Primers- probably dumb question

[tn_junk]

In looking for data to develop loads for my new .460 S&W Magnum (Encore Katahdan Rifle Barrel), I am finding suggestions for use of both large rifle and large rifle magnum primers.
What exactly is the difference? And what is the difference between Large Rifle and Large Pistol Primers? Small Pistol and Small Rifle Primers?
Not trying to mess with any load data, I am going to go by the book. Just curious.


Thanks

alan

[Kurt L]

You have different things but to keep simple.

mag primers produce more fire flash

rifle primers are heavier or thicker shell to take more pressure than pistol primers.

large and small are just that a small rifle or pistol primer is smaller diameter than the large primers.

[Tom W.]

If you'll take your calipers, you'll also see that Large Rifle primers are a bit taller than Large pistol primers.

[Scibaer]

not to highjack here, but, are they any differences between primers as fas as manufacturer goes ?
like a difference between CCI and Winchester or Remington ?

[Lloyd Smale]

a good rule of thumb is that if your using ball powders that are on the slow side of the burning scale use mag primers for faster burning powders use std primers. the thing that has to be considered though in your case is that in the smith 500 if you are using rifle primers the std rifle primers are allready for the most part as hot as a mag pistol primer. The only real way to know is with a chronograph. You need to use the primer that gives you the best accuracy and consistant velocitys. There are big differences in brands of primers. Again without alot of experince you are probably best served with a chronograph to find the right one for the powder your using. What makes it difficult to give specific answers to what is right is that pressure has alot to do with it. Some powders burn better with higher pressure loads. Take aa9 for instance. I use it alot and find its very primer sensitive. If a guy is say using it in a 44 mag with 250 grain bullets. Sometimes when loaded down slightly, say at 1100 fps it is tougher to get good burning then if its loaded to 1400 fps. You can get away with standard primers at 1400 fps but when you drop down to 1100 it takes a mag primer to make up for the lack of pressure and get good standard deviation readings.  As to differnces in primers you will find that a cci mag primer is about the hottest mag pistol primer followed by feds and remingtons which are about a toss up with wws comming in last. Not that the ww are an inferior primer its just that you have to keep it in mind and pick a primmer for your applicatiion. For example if i was loading the about senerio and wanted to run that 250 at 1100 fps the first primer id try is a cci mag as id know that it need some extra spark because i need to light off that low pressure load. If i was running the 1400 fps load id probably try the ww primer first. Nothing is wrote in stone though and you might find that your gun and your bullet design might prefer the fed primer. Another exception, at least in my experience is the big cases like the linebaughs and the smiths. For the most part if your using slow powders in them, your using alot of powder and they usually will like a hot primmer to get them lit off. When loading for the big cartridges unless im loading plinking loads with real fast powders the first primer i will try will be a cci 350. Now i probably  really have you confused.

[victorcharlie]

There was a post on another forum, and for the life of me I can't remember which one......

I had photographs of different primers firing.......

There was a big difference between them.....what surprised me was the Remington large rifle primers.....they had a huge spark......

I'm still looking for the link.......

[Old Syko]

A little helpful info on primer dimentions can be found at the link below.

http://www.jamescalhoon.com/primers_and_pressure.php

[carbineman]

Sometime back a bullet company (can't remember which one) did a test on primers and ranked them from coldest to hottest flame.At the time before publishing the results of this test, they went out and purchased all new primers with different lot numbers.

The 2nd round of testing commenced and the results were quite a bit different than the first test. In fact one thing that I do remember is that the "hottest" primer tested was the CCI 200 a non magnum primer. This resulted in the test being scrapped and the first test not being published.

I have found now that I have simplified my reloading to just what I now use and no changes for the most part, if I find a primer I like, I'll buy a couple thousand with the same lot number. Nothing scientific, but it is the way that after many years of searching for the special primer and powder, that I now do things.

[tn_junk]

Appreciate the input.
I pretty much use Winchester for my small rifle primers (loading .357 MAX) and CCI for everything else.
It just gets a little confusing when different sources suggest different primers. You explanation of the primer vs. powder burn rate helps me understand it.

Thanks

alan

[victorcharlie]

I found the link showing high speed photographs of different primers burning

http://www.6mmbr.com/PrimerPix.html