Magnum Primers Required?

Ganderite

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I have been loading ammunition for about 50 years. I have been an active shooter for even longer.

I learned to load as a R &D technician working in the research labs of the ammo division of CIL. This was back in the dark ages when we were developing plastic shells, plastic wad columns and plastic tips for centerfire rifle bullets.

One of things I learned to was to be observant and to make notes. I use a log book system comprising 3 ring binders. I have a dedicated binder for 308 and 5.56 since I have so many rifles in those calibers and a dedicated binder for the popular 4 handgun calibers for the same reason.

logbook2-1.jpg


I don’t know how many different guns I load for, but it would be several hundred, I am sure. Each gun has its own tab in the binder and pages of load results.

logbook1-1.jpg


I explain all this as a way of saying I am not new at this.

I own many loading manuals and have enjoyed reading what is in them. I am proud to say that I am (or was) on a first name basis of some of the people who wrote those manuals. One thing that I have tended to ignore over the years was the note in most manuals to use magnum primers when loading ball powders. Until recently I have not had any ignition problem using standard primers. If I anticipated an issue, I used Winchester primers, because they are hotter than Federal.

I have just recently connected the dots and figured out the cause of some problems. The first problem was what I call “click-bang”. The rifle would fire every time I pulled the trigger, but I would hear the firing pin hit and then the bang. Good training to perfect your follow-through… This problem appears when loading a lighter bullet (150 gr in 308 and 8mm) with a Start load of ball powder and a standard primer. This is a load I make a lot of as plinking ammo.

For the last two years I have had a problem in CQB which took a long time to figure out. My rifle would jam with a bullet stuck in the throat and powder dumped in the action. The primer is firing but not igniting the powder. The pressure of the primer blows the bullet out of the case and a quarter inch into the throat. I am lucky the bullet did not go any farther, because in CQB I am in a hurry to fire the next shot. Not a good idea with a bullet stuck in the barrel…

This ammo was loaded with Remington standard primers, Wolf standards and Winchester. The powder is old military surplus similar to BLC2.

The CCI Small Rifle looks like this:

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Whereas the CCI Small Rifle Magnum:

CCI450.jpg


I switched over to the CCI small rifle magnum primer (#450) and no more misfires. The books are right. For reliable ignition, ball powder needs a hotter primer.

Once the problem was identified, it was easy to fix. Except I have about 1,000 rounds already loaded with standard primers. I can’t really use it for just practice, because spilled powder in the action is a mess that takes time to clean up. So I bought a Lee Factory Crimp die (never used one before) and crimped a few hundred of my old rounds and tried them at the last CQB. Every one went bang. So the extra pressure created by the increased neck tension was enough to ensure ignition.

This die will be installed in the last position of my Dillon and future 223 rounds will get the magnum primer plus the neck crimp.

My conclusion and advice: When making ammo that is important to go bang (competition or hunting) use a magnum primer with ball powder – just like the loading manual specifies.
 
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Sure, Now you tell me after I loaded 3500 9mm....... lol.. actually it seems I light loaded all those rounds as my 1911 doesn't lock back all the time. My glock stove pipes every 4 rounds. Arg is all I can say.
 
Well, I've only been reloading for 6 years, I did learn that lesson early on though, The CCI 450 Mag primer is fantastic.

Two good lessons here, the mag primers and keeping good notes! Thanks for sharing.
 
Always learn a lot from Ganderites posts.

I use BLC2 (ball powder) in 223 and 308 a fair bit. I sometimes shoot below -10 centigrade. I never use magnum primers but I keep my charges close to max in my rifles.

I think if using start loads and there is a fair bit of room for more powder in the case then magnum primers would probably give better ignition consistancy.
 
Hmm. Never had an issue lighting H335 with standard CCI 400 primers. Even when I've packed the case tight with a wooden dowel. At that point I had to crimp just to get the bullet not to pop out.

Please don't try this at home.

Btw, I like the primer spark pictures. Ever seen that with 50BMG primers? Sparks goes about 6" past the end of muzzle brake + a 39" barrel.
 
" Never had an issue lighting H335 with standard CCI 400 primers. Even when I've packed the case tight with a wooden dowel. "

A full case and a compressed case would not be a challenge to ignite with a standard primer.

The click-bangs and misfires I had were all mild loads. In the 223 I was only running 17 gr in a case that would hold 26. For Start loads, or milder, a crimp and a magnum primer improves the odds of 100% ignition.
 
The click-bangs and misfires I had were all mild loads. In the 223 I was only running 17 gr in a case that would hold 26. For Start loads, or milder, a crimp and a magnum primer improves the odds of 100% ignition.

Why would light loads have a harder time lighting? I would think (perhaps incorrectly) that with a more dense charge, the spark would have a harder time lighting the powder throughout the case whereas with a lighter charge the powder would more easily be lit.
 
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It is a question of pressure. A full case gets a lot of pressure from the primer. A half full case gets a lot less, because air compresses.

My 8mm and 308 plinker loads click-bang. (38gr) but when I go to 46 gr they shoot perfectly. Most of us load near the top end, so don't realize we are near an ignition limit.

If you shot is critical and if it is critical that your rifle is not put out of commission, use a magnum primer with a ball powder if that is what the manual says. There is a good reason for it.
 
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