16"/50 naval gun ignition cartridge?


Can anyone tell me about the ignition cartridge used in the U.S. Navy’s 16"/50 battleship guns? I only know it could be percussion or electric primed. Were there two types, or one type that could function both ways?

I assume this cartridge to be similar to the one’s used by field artillery that look like a .45/70 cartridge case, only MUCH bigger.

Anyone collect this specialty that can show artillery igniters from various countries and eras?



AKMS, the 16-inch sea coast material used the MK15 primer (1942 manual). This one is also used in the 8-inch railway gun and probably others.


Here the MK15 MOD3:

There are several others for US large caliber artillery.



Most landlubbers are surprised when they learn that the big 16" naval guns take the tiny lock-combination primer. It functions either electric or percussion. Each powder bag has an ignition pad of black powder sewn to the end and so the primer only has to ignite the BP which in turn ignites the main propelling charge.

Likewise, the fuze on the big projectiles is similar to those used on all other lesser guns. It is small when compared with the large projectile body. But again, the purpose of the fuze is to ignite an Aux Det fuze which in turn ignites the main bursting charge.



Interestng. I never would have guessed that little ignition cartridge could end up setting-off 660 lbs. of powder in a 16" gun.

Slightly off-topic, but how did they clean the barrels of those big guns? After firing all those charges with black powder in them in a salt air environment, cleaning must have surely been required…




The bores were cleaned like any other gun - only bigger. A jointed cleaning rod, a bristle brush, wool mops, diesel oil & grease. Oh yeah, and a bunch of unhappy Gunners Mates and GM strikers.



And, possibly, for the Enginemen (happier than the GM’s) who provided that diesel fuel used to help in swabbing out those big bores, a bit more “entertainment” at the next port of call…?? !!


Of course! We had to keep our EN shipmates happy. A cold brew with just a touch of diesel fuel for flavor. ;)


Hello Everybody!
Yes, cleaning a 16" gun can be a chore. We used an original bore brush that was stored beneath the gun crew’s platform in the center gun room. Forward of the turret were port and starboard capstans for taking a strain on mooring lines. We used those to assist in pulling the very large brush through the bore. The bore obstruction plug gage was kept in the booth in a rack on the bulkhead. It was a large, heavy and somewhat clumsy affair that was used for pre and post fire checks. We covered the teak deck with an acre of tarps to prevent CLP from damaging the wood. Cheers!


Hey! Another GM shipmate on board. That gives us three GMs, an EN, an FT, and a Torpedoman. We’ll soon have them all outnumbered and can verify each other’s sea stories.



Back during my sea duty days (1990-1991), we Marines had to teach the sailors how to operate and maintain the ship’s M-2 .50 caliber machineguns used for the small boat watches… I guess the GMG’s were too busy keeping the old 3"/50 mounts in working order…or off drinking coffee somewhere. My general quarters station was in the forward ready-magazine as an ammunition handler. I volunteered (who would’nt want to handle large ammunition all the time?) the sailors were assigned, like it or not. They stuck us with this one poor kid who had a medical condition that caused his hands to spasm in the open position, at randon, without warning. Who was the genius who assigned him to handle live ammunition? During drills and a real GQ alarm at oh-dark-thirty, we told the kid to go sit in the corner of the magazine and not move from that spot! I was amazed that all of the 3" ammunition we had was from the 1950’s, with inspection dates in the 1970’s. Most were steel cased, but some were brass. I wanted to cry when we threw a bunch of that beautiful brass overboard… Marines don’t cry, but cartridge collectors do!



My first ship had 2 enclosed 3"/50s. I sent 2 brass cases home in a Mk 58 smoke float container. We expended just a scant handful of brass cased ammo. All the rest was steel cased. I recall an interesting exercise when we put a smoke float out for a target and were instructed to shoot VT-FRAG ammo. For some reason, the projectiles never made it to the target! On the Missouri, we used a lot of old 16" projectiles and propellant. The 2700 pound APs were made around 1940 and had new base detonating fuses installed. I can’t recall anything peculiar about the HCs. We did have some brand new 1900 pounders with hundreds of little winged grenades in them. A lot of the powder was from the early 50s. We used some vintage 8" bags for reverse slope firing.