Regular or Mag Primer for 2400?

[wanderinwalker]

Okay, I think the title asks my question: Does 2400 require a Magnum primer for consistent ignition or will a regular primer suffice? This is going to be in a .357 Magnum tossing 158gr XTPs and 160gr Cast Performance WFNs.

I've always loaded .44 Magnum with 296 for full-tilt boogie, with either WLP or CCI Magnum primers. This "medium bore" is a new animal to me, and I picked up some 2400 after shooting some in a family member's reloads that proved very accurate in my new-to-me S&W M-19. I've settled on a light dose of W-231 and a 158gr RNFP .38 load for general Saturday morning plinking, but now I'm looking to get on the gas and load some hotter ammo to carry in the woods (and beat the steel plate on the rifle range ).

Thanks all.

 

[loadedround]

I would use a SP magnum primer for your 357 load. In fact most loadings show a magnum primer with the slower burning powders.

 

[Naear88]

2400

I use reg small pistol primers with my 158 gr .357 and 2400 powder with great results...

 

[rcmodel]

You may get more consistent accuracy and a smaller extreme deviation in velocity by using Standard primers with 2400.

Mag primers are generally called for only with ball powders like WW-296, H-110, etc.

2400 is an easily ignited flake type powder.

rc

 

[buck460XVR]

I too only use standard primers with 2400, no matter which magnum I load for.

 

[Steve C]

2400 is easily lit and doesn't need a mag primer. Magnum primers drive up pressures with 2400 and I've had pierced and cratered primers with .357mag 158gr JSP loads under 14grs of 2400 when using a mag primer while a 14.0gr load using a standard primer shows no signs of high pressure and delivers an average velocity identical to factory published ballistics.

Speer #13 manual specifically says to use standard primers with 2400 in the .357 mag and the magnum primers produce high pressures. This is a departure from previous manuals BTW.

 

[wanderinwalker]

Thanks!

I forgot to add, I ask because I noticed Alliant's freebie data indicates the use of standard primers, while (IIRC) the last time I checked the .357 Magnum loadings in Nosler and Lyman they indicated Magnum primers.

 

[bluetopper]

As stated, with 2400 powder all that is needed is standard primers in any caliber it is used.

 

[Rollis R. Karvellis]

I, fond that using a magnum primer with 2400 I had better groups, and no unburnt powder.

 

[LTR shooter]

I, found that using a magnum primer with 2400 I had better groups

That was the case with the 357 load I tried a few years back - the 2400 loads with the mag primer were significantly tighter than the standard primer load.

 

[warnerwh]

In my loads for my .357 and .44 I use CCI standard primers with 2400. Much better groups. Same thing happened when using Unique for mid power loads. Only with 296 do I use mag primers.
If someone can explain why the magnum primers open groups up so much I'd like to know. I've heard many people that came to the same conclusion. I'm thinking it may be less consistent ignition but that's only a guess. Thanks

 

[Rollis R. Karvellis]

It come's down to the gun, and load combination, that's why there is not a one powder, or one primer do all.

 

[472x1A/B]

I agree with Rollis. The gun and the load. With my Redhawk 44 I use Mag. primers/2400 ,and in my GP 100 Std. primers/2400.

 

[LTR shooter]

If someone can explain why the magnum primers open groups up so much I'd like to know.

A few years ago when testing the accuracy of various loads I mounted a scope and shot from a benchrest , two indentical loads with the exception of std. and mag primer. The left was the standard primer and the right is with the magnum primer:


The right group is more or less what I can fire consistently at 25 yards with my H110/296/AA #9 loads with the same bullet and mag primer. The left is more like a 50 yard group with those powders.

It come's down to the gun, and load combination, that's why there is not a one powder, or one primer do all.

Exactly , one needs to find what works best in their own gun.