I can remember 20 years ago I used to load 357 158gr JHP with 15 grains of H2400 powder. What I can't remember is if 2400 requires a magnum small pistol primer. Seems like I used a mag. My current Speer reloading book shows 14.8 gr of 2400 as a max load using a standard small pistol primer. Does the newer 2400 formulation not require a magnum primer anymore?

-Rick

For my hunting load, as fired in a Model 28, I use 15.4 grs. of 2400 under a 158 gr. JHP bullet. This a hot load, and approximates the original Elmer Keith one. No signs of excessive pressure in my 28, is very accurate. I also use only standard primers. Beefy01 NRA Patron Member

2400 does not require a magnum primer.

my book states not to use mag primers with 2400

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I use 14 grains with a standard primer. Everything I have read has said that 2400 does not require magnum primers.

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2400 + magnum primer = excessive pressure

If you start using H-110 or WW 296 (same powder), then use a magnum primer.

Magnum primers will increase pressures with 2400 quite significantly. Current Speer manuals make a reference to this and recoment using only standard primers with their loads.

Years ago using magnum primers I couldn't load much over 13.5grs of 2400 behind a 158gr JSP/JHP bullet without running into obvious pressuresigns like piecred and cratered primers. Usning CCI standard primers I currently load 14.0 grs behind 158gr Remington or Winchester bullets and get a chronograph measured velocity of 1,247 fps out of my 4" M66 which pretty much matches factory ballistic charts from a 4" vented test barrel with the same weight bullet.

I have read things from the "greats" of our hobby. Skeeter, Keith and others and all of them say not to use magnum primers with 2400, not needed.

True enough, EXCEPT, I'm not sure what they had for chronographs back then. I do know this, the ES and SD come down significantly when you use magnum primers with 2400.

That being said, most of my testing has been in 44Mag. I have reduced the charge from what Elmer said to use with a 250gr LSWC and used magnum primers and had great results.

Seeing that I can reduce the charge weight and get the same velocity by using magnum primers, that would seem to be cheaper too, as magnum primers cost the same as standard.

FWIW

2400 does not require a magnum primer.When loading to less than max,I will load with mag primers but when going for a full load,better to stick with standard.Lab results show that to work best pertaining to velocity/pressure ratio.

For years,I used a Speer 158 gr jhp with 15 gr of 2400 + standard primer.As always,work up when loading to max.14.5 gr did very well with just a tad less pressure/velocity.

Thanks for all the input. I'll use standard primers.