Magnum Vs Regular Primer Test

[Brian Pfleuger]

I conducted a short (scientifically invalid) test today in my 357sig.

I loaded 5 rounds with 8.1gr Power Pistol under Hornady 124gr XTPs using Federal "Match" small pistol primers and 5 rounds using the same bullets and powder charge but with Federal "Match" small pistol "Magnum" primers.

Curiously, the average velocity was indistinguishable, and very stable, right at 1400fps. The highest velocity was a non-mag primer at 1407 and the lowest was a non-mag primer at 1387. All others were between 1395 and 1405.

Oddly, 3 of the 5 magnum primers were very slightly pierced, while none of the others were.

All of the primers showed significant flattening and minor mushrooming, which is really of no consequence in this case as every load that I have tried using Federal primers has showed significantly flattened primers, even loads of 7.1gr Power Pistol which should be VERY low pressure, relatively speaking.

[kaylorinhi]

To start with I am currently reading LYMAN'S third edition Pis&Rev manual. I may get to it later in the book but this thread brings up the Question; What is the difference between the two?

Thanks Mike

[Brian Pfleuger]

Magnum primers are supposed to burn hotter and longer, making it easier to ignite hard-to-ignite powders.

As such, for any given powder, changing from a standard to a magnum primer will generally raise pressure and velocity. The "accepted" difference is generally figured to be akin to a 5 to 10% increase in powder.

I will definitely have to do some more testing. The magnum primers did exhibit less velocity deviation, but the sample size is so small that there is really no significance. However, even on a small sample, I would have expected a marked, obvious velocity difference.

[kaylorinhi]

Thanks Man

[Bamashooter]

might just be a fluke , but i get better groups with magnum primers.

[riverwalker76]

So ...here are a few question for you to chew on, and possibly a test.

~1) Will the Mag Primers be beneficial in a 9MM load where you are using Titegroup? Titegroup has been known to have failed complete ignition in certain charges. Actually, the 124 gr. XTP might be a good place to start.

~2) Are the pressures significant enough in the above said charge to reduce the load by .2 grains from the regular load?


Food for thought. I'm interested in the outcome. I've heard of a few instances where Titegroup at certain charges in the 9mm has left unfired powder inside the chamber and even on the shooter's hands.

[Brian Pfleuger]

Originally Posted by RiverWalker76

Will the Mag Primers be beneficial in a 9MM load where you are using Titegroup?

I don't know.... I'm using Power Pistol.

[Loader9]

Here's the problem with yer test as I see it. Power Pistol is not hard to ignite. I went thru numerous loads for pistols and even in the 44 mag data using PP, there are no magnum primers recommended. I would not expect there to be much difference in the results. If you have a much slower powder in a larger case, you might give that a try but I've found very few powders that have issues with normal standard primers.
The difference in the mag primers and standard is called brisance. It is the explosive properties of the primer that makes the difference. Here's the definition:
http://www.thefreedictionary.com/brisance

[Shane Tuttle]

I can't remember where I was reading, but I think you'll find differences if you compared loads with lower charges. Seemed that the material I was reading stated the magnum primered charges had more inconsistent velocity readings. Don't remember the powder, either. Could have been TiteGroup or Clays. Wonder how Power Pistol would act.

1400fps? Isn't that screaming even for .357Sig?

[Brian Pfleuger]

Originally Posted by Loader9

Here's the problem with yer test as I see it. Power Pistol is not hard to ignite. I went thru numerous loads for pistols and even in the 44 mag data using PP, there are no magnum primers recommended. I would not expect there to be much difference in the results. If you have a much slower powder in a larger case, you might give that a try but I've found very few powders that have issues with normal standard primers.
The difference in the mag primers and standard is called brisance. It is the explosive properties of the primer that makes the difference. Here's the definition:
http://www.thefreedictionary.com/brisance

Yep... that's the definition alright. They burn hotter and longer.

It seems to be pretty universally accepted that changing to magnum primers makes a difference of the equivalent of 5-10% additional powder. Sometimes, not so much. In this case, apparently not so much.

Originally Posted by Tuttle8

1400fps? Isn't that screaming even for .357Sig?

It's moving right along.... but it's a 5.3 inch barrel.

Actually, a max load of Power Pistol is approaching 1400fps even in the stock 3.46 inch barrel. Factory loads are 1300ishfps.

Using the SAAMI max of 40k PSI, Quickload predicts about 1350fps from the stock length barrel but....

CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assume any liability for any damage or injury resulting from use of this information.

