120 MM Cannon Not BP, Don't know really what makes it go BOOM

[Marine Dad]

Thought everyone might like to see this, from our replicas of the historic, to real thing used today.
If I have done wrong please let me know.

Some on here may recognize this bore.
Not Black Powder or Pyrodex, but a BFG anyway you look at it.

My Son took this pic back in 2008 at Fort Knox KY.

[1Southpaw]

Breech loader , Brass cartridge , primer fired . I have shoved a lot of rounds up a 105 as a loader . also had experience with 155 . !55 one had to ram projectile in to the lands  then load the brass with powder charge . the 105 brass and projectile were loaded together . The powder charges were connected bags with string between powder bags. when a fire comand was called in the correct number of powder pags were pilled from the brass, the projectile put back in the brass and powder bag string ripped off , powder bag in to pit , round in to chamber.

[Marine Dad]

Thanks,
My Son never really explained it to me.

By the way, Son is Lcpl Craig S Smith USMC, currently stationed at Camp KV western Iraq.
Tank Crewman

[brokenpole]

Thanks,
My Son never really explained it to me.

By the way, Son is Lcpl Craig S Smith USMC, currently stationed at Camp KV western Iraq.
Tank Crewman

Please thank him for his service.

[1Southpaw]

I finished up my service as a Tank commander in the Montana National Guard. Better duty than an Artillery man , particularly when it rains   

I thank your son for his service to this country .

side note : the breech on the picture piece looks to be a spring loaded one . One had to be sure to push brass in to place with a closed hand . They would bite a finger pretty hard if caught in the breech. ! 

[cannonmn]

The 120MM main gun on those tanks used a fixed round with combustible cartridge cases.  The "stub case" portion only is steel, about 3 inches long and about 8 inches diameter, weighing about 7 lbs., is all that is ejected after firing one shot, all the rest of the case burns up in the chamber before the breech opens.  I know because my company, Springfield Arsenal, carries the stub cases as an inventory item for collectors-as I recall they are $30. plus shipping.  They make nice ash trays.  We also carry long steel tubes with cam-and-lever type closure plug at one end, whcih are used for shipping each round.  They weigh about 20 lbs. and are very much air and water-tight.  They are in inventory also, $25. plus shipping.

Here's a pic of the primary round the tank carries, along with size and weight.

http://www.aollc.biz/pdf/120mmTankM829.pdf

This IS a black powder-related question, because the foot-long primer extension near the base of the cartridge case, uses a couple of ounces of black powder to get the main charge ignited as quickly as possible.

[Double D]

I let this run because of the the Watervliet Arsenal link.

[dan610324]

is black powder often used as priming powder in modern artillery ammunition ??
or is it just in a few ??
just wondering why they dont use any modern nc powder as priming powder

[ratpatrol]

In the early 60's Hodgen powder got in truck load of surplus 8 inch base charge cannon bages, these had a pad on each end and a cord down the center that had about a pound of pea size black powder in them. they sold them for 15 cents each. The smokeless had been taken out of the bages.  This is what started me into Big bore cannons, beer can size.  Two foot of thick wall seemless tubeing , a can full of concrete, and a lot of memeries.  The same powder know is going for $7.50 a lb.

[Cat Whisperer]

is black powder often used as priming powder in modern artillery ammunition ??
or is it just in a few ??
just wondering why they dont use any modern nc powder as priming powder

In separate-loading artillary pieces, the projo is rammed into the rifling and then the 'cut' powder bags (cut = only charges that are needed are included) are inserted, the breech closed and then primed.  On the base of the largest bag (charge 1) there is a red end under which is a layer of blackpowder - used to 'catch' the sparks from the primer.  (155mm, 175mm and 8" in our inventory, where the 105mm is loaded (powder charges cut and placed into the brass case) with projo and brass case at the same time.  Modern powder is coated with graphite - it takes a strong force (brissance) to shatter the grains and ignite it, where black is much more reliably ignited.