Just that any real differance between them? Mb

Mostly in the price I think.

None with respect to flame, heat, duration of flame, etc. It’s all the same “recipe”. The Federal Match primers are only more consistently loaded by employees wiping the priming compound into the primer cup. Some are better than others in that respect . So, in effect, the primer won’t be any hotter, cooler, whatever. The flame WILL be more consistent in comparison to the next primer down the line.

Believe it or not Remington 9 1/2's are the hottest out of standard primers tests by German Salazer. The tests are just standard Large and small primers, but Rem 9 1/2 runs the best.

https://www.6mmbr.com/primerpix.html

215 mags ? Apples and apples.... Match mag's ?? how much do they cost, to even want to try them? The only way to know is try them. I get better accuracy with a mag primer with slow burning or heavy charges in standard length cartridges. I would say Rem mags, would be good, but it's what's available. I was able to get CCI 250's the other day, but I have a brick of 9 1/2 M too.

Thanks godogs57 that's what I was looking for. The load in question was for the 7 mm rem mag utilizing the fed 215 with T5010 powder. The data I'm sure was derived before the GM215M was brought out. I have both..mb

consistenly loaded doesn't mean consistently burning. Have you used these primers yourself to see a difference Godogs?

If the priming compound is applied more consistently why wouldn't it burn more consistently?

And everything is absolute, right, or is that what they market ? What ever works in my rifles, is absolute, and I'll market that based on how it works in my rifles.

I can’t tell any difference. I happen to have more GM 215M’s than 215’s; I use what I have.

These days you use what ya got or can get.

I also have some 9 1/2’s and like 215’s, they work.

I’d say one has to be pretty sophisticated and a crack shot to even see a difference, assuming there is one. Guess I’m not quite there.

DF

Only for a few thousand rounds


Per year.

Having trouble following your logic though. Wow….

There have been a bunch of primer tests done over the years by various people. And the results tend to vary, as they usually do, including over time.

The A-Square manual, published in 1996, includes a bunch of tests with various primers in their piezo lab, using the 7mm Remington Magnum, with all other components the same, including one lot of H4831 and 160-grain Sierra GameKings.

In that test, the primer that resulted in the highest pressure (67,600 PSI) was the Winchester LR Magnum, for a velocity of 3045 fps from a 24" barrel. The standard WLR was right behind at 64,400 PSI and 3024 fps.

The others were:
CCI 250: 61,500 PSI/3039 fps
Federal 215: 61,400 PSI/3036 fps
Remington 9-1/2M, 59,300 PSI, 3041 fps
CCI 200, 54,800 PSI, 3011 fps

Many might be surprised by the CCI 250, but CCI changed to a hotter primer mix in the early 1990s, not only in the 250 but the small-rifle 450 Magnum primer. Which was when the LR 250 became the hottest commercially available American LR primer. (Though Federal also eventually produced a 216 Magnum LR primer for use in really large-capacity rounds like the .470 Nitro Express and .416 Rigby--but only used it in their ammo, never selling it to the public. I know this because I happen to have one 100-primer container of 416s....)

I also did some measuring and weighing of various rifle primers a few years ago for an magazine article, which eventually also appeared as Chapter 3 in the first Big Book of Gun Gack, published in 2015.

The only primers that didn't vary even as much as .1 grain in weight were the Federal Match primers. Whether that makes any difference in a particular load is another question, because it partly depends not only on the specific powder, but obviously brass-capacity consistency.

You never answered my question completely though wow!

I have a real hard time believing that a primer can result in 8-10kpsi of pressure difference, and still only have 20-30 fps difference.

We’ll depending on the primer itself, it builds pressure in it self. Don’t know how much you would agree with this Hornady ballistictians explanation… but he goes over about primers.

Whoops.

Was shooting this AM, had two 9 1/2's not go bang. Primer was dented, didn't seem to be a light strike.

So, I don't know. Guess it can happen to any brand.

DF

Mr. Barsness,
I am very interested in your thoughts on this. One of the things I have learned from your writings is to carefully watch the chrono as its velocity readings are directly related to the pressure of the loads.
In this case, it is especially odd that every other aspect of the load except the primer is identical, and piezo-measured pressure varied dramatically with no corresponding variation in velocity.

For example, the WLRM produced 3045 FPS at 67.6K (7.6K over SAAMI max) and the Rem 9 1/2M produced 3041 FPS at 59.3K (typical published max pressure).
4 FPS spread in MY shot strings is cause for celebration. How can that exist with 14% pressure level variance?
I spent a LOT of years in military flight test. Had we encountered results like this something significant in test procedure would have been considered suspect.

How do these results make sense?

Thanks for your thoughts,
Rex

The work done by the expanding gas (which manifests as velocity) may be described as the integral of a certain pressure function. 10kpsi of difference in the pressure function may not affect the total value of the integral a lot if the difference occurs on a small enough portion of the interval of integration.

In engineering terms, the areas under the pressure curves are roughly equal while one has a higher pressure peak.

See, no calculus needed.

So just how do you calculate the area under a curve?

Calculus can certainly be used for the actual calculation, just not needed for a conceptual explanation.

You're lucky I didn't go into how the integrand could be modified quite a bit while having zero effect on the integral as long as the modifications occurred on a set of measure zero.

Don't make me dig out my planimeter...

I haven't seen a magnum rifle primer on the shelf here in Alberta since before Covid. I have asked various store owners and neither have they.