Primer question

[equalizer]

I'm loading .44mag and in the manuals I have, most call for cci300. Question is can I use a federal 150M instead. It's a match primer but not magnum. I don't know the difference between these two. Also if anyone knows or has a link for good primer info/understanding I'd appreciate it. Thanks

 

[Walkalong]

What powder do you intend to use?

 

[equalizer]

2400 and H110 and 296

 

[.38 Special]

A magnum primer is simply hotter, or at least is supposed to be*. The idea is that large amounts of powder -- and/or slower burning/harder to ignite powder -- needs a hotter spark to get it going. So large amounts of H110 (which for all intents and purposes looks to be the same thing as 296 and might even be coming out of the same spout) in a .44, for instance, usually want magnum primers. Powders like Unique, though, usually don't want or need a magnum primer even when used in magnum cartridges approaching magnum velocities.

The famous Elmer Keith .44 Magnum load with 2400 and a 250 grain LSWC was developed with standard primers, and is still a valid load today. Elmer was adamant that magnum caps not be used, as he claimed they increased pressure to dangerous levels. And usually, magnum primers do increase velocity and pressure. But Ross Seyfried noted, decades later, better velocity and lower pressure with H110 and magnum primers in the same cartridge. So as with most things internal ballistics, there aren't any absolutes. Most of the time you can get away with interchanging primers in the .44 Magnum, but sometimes you're asking for trouble. It really depends on the powder type and amount, the bullet style and weight, and even the amount of crimp you're using.

Clear as mud?

*There is some debate over whether all magnum primers are hotter than all standard primers. It may be the case that some company's magnum caps aren't as hot as other company's standard ones. Haven't tested it myself, so can't say for sure.

<edit> And seeing the powders you intend to use, in your shoes I would use the standard primers with the 2400 and buy some magnum caps for the 110/296.

 

[Griz44]

Winchester Large pistol primers claim that theirs is good for either application, even so stating on the box they sell it in. I use them for 45ACP, and have not tested them on any magnum loads.

 

[Walkalong]

2400 and H110 and 296

No, yes, and yes, generally speaking.

 

[ants]

Here's a quote from CCI's web site. The "conditions" referenced are large case volume and large powder charges:

Magnum primers are engineered to produce a hotter flame of longer duration to meet the needs of the above conditions. However, these characteristics often require a charge weight reduction to keep pressure under control. For this reason, use Magnum primers only where recommended in published loading data.

Our research indicates that some propellant/cartridge combinations do not require Magnum primers at the maximum load level, but can at the start load level for reliable ignition. When we find this, we use Magnum primers for all loads with that propellant.