Using the CIP spec of 44,237psi, Quickload predicts 1394 fps from 8.9gr of Power Pistol.

[grubbylabs]

A guy at a gun shop said that if I wanted to use magnum primers just back my load of a grain. So as a new re loader I did this and the load was really soft.

I might try them again to see if I get a more complete burn on the blue dot. I am loading it in a 45acp with a 230 grain plated HP. I do get some unburnt flakes after I shoot and it is really dirty but it is very accurate for me.

[riverwalker76]

peetza .....


Forgot to ask .... how do those 124gr. XTPs cut paper? I picked some up the other day, and am anxious to try them out?

[Brian Pfleuger]

peetza .....


Forgot to ask .... how do those 124gr. XTPs cut paper?

Sadly, I don't think that I've ever shot at a target with them. Only chronied, which is generally just into the trees. They make a mess of small trees, I can tell you that.

[Hog Buster]

Many years ago we ran the same sort of test. It’s been about 30 years so I don’t remember all the powders or loads we used. All were mid-range loads so that any small difference in velocity could be detected. We used .38 Special, 357 Magnum and .44 Magnum as our test loads. 20 or so of each loaded the same except for primers. All test rounds were fired out of the same revolvers. If I remember correctly the difference in velocity was only about 5 to 15 fps different between the Magnum primer and the Standard primer with the powders we used. The conclusion was that the Magnum primers did not add any drastic fps in velocity with these test powders.

I’m sorry that I don’t have our written findings but Hurricane Katrina washed them away.

[Hook686]

Interesting results. I tried similar experiment with .357 magnum, 158 grain SJSP, 13.5 grains of Alliant 2400 with CCI Small Pistol Primers if half and CCI Small Pistol Magnum Primers in the other half. I got consistently 30 - 50 fps higher velocity in the reloads using the magnum primers.

[Jim243]

Peetza

I would be concerned about the pearced primers, it will stress your firing pin and score the bolt face (slide). If there is no advantage, I would stick with the standard primers.

Jim

[steveno]

I tried the same thing in 41 mag using a couple of different guns with Unique and I couldn't tell the difference with standard or magnum primers. I don't shoot max loads very much so I use whatever primers I have on hand at the time.

[ScottRiqui]

I think of the primer as the "spark plug" in the ignition sequence.

In cars, if your factory spark plugs reliably ignite the air/fuel mixture (as is almost always the case with stock engines), there's nothing to be gained by going with a fatter/larger/higher-voltage spark, and the extra energy from the bigger spark doesn't significantly affect the total energy from the air/fuel explosion.

There are some cases where a bigger spark *is* needed, when the air/fuel mixture is hard to ignite (high-compression engines and large amounts of boost in forced-induction engines are two examples.) In this case, a fatter spark can help ensure combustion.

With ammunition, if a regular primer reliably ignites the powder, there's no call for a magnum primer, and unless you're already close to maximum pressures, the extra energy from the magnum primer isn't going to make much of a difference compared to the energy released from the burning powder.

[Brian Pfleuger]

Originally Posted by Jim243

Peetza

I would be concerned about the pearced primers, it will stress your firing pin and score the bolt face (slide). If there is no advantage, I would stick with the standard primers.

Yeah, I'll definitely not be using them at those charge levels. The only reason that I even have them is that they were all I could get at the time. I've only got about 75 more, so I'm going to back down a couple tenths and use 'em up. They were fine at 7.9gr.

[Lost Sheep]

Thanks for running the test. I disagree about the validity. Sample size may be small, but you controlled for variables, observed, accurately measured. That's scientific method/experimental method, right? Might not be conclusive, but is still valid observation.

http://en.wikipedia.org/wiki/Scientific_method

More formal definitions of scientific method involve forming a testable hypothesis and designing an experiment to prove/disprove the hypothesis. I think your experiment qualifies as valid.

Originally Posted by peetzakilla

I conducted a short (scientifically invalid) test today in my 357sig.

Originally, I was going to post what Loader9 and ScottRiqui said, but they beat me to it. So consider it repeated that magnum vs standard primers will make little difference (to pressure, velocity or reliability) to an easy-to-ignite loading, but will make a considerable difference in a hard-to-ignite loading.

Originally Posted by peetzakilla

Magnum primers are supposed to burn hotter and longer, making it easier to ignite hard-to-ignite powders.

As such, for any given powder, changing from a standard to a magnum primer will generally raise pressure and velocity.

It seems to be pretty universally accepted that changing to magnum primers makes a difference of the equivalent of 5-10% additional powder. Sometimes, not so much. In this case, apparently not so much.

