What is the difference between large rifle, small rifle and magnum primers. I assume size but when do you use what. I am currently reloading .25-06, .270, .30-06, .338-06 and am using Winchester Large Rifle primers for all the loads. I will soon be loading .375 H&H once my rifle is finished, should I use Magnum primers for this round?

Phoenix

Large and small rifle primers differ in size, as you would expect. The same is true for large and small pistol primers. Don't mix them. Use only rifle primers in rifles and pistol primers in pistols.

The difference between standard and magnum primers is that the magnums generally have a hotter and longer lasting flame. I say generally because there may be some standard primers that are actually hotter than another brand of magnum primer.

Magnum primers are intended for when you are using very large powder weights, most ball powders, and in certain situations, such as very cold weather. In other words, use them when there is a possibility that a standard primer may not ignite the powder properly.

Your best bet is to get yourself a couple or three of the good loading manuals and follow the recommendations that they give for primer type. After a while you develop an understanding of what works best.

The 06 based cartridges that you mentioned will all work with standard primers. The only exception I can think of is if you are loading 60 or more grains of a powder like 4831 or H1000 and intend to be shooting in very cold weather. But, if you do switch, drop back a grain or two and work back up.

For the 375 H&H it is probably a good idea to start with Magnum primers and stick with them for all loads. Many of your loads will probably work OK with standard primers but why complicate things with two different primers? The magnums will work just as well with the milder loads and they are probably best with the heavy loads just to be on the safe side.

I know some shooters who simplify things by using magnum primers for everything. That way they never have to worry about using the wrong one at a critical time. And as long as you work up a load with the magnums they they are perfectly safe to use.

One little trick. If you use both standard and magnums, try to find a brand that is a different color so you easily tell them apart. For example, the Winchester magnums are brass colored and the standard are nickeled. That way you'll always know what is what.

I'm tired.

Good Luck

Ray

thanks for your response, I have the Speer Manual, but the primer information is not real conclusive about the Large and Small rifle primers. It does list the primers used on the loads, but typically by brand; ie CCI 200, 250(magnum primer due to the 5 designation in the number), WLR, etc. The manual does have a good section on magnum primers and I like the idea of just using the magnum primers for everything. I appreciate your reponse.

All good advice! Another little trick you can use is a sharpie marker.
Myself, I'd recommend that you follow the reloading manual as you would any other cookbook until you have more experience under your belt. Mixing up primers won't necessarily hurt you, but failing to properly inspect and resize a case might. The big Lyman book is always a good place to start.

You may use magnum primers for all your loadings but the loads for "standard" cartridges would have to be worked up again. Magnum primers sometimes gives you a higher pressure so your powder charge would have to be reduced.
Some folks report good things when using magnum primers in standard cartridges but that hasn't been my experience. Some suggest that a magnum primer should be used if using ball powder in very cold conditions. I've never had any ignition problems, soooo, if it's got a belt on it, I use a magnum primer; if not, I use a standard primer.

I have found that mag primers often give a bit less accuracy in loads worked up for std. primers. My rule of thumb, if it uses more than 65gr +/- of powder, I start thinking magnum primers. You'll find the better loads for the 375h&h use med. burning powder & just over 70gr so you may do fine w/ a std. primer.