Any advantage to using magnum primers over large pistol?

gramps said:

If I followed Lyman's data, all my .44 spcl would shoot is 650 FPS. So I go with Alliant and get 900 FPS. Is that dangerous? I think not!
gramps

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Look at the barrel length used for that data. Lyman tends to use fairly short barrels, typically a 4" barrel, and the powder manufacturers tend to use longer barrels for their velocity data. Alliant lists that they used a 5.6" barrel for their .44 Special velocities. At those barrel lengths, the extra 1.6" makes quite a difference in velocity, even if the load is the same.

900 fps can certainly be a SAAMI spec .44 Special load. Alliant publishes no over-SAAMI-spec .44 Special loads and with a 5.6" barrel, has three loads over 900 fps with a 250 grain Keith SWC. They list 6.9 gr of Unique for 921 fps, 8.0 grains of Power Pistol for 954 fps, and 13.0 gr of 2400 for 965 fps.

AFAIK there is no SAAMI or other definition for +P LOADS! Particularly for +P+!
I just look at the muzzle energy of the load against ones I am using. When in doubt I don't use it. With reloads I can always work up to the max; but with the 'FACTORY' loads all I can do is stuck with known (major) suppliers. I'm not that worried about blowing up a Ruger, Thomson, or +P rated S&W.

grobin said:

AFAIK there is no SAAMI or other definition for +P LOADS! Particularly for +P+!
I just look at the muzzle energy of the load against ones I am using. When in doubt I don't use it. With reloads I can always work up to the max; but with the 'FACTORY' loads all I can do is stuck with known (major) suppliers. I'm not that worried about blowing up a Ruger, Thomson, or +P rated S&W.

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There are SAAMI pressure specifications for four +P loads- 9 mm Luger +P (38,500 PSI vs. 35,000 PSI), .38 Special +P (20,000 PSI vs. 17,000 PSI), .38 Super Automatic +P (36,500 PSI, no data listed for a non +P load) and .45 Automatic +P (23,000 PSI vs. 21,000 PSI). This information is freely available in the ANSI/SAAMI Z299.3 document on SAAMI's website which shows pressure and typical velocity information as well as has detailed cartridge drawings of all current SAAMI approved pistol and revolver cartridges and a bunch of methodology to follow if somebody wanted to set up their own pressure/velocity test barrels.

There are no SAAMI specifications for +P+ loads.

THANKS!!

I believe there is one other SAAMI designated +P cartridge spec, for .257 Roberts.

grobin, there's plenty of written information out there on these topics. I continue to encourage you to study up!

NikA said:

I believe there is one other SAAMI designated +P cartridge spec, for .257 Roberts.

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That is correct, but it is in the rifle cartridge specs (ANSI Z299.4) and not the pistol and revolver cartridge specs.

Also note that the specs give typical bullet weights and velocities for the cartridge when they adhere to SAAMI pressure specs.