4.65 inch - 12 pdr projectiles

[KerryG]

Tracking a Confederate gun with a bore dimension of 4.65 inches.  So...the projectile would probably be 4.62 or 4.63.  Anyone found any round like that, that maybe you "thought" was for a 4.62 gun...but was actually slightly larger? Probably a long shot, due to effect of corrosion...but thought I would ask.

[CarlS]

I'm not aware of one.  Sounds a bit like a worn out gun.

[KerryG]

From what I've found (so far)...these 4.62.Siege guns were iron guns.  "Worn out" has been been suggested as a reason...and also gun "casting defect" that necessitated re-boring has been suggested.  I'm thinking the later, because there is an order for rounds for a "12 pdr Rifle Siege gun"...and it's less than a year after most of the Confederate guns were cast.  At any rate, 300 "bolts" for the gun were made and sent..."somewhere".  Just wondering if anyone had turned up any of these slightly larger than normal "4.62" rounds anywhere.

[redbob]

James made a 4.62" round for a "Heavy" 12 pounder, if these tubes wore could these have been the rounds for them?

[KerryG]

The order for the 4.65 rounds was made to a "Deep South" foundry...that was pretty much making nothing but Reads at the time of the order.

[KerryG]

Dr. Larry Babits had an excellent article on the Gibbon & Andrews 4.62 rifle in the latest issue of Artilleryman Magazine.  He mentioned a formula used to calculate a projectile's "safe weight" for a gun (rifled in this case).  Does anyone know that specific formula.  I've looked in the Confederate ordnance manual but haven't found it.  Thanks for any help on that.

[CarlS]

Interesting question.  I would guess the formula would have the variables of the the breech thickness along with desired bore diameter to give the weight.  For example, an Ordnance gun couldn't consistently handle as heavy a projectile as a Parrott gun.  Quality of metal and cooling practices affected cannon strength as well.

[emike123]

Kerry,

Your partner in this research endeavor is at my house measuring and photographing away for the second day.  He thinks he has solved this mystery.  I will leave the information to the two of you to publish.

Thanks for asking this provocative question.  What seems like a nit at first blush, usually has a very good reason.

[KerryG]

Thanks Mike for all your help with this!