Primer question

W

Wendyj

New member
I'm buying whatever primers I can find as the stores don't carry a great deal here. I started out using Winchester large rifle primers. All I could find. Then it was cci 200. Also all I could find. For past 2 months I've mixed Winchester and cci br2 primers in Remington and Hornady brass. I can't see any shifts or changes in poi. For my 7 mag I've used Rem 9.5 primers and cci mag primers.
Is there a significance other than the cci primers being harder or am I missing something. All my load manuals suggest Remington primers but other than the 2 boxes I found for the magnum I've never seen any here. Even if I bought a thousand on line the haz mat fee isn't worth it to me. Unless I'm losing accuracy from something I don't know. Also FYI I'm not using mag primers in anything but magnum rifle.
 
The load data tells you what primer the load developer used. With a different primer it may or may not behave any differently.

In 2006, Charles Petty did an article on primers for .223 using a 55 grain Hornady V-max and Reloader 10X powder and got a velocity spread of 3150 to 3300 fps changing only the primer from the mildest to the hottest. That's just under 5% velocity difference, but QuickLOAD shows that it takes the equivalent of about 20% increase in peak pressure to get that added velocity out of the same powder charge weight in the same case volume by changing powder burn rate. That is what changing primers did for Petty in that instance. It's just slightly more pressure than you'd get adding 5% to the powder charge. That warm primer got more of the powder burning sooner with the magnum primer, and that produced the peak pressure increase.

On the other hand, folks often report seeing little to no difference when they change primers, especially in cartridges with larger capacity that use large rifle primers, like .30-06. Sometimes they even get a lower velocity from a magnum primer.

So, what I do with primer change is reduce charge weight 5% and look at the chronograph results to see if anything has changed. Ultimately, what you want to do is use the primer that gives you the least velocity spread, as that's a good sign the ignition is consistent.

I recommend reading this short article to get some of the basics in hand.
 
Seems like you answered your own question. I have used both Remington and CCI magnum primers for the 7mm Mag and 338 mag for years without noticing any difference. Once loaded it is often difficult to tell certain bullets apart, so I use Remington which are gold colored for premium bullets, and CCI which are silver for the rest.

Yes different primers can yield different pressures, but since you should begin with a starting load whenever you change any component, you should catch any differences. Switching standard for standard or magnum for magnum has never made a significant difference in my own experience, but then I am not a bench rest shooter looking for the last couple of thousandths in my groups.
 
"...not using mag primers in anything but magnum rifle..." Magnum primers have nothing to do with magnum rifles or cartridges. They're about the powder used and sometimes the ambient temperatures. They help ignite powders in cold weather. Some powders are hard to light period so the slightly longer burn time at slightly higher temperatures of magnum primers makes a difference.
Despite what is listed on Hodgdon's site. Most of the powders given there for 7mm Mag do not require magnum primers.
In most cases, changing the primer on a hunting load does nothing to accuracy. Pressures might change, but not enough to damage anything. Just the same, conventional wisdom says if you change any one component you should work up the load again.
 
The last point is true for most, but I did have a fellow using light Garand loads in .30-06 report his Garand's accuracy improved significantly when he went to the #34 magnum primers. The reason is mentioned in that article I linked to. The magnum primer produces more gas, which helps produce adequate starting pressure when there is a lot of air space in a case. So it's a good choice when your charge produces poor case fill.
 
That was an interesting article unclenick. I'm guessing that I need the hotter flash using Reloader 22 and IMR 4831 since their burn rate is slower than the IMR 3031, Varget ext that I use in 243, 260, and 308. Like I stated earlier I don't see much difference in the smaller calibers but I am intending to try some long range work with the 260 so I am trying to stay consistent. I was getting ready to buy my first thousand instead of by the hundred and I'm leaning toward the Cci Br2.
 
CCI BR 2 and Fed 210M s are bench rest primers. My understanding is that they get a little extra scrutiny in the manufacturing process to assure additional consistency. That doesn't necessarily make them hotter than their standard counterparts. They may be, but I don't know that to be the case.
 
I don't know about hotter but I have had about 5 Winchester primers that didn't go off. Not one failure in cci 200 or the Br-2. That was back when I first started loading and it could have been something I did. I will be using my 260 pretty much exclusively at the bench. Depending on what it does with these Hornady 129 ssts I'm loading now. It's hammering 140 Sierra Match Kings in .023at a hundred. Going to use 243 for coyotes and 308 ,7 mag and 444 for hunting. I'm more concerned about the bench use of the 260. Well, I can't say me because husband will use 7 mag and 444. I'm a little recoil shy to use those 2.
 
I'm accustomed to using the Fed210M s when shooting at paper but locally the supply has played out. I'm now trying the CCI BR 2 s in my 6.5 CM. Too early yet to pronounce a result but I suspect they'll do, albeit at a higher price.
 
I've read that the Winchester LR primers tend to be among the hotter primers. Hotter than some magnum. That is all I use simply because they are usually easier to find locally and I've had good results with them. I did buy 500 CCI's a few years ago when I was running low and that was all I could find. Haven't used any since I did eventually find a good supply of Winchesters.

I load for 308, 30-06, and 300 WSM. I started loading the 300 with CCI magnum primers, but on a whim loaded a few with the standard Winchester primers and noted no difference in accuracy or speed. I've since simplified my life and only use one primer for everything.
 
That would be great Jimro. Buying by the thousand would save me some money. The br2s were plentiful 2 weeks ago but it took me 3 months to find any. They charge me $6.95 for a 100 if they break box open. I can get them for $46.00 for a thousand. They seem consistent in the 260 using Rem brass. I had some Federal ammo and just threw the winchesters I had left in them. I bought a box of factory in nickel brass I guess. Can these be reloaded? Federal 140 power shoks I think. Just wanted for the brass but didn't realize it was nickel.
 
There is nothing magical about load data. It is empirical. What you see is what the testers got that day, at that time, with the equipment and supplies they note. Change any parameter and the results will change. I doubt a small change in most parameters is no big deal, but one has to be careful and aware that any changes in parameters will indeed result in changed results. Some good, some neutral, some not so good. Be careful out there. Get a good reloading manual and read about primers ... like the use of magnum primers Vs standard primers, as some powders specify the use of magnum primers. Some powders specify based upon temperature. My advice is to do a little reading.
 
You must log in or register to reply here.
Back
Top