Standard vs magnum primers fps?

[willy]

How much difference in velocities will there be with the same loads when switching from standard to magnum primers in magnum handgun loads?

[FergusonTO35]

Totally depends on the powder and charge. If using common pistol powders and charges you'll probably see a much wider extreme spread. What cartridge and load are you shooting?

[Hick]

In my Ruger 357 revolver with a bout a 160 grain bullet I see around 50 fps difference with HP-38/W231, but lots less difference with Titegroup. You can't generalize because it depends on how hard the powder is to ignite-- which varies, and then also depends on the bullet weight.

[BLAHUT]

I have tested every flavor of primer I could get my hands on, I only changed the primers in my 45/70 load. All the primers were about the same across the board, across a coronagraph, the only thing changed was the primers. Now except CCI or federal primers, those two gave me 100FPS more, all the rest were with in a few FPS each. This was a test of only primers, nothing else.....

[black mamba]

Federal 150s are the weakest, and CCI350s are the strongest. With harder to ignite slower powders you might see as much as 100 fps difference between the two. With faster easy to ignite powders you might only see 25 fps difference, or even less.

[FergusonTO35]

I'm going to switch to standard primers for my next batch of .357's. I have some wandering elevation, and suspect that the magnum primers are pushing the boolit out of the case before the powder is fully ignited, thus causing variable pressure.

[Larry Gibson]

How much difference in velocities will there be with the same loads when switching from standard to magnum primers in magnum handgun loads?

I've done considerable test of pressure and velocity with different primers. You might read my test results and conclusions in the following threads;

https://castboolits.gunloads.com/showthread.php?417830-Comparison-of-various-SP-and-SR-primers-in-the-357-Magnum

https://castboolits.gunloads.com/showthread.php?423061-9mm-with-SP-and-SR-primers-psi-tests

https://castboolits.gunloads.com/showthread.php?381165-Test-of-Hercules-vs-Alliant-2400-in-the-357-Magnum-with-6-different-primers

As FergusonTO35 says it "Totally depends on the powder and charge."

[willy]

Thanks to all you guys with the info.
And a big thank you to Larry Gibson for all the time and testing he has done.

[Electrod47]

Good info here.

[Messy bear]

Federal 150s are the weakest, and CCI350s are the strongest. With harder to ignite slower powders you might see as much as 100 fps difference between the two. With faster easy to ignite powders you might only see 25 fps difference, or even less.

This lines up with my testing as well. As mentioned it depends on powder used and all the other variables.
In my loading with LP’s -
Cci 350
Unis Ginex LP mag (my favorite for hard to ignite ball powders)
Fed 155
Mag tech 2.5
Rem 2.5
Win old silver LP
Cci 300
Win gold colored LP
S&B LP (one of my favorites as it’s so consistent and clean)
Wolf LP
Fed 150
Fiocchi LP
Tula LP

[Messy bear]

That’s in order of hottest on top to softest on bottom. Again just my findings. YMMV

[black mamba]

I agree with the S&Bs-- they produce excellent light target loads.

[Messy bear]

Some of my results were from pressure testing done in western powders lab in miles city mt. That was during one of the first primer shortages so we only had the two versions of the Winchester LP, Remington 2.5, cci 350, and federal 155.
The results were vey revealing. After that we did chrographing at home to kinda fill in the blanks so to speak.
Internal ballistics are very elusive but with careful observation and testing as Larry and others have done, we can all know more about this subject.