2400/magnum primers??

[ultratec1]

I am in the middle of loading my .357 loads with 14.9gr of 2400 and I'm using magnum primers. I have shot 30 loads so far and they shoot great, however someone told me not to use magnum primers with 2400 because it could cause damage. Is there any truth to this, they shoot great using them.

 

[rcmodel]

Mag primers are not necessary, or recommended by some folks who should know.

Pressure spikes have been reported with max loads.

You didn't mention what weight or type of bullets you are using, but you should be O.K. with 14.9.

rc

 

[CraigC]

Standard primers only for 2400.

 

[ultratec1]

Im using 125gr xtp. Can/will anything happen?? After testing the rounds and seeing how they grouped I went ahead and loaded 250 rounds. Is this going to be a problem??

 

[rcmodel]

No.

You are using basically using not much more then a starting load with 125 grain bullets.

14.9 would be Max or near Max with 158 grain bullets.
17.7 would be a Max load with 125 bullets.

And that would be something to be more concerned about.

rc

 

[gamestalker]

Stick to standard primers with 2400. I have personally noticed spiking with 2400, especially when I got beyond mid range data.

GS

 

[Grumulkin]

Gentlemen, pressure "spiking" has NOTHING to do with using magnum primers. If you are running on the ragged edge of high pressure with standard primers and substitute a magnum primers, then there might be a problem. If you work up a load with magnum primers or are loading at the lower end of recommended powder charges, magnum primers aren't going to cause random and mysterious pressure spikes.

You don't need a magnum primer with 2400 but they aren't going to hurt anything either.

 

[Maj Dad]

I started using magnum primers with 2400 when I had a lot of unburned powder, but there is a train of thought that in these cases the bullet may be too light, or the powder charge is light. I am not sure about that, but I do know that I had less unburned powder with mag primers, though it did not disappear (without changing the powder charge).

 

[sghart3578]

I tend to agree with Grumulkin. I use a lot of 2400 in 357 mag. I routinely shoot 14 gr under a 158 gr bullet, jacketed or LSWC. I have tried both standard and magnum primers. The accuracy was a little better with standard primers. I attribute this to the fact that my extreme spread readings were much worse (avg 110 fps vs 40 fps) with magnum primers.

 

[rcmodel]

I attribute this to the fact that my extreme spread readings were much worse (avg 110 fps vs 40 fps) with magnum primers.

And that in a nutshell is why you should use standard primers with 2400.

rc

 

[joed]

A long time ago when I was taught reloading I was taught when the powder charge was over 8.0 gr in a .357 that magnum primers should be used. I've lived by that rule for 36 years. Looking back through my mid 1970 manuals I see lots of magnum primers used with loads of 2400.

You can get by with a standard primer too. However, I'd want that mag primer if I was shooting outside in cold temps.

 

[rcmodel]

The thing is though, .357 factory loads used standard primers & 2400 for about the first 30 years of it's existence quite nicely.

Magnum primers were not even invented until well after WWII when ball powder became into widespread use.

That is the only reason they were needed.

rc

 

[Bullseye25]

I've loaded and shot about 300 rounds of 158gr fmj over 14.9 gr of 2400 with magnum primers without any issue or overpressure signs. (CCI 550)

 

[Grumulkin]

I started using magnum primers with 2400 when I had a lot of unburned powder, but there is a train of thought that in these cases the bullet may be too light, or the powder charge is light. I am not sure about that, but I do know that I had less unburned powder with mag primers, though it did not disappear (without changing the powder charge).

Many are aware of high pressure signs and few are aware of low pressure signs. Unburned powder in a barrel is a sign the pressure isn't optimal for the type of powder being used. In some guns though, because of pressure limitations in that particular firearm, pressures with safe loads will always be such there will be some powder residue in the barrel.

As for which primer to use, I would say that if you aren't happy with the accuracy of your load, then try several. Most of the time using a magnum primer in the smaller cases will not improve accuracy even when using ball powder and sometimes you'll get better results with a magnum primer with a stick powder in a medium sized case.

 

[TennJed]

Good thread guys, great info