Typical projectile nomenclature


#1

Found this tidbit in TM 30-240, SOVIET PROJECTILE IDENTIFICATION GUIDE, dated Feb. 1953. While dedicated to the larger caliber items, this particular page could be considered generic in its approach to the topic. Applicable to SAA in many respects. Had never given much thought to the “areas” that are pertinent in identifying projectiles.


#2

Cool drawing, makes it clear what is what.


#3

Rick,

Interesting drawing and thanks for posting it. Goes to show the detail of an artillery projectile often taken for granted. Hope you don’t get into any trouble for distributing “RESTRICTED Security Information”. This Cold War thing could get “hot” at any time…

If Boris and Natasha knew you know this, there could be consequences.

Dave


#4

I’m more worried about “Barry”.


#5

“Bourrelet” is a new term to me. Is that term usually only used to describe that feature on artillery projectiles?


#6

DK

Those would generally be the only projectiles with that “feature”. It may be used with mortar rounds, as well. Some of them have that ridge before the ogive. Keeps ‘em from rattlin’ around in the tube too much, as well as part of the gas check design. More so the latter, I’d guess. Haven’t ever seen the same type drawing for mortars. Never seen one for projos 'til today.


#7

Bourrelet means rim.
Therefore a rimmed ctge is called a “cartouche à bourrelet” in French.

jp


#8

Many long range bullets have a feature that serves the same purpose as a bourrelet on an artillery projectile. They are commonly called bore-rider bullets.

Not all artillery projectiles have a bourrelet. Some have none whereas some may have two or more.

And not all artillery projectiles have a screw-in adapter.

Ray


#9

The artillery shells without a bourrelet have to use the cylindrical body as a “bore rider” surface. Making such a long surface with a more precise diameter, and surface finish, is more difficult and therefore slower and more expensive. Hence the narrow bourrelet with a clearance diameter behind it.

Also, without a bourrelet then any markings stamped into the metal body may raise a burr on the bore-riding surface - not good for the gun or accuracy.

gravelbelly


#10

One of the more common projectiles without a bourrelet is the 40mm Bofors. They were made and fired by the gazillions without any apparant problems.

Ray


#11

Can anyone tell me whats the purpose of the cannelure below the driving band. Or was it just put there so they could show a cannelure for illustration purposes?


#12

Vince,

I would think that would allow for crimping the case to the projectile in fixed ammunition applications if desired. I’m not sure if the cannelure is always present on larger, separately loaded rounds.

Dave


#13

Vince

What Dave said. A cannelure is not usually present on semi-fixed or seperate loading projectiles. You will find such a groove on the more common fixed ammunition such as the 3"/50. Some may have multiple cannelures. I think that particular drawing was intended to show all the features of a projectile even though some of them are not present on all.

On some semi-fixed or seperate loading projectiles you may find a small cannelure below the rotating band, especially if it’s of the design with a pronounced gas-sealing flare at the bottom of the band. I believe that it is there to provide a place for the rotating band material that is displaced by the rifling but don’t hold me to that explanation because I’m not sure. It’s just a SWAG on my part. Or maybe it was something that I used to know but have forgotten.

Ray


#14

[quote=“RayMeketa”]One of the more common projectiles without a bourrelet is the 40mm Bofors. They were made and fired by the gazillions without any apparant problems.

Ray[/quote]

Ray, I agree but the Bofors projectile is small and with a limited parallel length, relatively easy to machine true. Try to turn a large shell and hold that accuracy over a much larger area. Besides, the large expanse of accurate cylindrical surface is unnecessary, just skim a clearance and leave a bourrelet.

gravelbelly


#15

Surely though any shell of cast iron construction with a driving band was intended to ride on the rifling. There is no other way it could get down the barrel. Artillery barrels generally have a “microgroove” barrel with a large number of shallow grooves that only engage the driving band. Everything else is down to a tolerance fit although how tight or accurate those tolerances were under battle field conditions is probably subject for another debate.


#16

The paint on a projectile probably has a greater thickness than the tolerance allowed when turning the body. But, the tolerances were not as much as you might think, even considering wartime production.

I’ll confess that I’m not quite sure what we are arguing (discussing) here?

Ray


#17

[quote=“RayMeketa”]One of the more common projectiles without a bourrelet is the 40mm Bofors. They were made and fired by the gazillions without any apparant problems.

Ray[/quote]

… But the 40/70 Bofors does have a bourrelet (at least in Spain).

The projectile diameter is 39,9 mm at the bourrelet and 39,2 mm at the body.