hits, it had only one trunnion and scars near the muzzle. The Eason Bros. double banded it with wrought iron, rifled it for 10" Harding projectiles and re-trunnioned it with a unique solid bronze trunnion band. On one particular occasion this big rifle fired five 231 pound bolts at 1,438 yards using 15 pounds of powder at 3.25 degrees elevation. This was most likely a Monitor sinking fire mission, as they hung out at 1,100 to 1,500 yards to bombard the forts, Sumter and Moultrie and batteries Wagner and Greg on Morris Island. Also the gun was firing solid bolts for penetration, not shells.
For firing shells at long range (anything over a mile) the artillerymen would switch to shells for area targets like troops in the open. This would be completely different scenario. Such an opportunity would present itself on the morning of September
7, 1863. The Confederates finally abandoned Battery Wagner and nearby Battery Greg on the night of Sep. 6-7, after being incessantly bombarded by Gilmore's siege batteries and the Federal fleet for months and months. The heavy guns of the Sullivan's Island batteries gave the Federal troops a hot welcome as they swarmed over their new territory. Even the treble banded Brooke in Battery Marion gave them a Baker's dozen. Most heavy guns firing shells, which were more fragile than bolts, would fire at a much higher elevation, say 15 to 25 degrees with reduced charges. The ten inch rifled gun might use 7 or 8 pounds of large grain powder instead of 15. The greater range of approx. 1.6 miles would be accomplished with much greater elevation requiring a completely different section of the ratchet track near the top.
Tracy