The phrase "for any given powder" is crucial. Different powders and (possibly) different packing density of some powders in the cartridge case may make a difference.

As far as the pierced primers is concerned; I suspect the piercing is not due to high pressure, but to hard firing pin strike. I understand Federal primer cups are softer than other brands (making for reliable ignition), while (for example) CCI primers are said to be made of harder metal. If you want to continue using Federals, you might want to switch to a lighter mainspring and see if that results in fewer piercings, or try CCIs.

Again, thanks for reporting your experimental findings. God work.

Lost Sheep

[Brian Pfleuger]

Originally Posted by Lost Sheep

As far as the pierced primers is concerned; I suspect the piercing is not due to high pressure, but to hard firing pin strike. I understand Federal primer cups are softer than other brands (making for reliable ignition), while (for example) CCI primers are said to be made of harder metal. If you want to continue using Federals, you might want to switch to a lighter mainspring and see if that results in fewer piercings, or try CCIs.

I noticed after a couple of them had been loaded that a small piece of "crud" had found its way onto the primer seating arm and was putting a dent in the primers. I wondered if that would make any difference but forgot about it until just now. I suspect that the pierced primers may have been a result of that.

Regardless, I only have the federal primers because they were all I could get at the time. I have several hundred CCI primers also. I'll have to try a test using all three kinds and see what happens.

Incidentally, I also made sure that the brass was all the same and was all once fired in that particular barrel.

[Shane Tuttle]

I think Shooting Times ran an article by Lane Pierce regarding CCI primers having a harder cup compared to others such as Federal. This was, at one time, true. But he stated this was some time ago and they've since changed the makeup of the cups and are not much harder, if any at all. He mentioned it was an issue that some reloaders took and spread like wildfire. Even though CCI remedied the cup hardness, the percieved "damage" was done.

Do I personally think CCI is still made with a harder cup? I don't know. When I use them it does seem that my firing pins don't make quite the indentation as, say, Federals. But I haven't really investigated/experimented enough to draw my own conclusion.

[Brian Pfleuger]

Originally Posted by Tuttle8

Do I personally think CCI is still made with a harder cup? I don't know. When I use them it does seem that my firing pins don't make quite the indentation as, say, Federals. But I haven't really investigated/experimented enough to draw my own conclusion.

In my limited experience, I'd say there's no question that CCI primers are harder.

Two examples:

Some tumbler media found it's way onto my primer anvil, twice. I still don't know where it came from. Anyway, with the CCI primers, I can feel the "crud" on the anvil and actually hear the walnut shell crunching when I press the primer into the case. With the Federal primers the walnut shell dents/crushes the primers and I can't even feel that it's there. I only see the damage done.

Using identical loads for both CCI and Federal and then working up hotter loads with the CCI primers, I notice that the Federal primers, both magnum and non, will mushroom and flatten at even 9mm load levels in the 357sig. The CCI primers show no evidence of flattening or mushrooming at the highest loads that I have yet tried.

[ScottRiqui]

I know the CCI #41 5.56/NATO primers are pretty hard (of course, they're supposed to be - that's part of what makes them different from CCI #400 small rifle primers.)

When I was setting up my Dillon Super Swager and trying to figure out what depth to swage to, I discovered that I could re-prime crimped brass using the CCI #41 primers *without removing the crimp at all*. Of course, I don't recommend it as a regular practice, but it allowed me to be a little bit less aggressive with the swaging, knowing that the primers would still seat no matter what.

[SwampYankee]

With ammunition, if a regular primer reliably ignites the powder, there's no call for a magnum primer, and unless you're already close to maximum pressures, the extra energy from the magnum primer isn't going to make much of a difference compared to the energy released from the burning powder.

The thing is, during the peak of the primer shortage, magnum primers were often all you could get. People are generally afraid to use them- based on all the dire and nonsense warnings in reloading manuals- so they were plentiful. When you needed primers, you got what you got.

Even though there is/was "no call for them", people have/had them and wanted to use them.

I've run a trial using moderate loads of HS-6 and CCI 300 vs CCI 350 primers. A slight difference in velocity but otherwise indistinguishable. I use them exclusively in my .308 loads, .303 loads and used them from time to time in .38 special and .40. I don't like to break my guns so I never push my loads to the limit. With that caveat, I doubt too many people will notice or care that they are using magnum primers. Its a lot of hoopla over a relatively trivial issue. Be smart about what you are doing and it won't matter that you have magnum primers.