Primer questions

[Osuvet85]

I am brand new to reloading and I am confused about primers. What primer goes with what caliber? Small pistol goes up to 9mm? When do you use a magnum primer? On a magnum round? Small rifle primers cover what calibers? Large rifle? None of the books I've looked through (Lee manual, ABCs of reloading, Beginner's Guide to Reloading) cover which primer for which caliber. Thanks in advance.

[Jim Watson]

How strange, maybe you need more references.
My Lyman, Speer, and Nosler books specify primers, as does the Hodgdon website.

Primer BRAND is not critical; I have used about all US make Small Pistol in 9mm, for example.

[ghbucky]

The load specifies the type of primer used.

For example, Hodgdon's online data center shows that for a 9mm using 124gr Berry's the primer is CCI 500 Small pistol (in the right hand part of the header).

https://www.hodgdonreloading.com/rel...c=true&type=53

That would be CCI brand, #500 Small pistol primer.

[edit] I suggest you re-read your Lee and ABC book. They tell you this. I'll grab them when I have the time later and point you to where those details are.

As Jim Watson said, the BRAND of primer is not critical. It is what was used during the development of the load. BUT, this is why you always develop your load by using the start data and working your way up looking for pressure signs.

[Unclenick]

Welcome to the hobby.

There is no fixed answer, as 45 Auto and 308 Winchester, while both originally made for Large Pistol (LP) and Large Rifle (LR) primers, respectively, now have some brands of brass with pockets for small primers. This has come about for reasons to do with lead-free primers in the case of 45 Auto and because some match shooters and testing showed SR primers giving slightly more consistent velocities in the case of the Lapua 308 Winchester Palma cases with the small primers. So, you always need to double-check your particular brass.

In general, the primer pocket is usually chosen to fit the case head. Heads that are about 0.425" in diameter and smaller just in front of the rim will usually have small primer pockets, and larger-diameter ones will usually have large primer pockets, but there are exceptions, like the 454 Casull Magnum, which is a revolver cartridge that uses small rifle primers. One quick way to check is to look up load data and see what type it lists and use that. Hodgdon is a good source of that information. Use their site to look up any load of the caliber you are interested in, and it says what primer they used.

There are three sizes of primers. SR and Small Pistol (SP) are the same physical size but are not meant to be interchangeable, though some have successfully interchanged them in some circumstances; the general advice is to use the type your load data used, as changing primers can affect the pressure in some instances. LR and Large Pistol (LP) are the same diameters, but the LR primers are about ten thousandths taller and stick out of an LP primer pocket slightly when seated. In general, SR and LR primers have thicker cups than the SP and LP primers and are harder to ignite.

Magnum primers make more gas than standard primers. A primer has to partially pressurize a case so the powder burn will sustain, and the larger the case, such as a magnum case, the more empty space has to be pressurized, so hence the term "magnum" primer for primers that make more gas. However, a standard case can also have extra space in it if the powder charge doesn't fill it very well, so magnum primers can also be helpful in that circumstance. They can also be helpful with powders that are harder to ignite due to heavier deterrent coatings. The St. Marks spherical propellants market as Winchester Ball Powders are an example, as are their Hodgdon equivalents.

This article will explain some of this.

[RC20]

And then there is my 6.5 Lapua that ONLY comes in small rifle primer cases (vs the 6.5 Creedmore that per Unclenick has both, they are all out of the parent 30-06 case which I believe is the main driver generally)

I thought I could get 6.5 Lapua cases in Large Rifle Primers and I had a lot stored up, sigh.

Lately I have been able to pick up Small Rifle primers and have built up my stock though my next barrel is a 6.5 Creedmore.

[gwpercle]

On line data centers are nice , especially if you have a bit of reloading experience ...
But nothing beats having a few Printed Loading Manuals in front of you ... and if you read the information in the chapters that precede the loading data ... you will learn a lot .

Some things ... most things are not cut and dried yes or no ... primers have become very complicated ...45 acp cases can be found with small primer pockets...that's a first !
There seems to be an exception to every rule ... and no easy answer .
Get a few printed loading manuals to back up your on-line references ... and be careful who you get data from on-line . I have seen some very sketchy loads passed around and not everything on the internet is tested .
The manuals will tell you when and with what powder to use a Magnum Primer ... primer selection can get complicated . For the last 50+ years I have simply " gone by the book " used the components published and have never had any problems !

Here are my four go to manuals :
Hornady Handbook of Cartridge Reloading - latest edition
Speer Reloading Manual - latest edition
Lyman Reloading Handbook - latest edition ( #51)
Lyman Cast Bullet Handbook (cast lead bullet info and loading data) 4th edition .

These 4 books have helped me a great deal , the informative and how-to chapters are worth every penny as is the tested and reliable loading data .
Good Luck and Load Safe !
Gary

[RoyceP]

Originally Posted by Osuvet85

I am brand new to reloading and I am confused about primers. What primer goes with what caliber? Small pistol goes up to 9mm? When do you use a magnum primer? On a magnum round? Small rifle primers cover what calibers? Large rifle? None of the books I've looked through (Lee manual, ABCs of reloading, Beginner's Guide to Reloading) cover which primer for which caliber. Thanks in advance.

Loading manuals give specific recipes for every round. The primer is always specified.

[akinswi]

Originally Posted by Osuvet85

I am brand new to reloading and I am confused about primers. What primer goes with what caliber? Small pistol goes up to 9mm? When do you use a magnum primer? On a magnum round? Small rifle primers cover what calibers? Large rifle? None of the books I've looked through (Lee manual, ABCs of reloading, Beginner's Guide to Reloading) cover which primer for which caliber. Thanks in advance.

Read everything you can.

We are here to help.