Stability of 16" projectiles

[Chogy]

VERY interesting. I had no idea nitrocellulose had been abandoned as a major constituent for large-bore naval cannon. Thank you. :)

[tlturbo]

Rumrunner - If you are serious about wanting a 16" projectile, e-mail me as I know where there are some for sale (HC not AP).

It would be interesting to know (probably hard to find out) when they stopped LOADING complete projectiles. I know Crane in Indiana was still making the shells in 1969 as that is the date stamped on the driving band of my shell (Mk 14 HC).

I STILL need to stencil the shell someday.

[Gun Grape]

Nitro Cellulous is no long used.

After WWII SPD (Smokeless Powder Diphenylamine) a cooler burning propellant was introduced to prolong the barrel life. And this was even furthered before they left service.;)

Have to correct you here.

The Propellant is Nitro Cellulous.

What causes it to burn cooler is the various types of perforations, Such as 5 holes, 7 holes or 1 hole through the middle of the granule. Length and diameter of the granule also plays a factor and placing various different propellants in layers.

There are also various additives such as wax that cause it to burn cooler. Other things may be added such as lead foil around the inside of the powder bag to reduce coppering.

In addition you can have a silk powder bag or a polyethylene bag. The poly bag helps reduce wear.

Throw in a little Potassium Nitrate or Potassium Sulfate on top and/or between bags to reduce flash . A little black powder/Clean Burning Igniter to set the whole thing off and you have a complete propellant charge

SPD is the propellant used during WW2. During the 60s they added titanium dioxide and wax (Swedish additive) to the mix

[Gun Grape]

As for the original question concerning shelf life of the rounds.

My question is how long can a 16" projectile be stored before the explosive part becomes unstable or just plain no good?

Answer may vary depending on the result you want. The shelf life of Comp B and TNT is approx 40 years.

However that doesn't mean that the projectile will not go boom. Shelf life for military explosives are set where the explosive has degraded to the point of being 20% less effective than when new. Its still going to go boom but you wont get the full effects.

As far as unstable, mil explosives are pretty insensitive, as long as they have been stored properly, the chances of them being unstable are slim.

[Gun Grape]

only real problem with storage is heat, bursting charge can melt and re solidify to one side out of ballance projectile.

in my experience and time have not seen or heard of any other problems other than above with un fyused projectiles.

If the bursting charge/HE melts and then re solidifies the round will most likely detonate on firing. If it doesn't do it when the round was moved.

TNT/Comp B type explosives are crystalline in nature. Once it it taken out of its solid state it will harden as a powder (Not bond back into a solid block). Friction of the powder crystals during movement or from the shock of firing will cause a big boom.

[Dreadnought]

SPD is the propellant used during WW2. During the 60s they added titanium dioxide and wax (Swedish additive) to the mix.

Thanks Gunny, got it backwards.

Nitro Cellulose Cordite smokless.

Would Delta 846 be considered the same?

I have the projectile bursting powder as RDX tnt picric acid #26 Bursting lydite.

[USSWisconsin]

From some of my readng I have heard that they added a polyurethane sleeve to the powder bags in the 1980's which effectively coated the bore via a CVD like process (Chemical Vapor Deposition) to reduce bore wear to almost insignificant levels (with the other improvements metioned above). CVD is a deposition process used in building computer chips, and may have helped to inspire this improvement.

[Dreadnought]

From some of my readng I have heard that they added a polyurethane sleeve to the powder bags in the 1980's which effectively coated the bore via a CVD like process (Chemical Vapor Deposition) to reduce bore wear to almost insignificant levels (with the other improvements metioned above). CVD is a deposition process used in building computer chips, and may have helped to inspire this improvement.

Yes, they did add the sleeve .It increased the diameter of the powder bags very slightly but worked wonders for wear factors.

[USSWisconsin]

SPD is the propellant used during WW2. During the 60s they added titanium dioxide and wax (Swedish additive) to the mix.

Thanks Gunny, got it backwards.

Nitro Cellulose Cordite smokless.

Would Delta 846 be considered the same?

I have the projectile bursting powder as RDX tnt picric acid #26 Bursting lydite.

Is RDX used as a bursting charge in battleship projectiles?

[Gun Grape]

Don't have my ammo handbook on hand but the main fillings are either TNT or Comp B. in HE/HC rounds for the 16" (or most any other artillery)

Which is what I'm assuming you mean.

RDX is sometimes used in the fuze to "Get things started":))

[Dreadnought]

Don't have my ammo handbook on hand but the main fillings are either TNT or Comp B. in HE/HC rounds for the 16" (or most any other artillery)

Which is what I'm assuming you mean.

RDX is sometimes used in the fuze to "Get things started":))

*Understood, thanks Gunny. You do realize this will eventually lead to gunfire preparation sheets and comparisons between land artilliary and sea platform gunnery and their differences in the near future right?:))