It is prudent to back off then work back up when going to a mag primer, but I have to admit that I have not seen a signinficant increase in pressure signs or velocity when making the change.

Accuracy is a different story. I don't know what they do to match primers, but I have found them to shoot much more accurately in all of my loads (hunting and match loads).

Deke.

Generally speaking, the biggest difference in "magnum" primers and "standard" primers is the price.



Some brand's "standard" primers may be "hotter" than other brand's "magnum" primers.



In cases the size you are loading and with the powders you would use in those calibers, there would be no advantage in a "hotter" primer, whether it is labeled "standard" or "magnum".



The largest case volume that I have loaded for is a .338 on an 8mm Remington Magnum case. The slowest powder that I use regularly is WC 872 (slower than H870) in a .264 Winchester and a 7mm STW. None of these combinations require "magnum" primers for uniform and reliable ignition. Since I do have some "magnum" primers in stock, I tend to use them on the "big boys", but neither chronograph nor target results show a measurable difference.



In theory, if you switched from the mildest primer (likely a CCI 200) to the hottest (likely a Federal 215) in a small case like a .22-250 loaded with a near-maximum load, then you might see pressures rise enough to be undesireable, though not likely dangerous.



Another generality, though certainly not a universal truth, is that milder primers tend to provide better accuracy. That is one reason that benchresters sometimes use brass made with small-size primer pockets for calibers that normally use a large primer.



If you're looking to demonstrate differences in accuracy due to primers alone, considering the number of brands and the number of different primers offered within brands, you'd shoot out your barrel before you had enough data to draw any reliable conclusion.

My primer selection process consists of a very in-depth analysis that's based on color: I like silver ones. That means CCI or Federal, with a leaning toward the Federal 210.



RSY

The scientific process I use to decide which ones to use consists of which I can buy for less than $20/1000. Its the science of $$.
Otherwise I haven't ever had any one show me convincing proof there were good ones opposed to bad ones. Although when I use CCI BR-4 they seem to burn very clean and leave little if any pocket residue.....

I haven't found that, generally speaking, they make a lot of difference. But sometimes they do. In his reloading pages, Steve Ricciardelli, for one, tells about a 25-06 that he couldn't get to shoot well until he switched primers, and then it became very accurate.



Go to this URL:



http://www.stevespages.com/table1.html



And then go to the 25-06 story #1 for his account.



My own shooting tests suggest that, unless you really need the magnum primer to ignite a large amount of powder (I use them in my .300 Weatherby, for example, but NOT in my .375 H&H), non-magnum ones often tend to give better accuracy.

Quote "was wondering if I should incorporate experimenting with different brands of primers when searching for the load that likes my rifle the best?"



Only you can answer that question. Enroute to your personal answer, you need to ask a couple of other questions: 1.) How accurate does your best load shoot now? 2.) Is that accurate enough for the uses to which you put your rifle?



If you decide you need more accuracy, and want to know if changing primers will increase your accuracy, the answer is "Maybe".



In 1968, when I lived in Edmonton, I used to shoot at the Sherwood Park Range (which then was little more than a bare field hacked out of a bluff of small trees with a berm at one end). One day there I ran onto a newly immigrated Yank who was having the Devil's own time trying to get good groups from his new .340 Weatherby rifle.



Even in those days I had owned a chronograph for more than 10 years, so I fired it up and chrono'd half-a-dozen rounds of his then-current handload. The chrono showed slightly over 200 fps extreme spread, from slowest to fastest of those 6 rounds.



I took him back to my home in the Garneau District, and we trekked down into the basement to work up something which might shoot better. What we loaded was exactly the same load he had been using at the range, except instead of CCI Magnum primers, we used RWS primers. Then, back to the range, where we did some more chronographing. Extreme spread was just under 35 fps with the RWS primers and groups were just under an inch...markedly better than before.



So, that makes it sound like primers can really have an efect, eh? The answer is still "Maybe".



With my own .30-BR and .30-PPC benchrest guns, I use any one of 3 different primers, depending on which is the handiest at the moment. They are the F-205-M, WSR, and Remington 7-1/2-BR. I MAY occasionaly get a flyer from the 7-1/2-BRs that I don't get from the other two, but not often enough to be convinced of it. Otherwise, all 3 are completely interchangeable with the same powder and bullets, for the same accuracy.



So, if you do need more accuracy, all I can say is "give diffferent primers a try." Maybe the difference will be significant. Then again, maybe it won't be.



Best wishes,



Alberta Canuck

The process that I use is quite simple. My short action cartridges, .243, .260... use Fed 210s, the 06 based cartridges use Win. WLR's and the ones that hold over 70grs of powder get Fed.215's. Also any cartridge that uses ball powder gets a 215.

In all loads I develop the last thing I do is switch to every primer I have to see what effect, if any, they have on group size.

I always start off with Federal 210M's in all but ball powders where I use 215M's. In 75% or so of primer switches there is no change in accuracy and very little in velocity. In about 10% of cases the accuracy deteriorates. In the remainder, accuracy noticeably improves, mostly at random as between makes of primers, but usually Winchester primers are the usual ones to noticeably improve. In most instances the standard 210M's give better velocity than magnum primers. At one point or another, other primers have been preferred, including Remington 9�M's and CCI250's. Not much luck with the standard ones in those manufacturers.

About all you can do is switch them and find out if there is any difference. It could be an exercise in futility, and then again you might end up with that group with all in one hole!

without primers gun dont go bang.

I keep three different primers on hand at all times. Fed 210M, CCI BR-2, and WLR. After I have developed a load and it is shooting as good as it can with the primer I developed the load with. I try the other 2 primers to see if it helps any. Sometimes it does and some times it don't. I have reloaded for 30+ years and I have learned which which primers have worked best with which powders. I have always had the best luck with the Fed. 210M with the VithaVouri powders, CCI BR-2 primers have always given the best results with H4350 EXT in my 260 and 308. With IMR 4064 in my 308 there just isn't any difference between the the two behind 155 Palma MatchKing. The WLR is the only non match grade primer that I use. I have had pretty good luck with it and RL-15 in a 308. In my 233 I have nothing better than the Rem. 7 1/2 BR primer regardless of the powder I used. So yes I do think primers make a difference.

RiverRat

Anyone found any difference between the Federal 215 LR mag primers and the CCI LR mag 250 primers? I have both and will begin loading in a 340 Weatherby to see which producest the best results.