Using standard primers for 357 Mag

[cpatbay]

Lyman's reloading says to use mag primers for 357 mag. Do I really need to use mag primers or are standard primers just as good?

[rg1]

Depends on the powder you use. Slow powders like Win 296 or H110 need the magnum primer. AA#9 works good with standard primers and Accurate Arms manual #1 used standard primers while later manuals they tested with magnum primers. I've read that 2400 powder works with a standard primer. Again it depends on powder speeds and in cold weather the magnum primer might be better?

[thenodnarb]

I use standard primers with H110 in 357 loads. It works, but it is very dirty(presumably from unburnt powder).

[cpatbay]

What about Unique, W231, Titegroup?

[rromeo]

I use standard primers with Unique.

[thenodnarb]

You may not get the speed you want with a non-magnum powder. Faster powders build pressure so fast that you can't safely load it as fast as .357 should go.

['ol shooter]

Standard primers with Titegroup is what I use. If all you have is Magnums, reduce the powder weight by .10 gr.

[mark501w]

Unique was originally loaded in .357 Mag , I could never get it to shoot accurately. I use it in other calibers with std primers.

[sghart]

CPATBAY,

There is a lot of confusion on this topic.

To all reloaders insisting on using magnum primers in any round labelled "magnum" consider this.

The 357 mag was developed in the early '30' before there were even magnum primers available. For decades the 357 magnum performed flawlessly with 2400 powder and standard primers, (which is a classic and still favorite). Aso, the original 357 cases used large primers, not small.

Two things happened. The cases switched from large primer to small primer and surplus rifle powder became cheap and readily available. When surplus military rifle powder flooded the market handloaders experimented with them in pistol calibers. They were getting inconsistent ignition and poor accuracy. At the beginning intrepid handloaders scrounged up the existing 357 cases with large primer pockets and that fixed the ignition problems. As this supply dried up primer manufacturers invented the small pistol magnum primers.

In most powders a magnum primer is unnecessary. In fact, it can lead to extreme ES numbers, pressure spikes and poor accuracy. The only 357 mag case separation I have experienced in 28 years and thousands of rounds was from a magnum primer with AA#7 powder. I was using the magnum primer because I got caught short and that is all the store had.

In what has to be the biggest surrender to the uneducated public in firearm history the powder manufacturers started listing magnum primers for a lot of their powders. I talked to a representative of Sierra Bullets 3 years ago at a trade show about this very subject. He was just as dismayed as I was. He said that todays reloaders won't bother to do any research in a book but get their info from cubicle commandos on the interwebs. These "experts" insist that if it says magnum on the brass then it has to say magnum on the primer and magnum on the powder, etc.

The surrender part was necessary to keep their products financially viable with low IQ customers. And he is right. I don't know how many times I have heard Guys that should know better say some crazy stuff.

Bottom line, magnum primers are desirable in some applications: hard to ignite powders, cold weather, etc. But don't buy magnum primers just because you load for a magnum round.

[bjl333]

If you're loading softer target loads then the standard primers would be fine. If you're going for the gusto then use the magnum primer. W231, Unique, Bullseye, I use standard. H110, 2400 I use mags...

[socalnonsage]

What about Unique, W231, Titegroup?

I use standard for Titegroup (and Autocomp).

[wild_weasel]

I use standard primers with Bullseye, Unique, and 2400, with H110 I use magnum primers.

[Cowboy T]

I use chiefly Bullseye, Titegroup, and 2400 for my .357M loads. With all three of these powders, I use regular primers. Matter of fact, my favorite .357M load is with 2400 and standard primers.

Only with H110/W296 do I use magnum primers, because that particular powder's harder to get ignited.

[Enfield47]

Anyone using 700x for their .357 reloads? If so, what primer is best with that powder?

[Cowboy T]

For 700x, standard primers.