I did an experiment yesterday that leads me to believe the WLP primers have twice the energy of WSP primers.

Is there a table anywhere that has a grains of powder equivalent of different primers?

RANKED IN ORDER OF POWER
Gold Metal Match 215M
Federal 215
CCI BR2
CCI 250
Winchester WLRM
Winchester WLR
CCI 200
Rem 9-1/2 LR
Winchester WLP
CCI 300
Federal 150
Federal Match GM150M

Of course this changes with each and every batch or lot of primers...

What kind of test bed did you use on small vs large primers that let you draw a valid conclusion?

By how far they pushed a lead bullet down an unlubed barrel...

[QUOTE] [/QBy how far they pushed a lead bullet down an unlubed barrel...

UOTE]
I still fail to see how this allows you to compare the energy of the two. If you fire a lead bullet in a 38 spcl with a small pistol primer what do you fire the large primer in that uses the same bullet wgt and has the same chamber volume for the primer to build pressure? also the bearing surface of the different bullets would cause the pressures to vary. I don`t see how a valid test can be done with out some pretty fancy equipment.

Sounds like a useful test for determining whether one primer is more powerful than another.

But, just because one primer pushed a bullet twice as far as another primer doesn't necessarily mean it is twice as powerful.

The weaker of the two primers may have expended most all of it's energy pushing the bullet to overcome the resistance to engraving by the barrel lands. Once the bullets are engraved, I suspect they push more easily, though. So, perhaps the stronger primer just had somewhat more power (total applied energy) rather double the power? It not only overcame the engraving, but pushed the then more easily moved bullet farther down the bore.

A good experiment, but complex enough forces/resistance involved to not absolutely count on linear measurement representing linear increases in power?

Or, maybe it does mean twice the power? A question which makes me wish we had an interactive interior ballistics website at which to ask things like this.

AC

I was noticing how loud the S&W 25-2 [45 acp] was with a just a primer vs a Colt Pocket postitive [32 S&W long]

They pushing a .315" and .457" lead ball respectively about 300 fps with very high expansion ratio [the primers showed pressure signs with no powder].

The noise being proportional to the supersonic gas ball, and the 45 having a much higher volume barrel, and the 45 being much louder, made me notice.

So the test was really a measurement of gas volume.

You guys are really beautiful!

First of all, the same bullet was not used over and over......geesh!

Secondly, all large primers were fired in a single shot T/C .44 Magnum, and the same case was used for each firing. All small primers were fired in a single shot T/C in .357 Magnum, and the same case was used for each firing!

I doubt very seriously that ANY of you have taken the time to try any experimentation, but you sure are able to criticize!



[ 04-30-2003, 06:16: Message edited by: ricciardelli ]

Steve,

While there are purposes to having powerful primers, does the "power" of the primer have a direct correlation to the heat of the primer flame and thus to the primer's ability to ignite powder? Could you explain the whys and wherefores? Thanks.

Steve,
I actually think that was a pretty novel way of testing primer "power". Bob Jensen about 25 years back built a rig to use primers to fire BB's and recorded their velocity as a measure of their force. He found that the mildest primers did not necessarily correlate to the most accurate for his application - Long Range Highpower Rifle.

Clark, did your experiment replicate Jensen's in concept?

Hobie, there are other factors that go into primers. One such would be brissance - how much "spark" it puts out to ignite the powder. There's been some pretty neat experiments done in this area by Creighton Audette as well.

I was once working up to ~60% overload in 9mm when the primer pierced.

I switched to the thicker WSPM magnum primer, continued working up without reducing, and the case head blew off without me getting the case bulge and then hole in the case warning.
Afterwards, I guessed that the switch to the magnum primer was the equivalent of at least .7 gr of AA#5 from that expensive, painful, and embarrassing test.

So today, when I was shooting lead balls around the basement with primer power, I became suspicious that the large primer was much much more powerful than the small primer.

A successful engineer once told me, "The energy of a gas is the mass times the temperature, but that is not same as the available energy." He would probably be disgusted with how I phrased some things here, but what I would really like is powder equivalence. If I could shoot a small primer in a 45, I could do that.

[ 04-30-2003, 09:51: Message edited by: Clark ]