.357Mag reloading questions

[zguy]

Hi Everyone,

Looking to reload 357mag and .38spl
I have MS200 propellent and small pistol primers, which i believe is acceptable for .38spl.

As for .357mag, it would seem that the only available local powder that is available is S265.
Can anyone confirm if magnum primers for this powder is needed, or if standard primers are suitable.

[Ds J]

MS200 and SPP work well with .38Spl. Please check the reloading tables if you shoot a snubbie or small frame revolver - they have special reduced loads to protect the frame of the revolver.

Please be aware of the danger (possibility) of double charges, especially with MS 200, simply because the charges are small enough that two charges fit into the case. As a precaution, I always throw a double charge when reloading for handguns, and keep it aside to check the other loads.

Also: please read up on flash over (detonation) which can happen in loads with small amounts of powder. If memory serves correct there is a great discussion on this on this forum. The chance of it happening in .38Spl is said to be extremely small but I still find it good to have knowledge on the subject. Some reloaders advise the use of filling (paper/dacron) in cases when reloading very light loads - I did it with good results. I also read reports which advised against it.

There is a catch with 357Mag, but I cannot remember exactly what it was. It has to do with bullet weight and barrel length. S265 works better with 18" carbine barrels, but not so good with revolver hunting loads?

MP200 works very well with 357Mag, but is generally out of stock.

I would not use MS200 in 357 Mag, rather get an imported brand.

Also: remember to crimp the bullets, otherwise recoil kicks them out - it has happened to me.

[big5ifty]

Avoid MS200 when the case fill is very low. This will happen in 38 and 357. The chance of a SEE with less than 50% case fill is not worth the risk.

Somchem gives load data for 38 and 357 using MS200, it does not mean the powder is actually suitable for that application.

Rather use MP200 in the revolvers, and leave the MS200 for 9mm and smaller cartridges.