Has anybody seen any recent data compareing the brisance of different primers ?

I'll bet not many even know what brisance is! I've NEVER seen any data on it anywhere, ever. Where have YOU ever seen any data? I'd like to see it. There have been many articles showing pictures of the flash of various primers and some other and similar comparisons but the only place I've ever seen brisance discussed is in some very old NRA publications and they didn't have any comparisons.

Bob338

Is this the NRA that used to have neat experimental projects and tests and shooting and reloading artcles.
Oh yeah, those days are LONG gone.

This was made very apparent to me when I forund some 60s era ARs.

Todays gunzine writers tell us of the latest puffinsmoker loudenboomer.

Luckily there is AR and other sites like this to learn and shre real information!

Kepp going Seafire, you just about have me covered!

Guess I am going to have to go out and buy a keg of Blue Dot to cover all my new loads Seafire has brought up and the trusty old 429421 load too!

If I can just get it to perform accurately in the 222!

Seafire . . . you need a good 222 and 45-70!

I'm not sure how recent this is...
http://www.castingstuff.com/primer_testing_reference.htm

Here is all I have found so far
http://www.leverguns.com/articles/johnk/primertest.htm
I am at present more interested in small rifle and pistol primers .

You mean no one's gonna tell us what "brisance" means????

Searching with Google:



Brisance



The characteristic in an explosive of brusqueness or shattering power. The more brisant an explosive, the more rapidly it detonates and the greater its relative power.



Brisance



In addition to strength, explosives display a second characteristic, which is their shattering effect or brisance (from the French meaning to "break"), which is distinguished form their total work capacity. This characteristic is of practical importance in determining the effectiveness of an explosion in fragmenting shells, bomb casings, grenades, and the like. The rapidity with which an explosive reaches its peak pressure is a measure of its brisance. Brisance values are primarily employed in France and the Soviet Union.









The rapidity with which an explosive



This article is concerned solely with chemical explosives. There are many other varieties of more exotic explosive material, such as nuclear explosives and antimatter, and other methods of producing explosions, such as abrupt heating with a high-intensity laser or electrical arc.



Any explosive material has the following characteristics:



* It is chemically or otherwise energetically unstable.

* The initiation produces a sudden expansion of the material accompanied by large changes in pressure (and typically also a flash or loud noise) which is called the explosion.





..... Click the link for more information. develops its maximum pressure



Pressure p (lower case) is a measure of force per unit area.



The SI unit for pressure is the pascal (Pa), equal to one newton per square metre (N�m-2 or kg�s-2�m-1). A convenient unit for atmospheric air pressure is the hectopascal (hPa), which gives the same number as the older millibar (mbar). Non-SI measures (still in use in some parts of the world) include the pound-force per square inch (PSI) and the bar. In the United States air pressure is still measured in inches of mercury (as in the mercury barometer).

..... Click the link for more information.

is a measure of the quality known as brisance.



A brisant explosive is one in which the maximum pressure is attained so rapidly that a shock wave In fluid dynamics, a shock wave is a strong pressure wave produced by explosions or other phenomena that create violent changes in pressure. See Rankine-Hugoniot equation.



In compressible fluids such as air, disturbances such as pressure changes caused by a solid object moving through the medium propagate through the fluid as pressure waves traveling at the speed of sound. When the cause of the disturbance is moving slowly relative to the speed of sound, the pressure wave enables the fluid to redistribute itself to accommodate the disturbance, and the fluid behaves similarly to an incompressible fluid.

..... Click the link for more information.

is formed, and the net effect is to shatter material surrounding or in contact with it. Thus brisance is a measure of the shattering ability of an explosive.



This characteristic is of practical importance in determining the effectiveness of an explosion in fragmenting shells, bomb casings, grenades, and the like.



One of the most brisant conventional explosives is Cyclotrimethylene trinitramine Cyclotrimethylene trinitramine is an explosive material widely used by the military. Commonly called RDX (Royal Demolition eXplosive or incorrectly Research Department Explosive), but also cyclonite, or hexogen. Its formal name is sometimes rendered as Cyclotrimethylenetrinitramine.



In its pure synthesised state it is a white crystalline solid. As an explosive it is usually used in mixtures with other explosives and plasticizers or desensitizers. It is stable in storage and is considered the most powerful and brisant of the military high explosives.

..... Click the link for more information.

.







BRISANCE

The ability of an explosive to shatter the medium which confines it; the shattering effect shown by an explosive.





Brisance: The characteristic in an explosive of brusqueness or shattering power. The more brisant an explosive, the more rapidly it detonates and the greater its relative power. Usually applied to primer compounds.

Thank U Clark! roger

To expand a bit further on the great stuff supplied by Clark, the term is misused and misunderstood when applied to primers. The primer is expected to ignite the powder, not to shatter it.

In the laboratory, brisance is determined by detonating a specified quantity of explosive, usually about 6.16 grains, in a bed of special sand. The degree to which the special grains are shattered, determines the brisance. It isn't necessarily indicative of the energy or heat liberated by the explosion but upon the suddenness with which the products of the explosion are released.

The brisance is also related to detonation velocity. RDX has a detonation velocity of about 7800 Meters per second. This is about the ball park of Nitroglycerin. Amonium Nitrate is about 3000 meters per second, but generates a large lifting force and it is cheap so it is used in Rock quarries and other uses where earth is to be moved.

RDX is mixed with a plasticiser and some other stuff to make C4. It is less sensitive and easier to use when that is done. Also reduces the detonation velocity a small amount.

All explosives (I know anything about) have a shock value that will cause them to detonate. This is tested by droping a one kilogram weight on a sample under controlled conditions. All explosives have a temperature that will cause them to detonate.

A small amount of any explosive in contact with your finger or other body parts will generally clean it right off if it detonates.

Wow! I'm over 60 and all I ever knew was some burnt hotter than others. Thx

"Brisance" is not a "good " thing in a primer. The term was picked up by Gun Writers
trying to convince the reader that they were "technical" people. As most Gun Writers
are illiterate technically, others picked up on it. I thought it had died out in articles,
but I wouldn't really know as I have given up on Gun magazines.
Good luck1

The tests referenced on the www.castingstuff.com web site were done in the last year.