Large Rifle Primers and Large Rifle Magnum Primers

[dobedo]

In reloading my 30/30 and 45/70 always large rifle primers were called for no matter which powder was used. When I started reloading my .500 S&W magnum all the Hodgdon powders called for large rifle magnum primers when all other powders called for the use of large rifle primers.

I wrote Hodgdon several times and have never received a reply on why the use of the large rifle magnum primers. So, I decided to do some testing to see if there was a difference. Keep in mind my testing was by the seat of the pants not scientific at all.

First test I loaded up some Hodgdon powders as recommended with large rifle magnum primers. The outside temperatures were 30 degrees on my first test. A 75-yard target iron sites using a BHA .500 carbine and 25-yard target using a BFR .500 revolver. Then I did the same test with standard large rifle primers and did not see any changes in accuracy or burn rate based on cases.

I completed the second test the same as the first except the outside temperature was 83 degrees. Again, there were no difference in accuracy of powder burn when comparing the cartridges.

I searched the WWW and could not find any reason why the large rifle primers were only used in Hodgdon powders. I did find in Europe and other countries they only used large rifle primers in the .500 S&S cartridges no magnum primers. The question still remains why I did find an UK guy that did extensive testing on primers. However, it did not answer the question why?

Here is his site which does help understand the difference between large rifle and large rifle magnum primers. But still does not answer the question why? Any thoughts form the group?
Large Rifle Primer Performance by Laurie Holland | Target Shooter Magazine

 

[bigpower491]

I'm thinking Hodgdon powders for the 500 S&W would be of the spherical nature. Like H110. I believe the thinking is the magnum primer does a better job of lighting those types of powders off. I'm my testing with full on 296 loads in 454 Casull, there wasn't any difference in small rifle magnum or standard primers. But then again there's a big difference in the amount of powder the 454 uses and the 500 S&W. Talking with a THR member that shoots 460 regularly, I was blown away by the amount of powder those X frame cartridges use.....the equivalent of a 30-06 charge in a pistol case. That's some big power

 

[dobedo]

O

I'm thinking Hodgdon powders for the 500 S&W would be of the spherical nature. Like H110. I believe the thinking is the magnum primer does a better job of lighting those types of powders off. I'm my testing with full on 296 loads in 454 Casull, there wasn't any difference in small rifle magnum or standard primers. But then again there's a big difference in the amount of powder the 454 uses and the 500 S&W. Talking with a THR member that shoots 460 regularly, I was blown away by the amount of powder those X frame cartridges use.....the equivalent of a 30-06 charge in a pistol case. That's some big power

Of the Hodgdon powders I use CFE-BLK, Titegroup, Longshot, and H110 for the .500 with no seeable difference in primer types. The other powders I use are Ramshot Enforcer, Alliant 2400, and Accurate #9 for the .500 all work well.

 

[bigpower491]

O


Of the Hodgdon powders I use CFE-BLK, Titegroup, Longshot, and H110 for the .500 with no seeable difference in primer types. The other powders I use are Ramshot Enforcer, Alliant 2400, and Accurate #9 for the .500 all work well.

You might only see a difference via chronograph. If the standard force LRP is working for you, that's a plus....They're generally a few dollars cheaper, and in this day and age, every little bit helps

 

[243winxb]

Starting & mid- range powder charges, may perform better with magnum primers.

https://www.shootingtimes.com/editorial/ammunition_st_mamotaip_200909/100079

 

[mdi]

https://duckduckgo.com/?q=standard+vs+magnum+primers+interchange?&atb=v314-1&t=chromentp&ia=web

https://www.shootingtimes.com/editorial/ammunition_st_mamotaip_200909/100079

 

[dobedo]

Starting & mid- range powder charges, may perform better with magnum primers.

https://www.shootingtimes.com/editorial/ammunition_st_mamotaip_200909/100079

Thanks, a good read but still leaves questions. I have run across many sites that contradict each other. Powder Through is just one of them saying to use any MFG large rifle primer for Hodgdon powders and all other powders. .500 S&W Magnum Load Data (powderthrough.com)

I will chalk up the differences as a mystery.

 

[dobedo]

https://duckduckgo.com/?q=standard+vs+magnum+primers+interchange?&atb=v314-1&t=chromentp&ia=web

https://www.shootingtimes.com/editorial/ammunition_st_mamotaip_200909/100079

Some good reading except using Magnum primers to replace standard primers. More data that leans toward whatever you have use with caution. Also, powder burn rates are not discussed just start a minimum and work up. Thanks more stuff to ponder.

 

[bigpower491]

I really wouldn't worry too much about it, especially if you're getting good results with the standard force primer. Remember, these big power handgun cartridges operate at pressures you normally see in rifles, hence the design calls for a rifle primer.
Are you using a chronograph? That will certainly show you the difference between the standard and magnum primers. And believe me, you will see the difference
These big cartridges digest a heap of propellant at a time, hence the need for a bigger spark to light em off consistently. If you are able to get good consistent results using a standard primer in place of the magnum primer, my opinion you're ahead of the game.
I personally wouldn't give it much thought from that point on, unless you're getting spotty ignition or real sooty cases and unburnt powder.
If they're leaving acceptable to you holes in the paper, shoot em up

 

[dobedo]

I really wouldn't worry too much about it, especially if you're getting good results with the standard force primer. Remember, these big power handgun cartridges operate at pressures you normally see in rifles, hence the design calls for a rifle primer.
Are you using a chronograph? That will certainly show you the difference between the standard and magnum primers. And believe me, you will see the difference
These big cartridges digest a heap of propellant at a time, hence the need for a bigger spark to light em off consistently. If you are able to get good consistent results using a standard primer in place of the magnum primer, my opinion you're ahead of the game.
I personally wouldn't give it much thought from that point on, unless you're getting spotty ignition or real sooty cases and unburnt powder.
If they're leaving acceptable to you holes in the paper, shoot em up

Getting some good results, no unburnt powder as far as punching holes, 100yards with the carbine 4–6-inch groups and at 50 yards with the revolver 4-inch groups. I think a chronograph would be useful if only for a peace of mind putting one on the list. I like punching holes in paper so I can keep up my skills for hunting season. Also, there are some loading sites that list standard rifle primers for the Hodgdon powders.

 

[Mk-211]

I have never used magnum primers for .454 or 500 S&W. Never had an issue with either caliber.

I think if I lived in a climate like Alaska or hunted in extreme cold weather, I would.

Just don't need it, plus you need to pay more attention to load data, that requires magnum primers. They do burn hotter and raise pressures.

 

[.38 Special]

I use standard large rifle almost exclusively in the .500 S&W. The only time I go with Magnum primers is when using H110.

 

[bigpower491]

I have never used magnum primers for .454 or 500 S&W. Never had an issue with either caliber.

I think if I lived in a climate like Alaska or hunted in extreme cold weather, I would.

Just don't need it, plus you need to pay more attention to load data, that requires magnum primers. They do burn hotter and raise pressures.

Agree.
Not to hijack, but when I first started with 454 I did, as I was using 296 and thought i needed too. But I figured out soon enough it wasn't necessary, irregardless of powder. The rifle primers are hot enough.


I guess the only other thing I can add to this topic is it's worth ones time to reference a few different data sources and see what they're using in their tests. One manufacturer may use a standard and another a Magnum for the same propellants and similar charge weights.
Let's say for instance Hodgdon shows data for X bullet, but specifies the magnum primer, and then X bullets manufacturer shows the same bullet, tested with the same Hodgdon powder, but done with a standard primer. I reckon my conclusion would be both primers work. If one ran into issues in load development, it would give one another option towards correction.