"magnum" v. "large" rifle primers

[another okie]

I'm still pretty new to reloading. In reloading some .30-.30 rounds I noticed that the Speer manual calls for using magnum primers with Winchester 748. I don't have any "magnum" primers. Are "magnum" primers the same as large rifle primers? Are there "magnum pistol" and "magnum rifle" primers or just generic "magnum" primers?

 

[Art Eatman]

"Small" and "Large" refer to the diameter of the primer and the primer pocket of the cartridge case.

Then, there are two levels of power for primers. The standard primer is just called a "primer"; those for the magnum cartridges are called "magnum primers". Magnum primers have a bit more "oomph" to get reliable ignition with the slower burning powders commonly used in the larger-case magnum cartridges.

Since with slow-burning powders in a non-magnum cartridge the ignition is more reliable with a magnum primer than with a standard, you'll occasionally see them recommended for "minor" cartridges.

So, to recap: You have large and small pistol primers and large and small rifle primers, so-called strictly because of the diameter. For both pistol and rifle you have regular power or standard primers and then the magnum primers.

Hope this helps,

Art

 

[Zak Smith]

Many people recommend using magnum primers when using ball powder.

-z

 

[another okie]

Well, the 748 is ball powder, so that makes sense.

I did load some 748 up awhile back with large rifle primers and noticed some uneven velocities. I just now noticed the little asterisk that says magnum primers used, so I'll head to the store.

The Speer manual says they used CCI primers 200 and 250 in .30-.30, and the ones I have are marked 200, so the 250 must be the magnums. The Winchester primers I have are marked WLR, which I assume means Winchester Large Rifle. I may also pick up another powder, just for comparison and since the 748 requires magnum primers.

I bought 748 because there were loads listed for it in almost all bullet types, and I wanted to try some of the small plinking bullets at 100 grams as well as the 150 and 170. It seems like for IMR and Vita they have used one powder for the light bullet and others for the heavier bullets, which is not very convenient for low-volume reloaders like me.

 

[Sunray]

"...100 grams..." You did mean 'grains' didn't you?
Magnum primers burn hotter than standard primers. Helps to ignite the powder.

 

[patentmike]

So the diameter is the only difference?
I have a bunch of Winchester "small rifle" primers that would fit in .357 cases. No problem?

 

[Black Snowman]

If you want start getting picky about primers it can get confusing so I'll try to break it down. hopefully it will make sense.

In large and small sizes you have four types

Standard Pistol
Magnum Pistol
Standard Rifle
Magnum Rifle

You actually have 3 sizes because large rifle primers are taller than large pistol primers.

Rifle primers are harder than pistol primers to handle the higher typical pressures and harder hammer strikes of a rifle. They are also more potent to ignite the powder in the larger rifle cases.

Just to add to the confusion there are differances in hardness and potency between brands as well. This is why it's important to start load development over when you get a differant brand or type of primer.

Depending on the brands there may be some overlap in potency and hardness between small pistol magnum and small rifle standard.

The only pistol cartridge indeded to use these primers is the .454 Caussul and they can cause light strikes in many guns because of the harder primer.

You never want to use magnum primers in small capacity cases like .45 ACP, .40 S&W or 9mm. I don't even recommend the Winchester Std/Mag combo primers in the .40 S&W or 9mm.

See, clear as mud!

 

[ClarkEMyers]

I do believe the Speer manual covers this

I do believe the Speer manual covers this if you read all of it - at least most editions do.

For what it's worth I do believe in starting with loads as listed before I decide I know better. Often the manual load will have been pressure tested at different temperatures or positions that I didn't try. One afternoon at the bench doesn't make me smarter than Dave Andrews or Ed Matunas - though I may know more than some of these young guys.

 

[patentmike]

I loaded a few .357s with 13.5 gr of H110 and 180 gr JHP.
I primed them with Winchester small rifle primers because I happen to have a bunch of them lying around now that I got rid of my .454. Now I have to borrow a chrono and see if they are any different fromt he pistol-primer version.

 

[rugerfreak]

Then there are military primers that are hardened to prevent slam fires.

 

[another okie]

Bought some "large rifle - magnum" primers. They are some honkers! I did read the Speer manual before beginning to reload and had noted some loads asking for magnum primers, but I don't remember any discussion of types of primers, though there is a long section on the history of the different chemicals used.

I guess I missed the note on Win 748 because, frankly, I was just overloaded with information when beginning to reload. I'm not very mechanical and there was a lot to learn. I still don't really have it all down, as shown by my "grams / grains" mistake. (I do know the difference and weigh carefully.)

The Speer manual often puts very important information buried away at the end of a long paragraph of vague and unimportant stuff.

 

[ClarkEMyers]

Speer emphasizes products from related compnanies

There is an adequate primer discussion pp 35-36 of the current #13 Speer manual but it does concentrate on Dick Speer's primers (CCI) as they evolved along with the other brands and their products that have gradually come under common ownership (Blount).

It pays to know that the brands mentioned mostly share a common ownership - not a bad thing of itself - I suspect the writing may be a little strained to emphasize their brands and to avoid mentioning other products and other men when such might come naturally.

A complete view of the industry may mean reading about other products in other brands in other books.

 

[Third_Rail]

Black Snowman, the .500 S&W cases from Starline use small rifle primers too, IIRC.

 

[Khornet]

A few years back

I loaded up a bunch of .30-'06 with 748 and standard large rifle primers. If I recall correctly, the manual said COULD use magnums, or SOME folks preferred magnums, which I didn't have, so I used standard.

Every round was a hangfire: click......BOOM. After about 5 rounds I stopped. Later I read another source insisting on magnums with 748, and loaded the same stuff with magnums: voila! Great accuracy, no hangfires. The ball powders just seem to need a hotter spark or sumpin.

 

[WhoKnowsWho]

I have a bunch of Winchester "small rifle" primers that would fit in .357 cases.

I remember reading a manual and it specifically mentioned don't assume that because a round is called "magnum" that it requires a magnum primer type to be used. Follow the data, and all will be well.

Using rifle cases in a handgun round... not a good idea, could cause excess pressure among all sorts of other problems.

 

[Black Snowman]

Third_Rail, makes sense. I haven't really looked at the .500 S&W that closely. I'll have to take a look and see if the factory ammo has SR primers next time I'm at Cabela's.

 

[Rockstar]

.40 Supers also use small rifle primers. Lots of folks use 'em in 9mm reloading.

 

[ClarkEMyers]

9X23 - superface loads often go small rifle

9X23 - superface loads often go small rifle

 

[patentmike]

"Using rifle cases in a handgun round... not a good idea, could cause excess pressure among all sorts of other problems."

What sort of other problems? I couldn't think of any, so I fired a few (180 gr XTP, 13.5 gr H110, .357) in my Ruger and see no signs of higher pressure. They look just like factory primers in Winchester white box I fired for comparison. I did have one light strike, so I would only use it for practice ammo. Granted, rifle primers may be designed to throw a longer "spark", which may not be needed in a pistol case, but is H110 in a relatively small case really going to burn a whole lot differently either way? I don't have the measuring capabilities to pin it down exactly, but I doubt it.

 

[patentmike]

On the other hand, maybe I just got lucky.
Better to have a few extra rifle primers laying around until I figure out what to do with them than to risk injury or damage.

 

[cracked butt]

When you switch to magnum primers, make sure you back off your load from the maximum and work up again, they will change your pressures.