Primer testing

[BUSTINDOGS]

I have a 300 weatherby that I just started working a load for, I actually found a really good load within 20 rounds. tested it with 2 three shot groups and it looks good. Now I would usually like to test it more but I'm running out of gm215m primers. My local shop has every other primer except a 215. Now when I test the other primers can I keep all other variables the same and just use another primer or should I back off a little. I figure the 215 is pretty hot and anything else will yield less pressure...
Anyone had luck with the WLRM primer in the 300 wby or any other primer for that matter.

I feel like I've spent the last 3 years find suitable replacments for everything

 

[Barrelnut]

Hey Dogs. I think you need to back off at least a gr. and work up. General consensus is the WLRM is stronger than the gm215m. I have verified this in a 7 Rem mag. But there is always the caveat... Strengths can change over lots etc.

There are a lots of primer strength charts/tests on the web. Following is a link to one I have always been fond. Anyway, back off and work up. It's the only way.

http://riflemansjournal.blogspot.com/2009/06/primers-large-rifle-primer-study.html

 

[Mikecr]

+1 barrelnut

 

[BUSTINDOGS]

Thanks nut that was a good read
I'm goin to back off a little and try the WLRM
From the article in the link you posted it seem the weaker primer usally produced the best accuracy and lowest sd and es

 

[firstcoueswas80]

Cci 250

 

[J E Custom]

All primers are different so the recommendation to back off a little is a good one but there are also primers that are very close together and if you are not at max pressure you may be able to switch safely and then "Tweak" the load.

Hear is a primer comparison burn rate chart that might help. It will show the primers that are in the same class.

WARNING : Don't substitute anything that is not in the same class without dropping the powder charge first. It looks like the CCI BR2 is a close match to your 215 M ( Not the 215, They are different)

Primer cross reference chart

J E CUSTOM

 

[BUSTINDOGS]

Sorry J E I will have to disagree with you and say that I would interpret that chart differently. The large rifle magnums and large rifle magnum match would be a closer match than the large rifle BR-2 primer. I have a bunch of the BR-2 primers that I used in my creed moor and currently still use in my 30/06 neither are considered a magnum. but I used the WLRM and the GM215M in my 7mm rem mag.

 

[J E Custom]

Sorry J E I will have to disagree with you and say that I would interpret that chart differently. The large rifle magnums and large rifle magnum match would be a closer match than the large rifle BR-2 primer. I have a bunch of the BR-2 primers that I used in my creed moor and currently still use in my 30/06 neither are considered a magnum. but I used the WLRM and the GM215M in my 7mm rem mag.

Great catch !!!!!
I miss quoted the chart and looked at the 210 M instead of the 215 m

That's the reason I use charts to keep from making stupid mistakes.

These primers have been tested and the chart shows the closest primers in burn/ heat test.

Hear is another chart that will help explain the heat range of different primers, along with the first chart.

http://www.castingstuff.com/primer_testing_reference.htm

http://www.handloads.com/misc/primers.asp

Thanks for correcting me and catching the type o

J E CUSTOM

 

[BUSTINDOGS]

Thank you J E I had no idea there was even such a thing as these charts before. That's why I ask questions here, because of the intelligent people here like yourself.

 

[FEENIX]

Great catch !!!!!
I miss quoted the chart and looked at the 210 M instead of the 215 m

That's the reason I use charts to keep from making stupid mistakes.

These primers have been tested and the chart shows the closest primers in burn/ heat test.

Hear is another chart that will help explain the heat range of different primers, along with the first chart.

Primer Testing Reference

Primer cross reference chart

Thanks for correcting me and catching the type o

J E CUSTOM

Jerry,

I too use reference charts --- somebody put in lots of time and effort into it and made it readily available for us all to use and enjoy.

Ed

 

[couesaddict]

In the notes below the primer results of one of the links it was mentioned that a wad of "newsprint" under the primer could result in better consistency by keeping granuals from entering through the flash hole. Could someone elaborate on that a little for me please? I've never heard of this before but am interested in better consistency any way I can achieve it. Thanks for all of the information that has already been posted as well. Very informative.

 

[J E Custom]

In the notes below the primer results of one of the links it was mentioned that a wad of "newsprint" under the primer could result in better consistency by keeping granuals from entering through the flash hole. Could someone elaborate on that a little for me please? I've never heard of this before but am interested in better consistency any way I can achieve it. Thanks for all of the information that has already been posted as well. Very informative.

I don't think that is a good idea and would worry that it might impede the powder burn.

It doesn't hurt for powder to get on the outside of the anvil because it will burn up at the same rate as the rest of the powder (It is common for some fine or ball powders to get in the flash hole). and it might even help the ignition and burn rate of some powders.

We go to a lot of trouble to clean and prep the flash hole and to stick something foreign under the primer just doesn't sound like a good idea to me.

J E CUSTOM

 

[couesaddict]

Thank you. I kinda had the same thing in mind but I don't have all that much experience so I thought maybe it was just something I had missed somewhere. This is why I ask before I act I guess.

 

[CliffM]

In the notes below the primer results of one of the links it was mentioned that a wad of "newsprint" under the primer could result in better consistency by keeping granuals from entering through the flash hole. Could someone elaborate on that a little for me please? I've never heard of this before but am interested in better consistency any way I can achieve it. Thanks for all of the information that has already been posted as well. Very informative.

First CabinTree sells products geared toward BlackPowder Cartridge Rifle shooters and the mention of wads under the powder are too. I do not believe that smokeless powder/ bottleneck case/ jacketed bullet would see any benefit from doing this.

I have been loading BPCR for years using pistol primers and wads of various types both at the bottom of the case before the powder is dropped or under the primer,being punched out as the primer is being seated. Others may have different reasons for doing this, mine is to dampen the flame of the primer as much as possible. The theory behind this is that blackpowder is always loaded to leave no airspace under the bullet and often shoots the best with some measure of compression. When the flame from the primer hits the bottom if the powder column it is thought that it can move the column and thus the bullet before the column itself begins to burn resulting in degraded accuracy. A softer flame is thought to allow the powder to light without starting the bullet into motion prematurely.
Whether there is any amount of fact to this I don't know. What I do know is that the target says it shoots better this way

Cliff