Winchester Small Pistol Magnum Primer Question

[Bottom Gun]

It's my understanding that CCI small pistol magnum primers can be used in place of CCI small rifle primers since the cup is the same hardness.
Does anyone know if this is true with Winchester small pistol magnum primers as well?

My information comes from here. Ref note 1.

http://www.sksboards.com/smf/index.php?topic=56422.0

[Unclenick]

I wouldn't count on it. The different makers have different ideas about what cup hardness should be. An experiment would have to be done to prove it.

[Bottom Gun]

I wouldn't count on it. The different makers have different ideas about what cup hardness should be. An experiment would have to be done to prove it.

I agree an experiment would be necessary with some light to moderate loads first. They could, however, prove to be useful in a pinch.

[IMtheNRA]

That information was printed in 2009. Lots of manufacturing changes could have taken place since then.

I emailed CCI about two years ago, asking if those two primers are the same. The reply was no, they are not.

[Metal god]

I think it's the other way around , you can replace small pistol magnum primers with standard small rifle primers . I wouldn't put small pistol mag primers in a 5.56 round ever .... I have however used small rifle primers in 357 magnum loads with HS-6 and H-110 powders .

I emailed CCI about two years ago, asking if those two primers are the same. The reply was no, they are not

In what way are they not the same ? Did they say what was different ?

[hounddawg]

you can replace small pistol magnum primers with standard small rifle primers . I wouldn't put small pistol mag primers in a 5.56 round ever ..

yep, I agree

[IMtheNRA]

No, they just said they weren't the same. They did not specify what changes were made, and to which primer.

[74A95]

Originally Posted by Bottom Gun

It's my understanding that CCI small pistol magnum primers can be used in place of CCI small rifle primers since the cup is the same hardness.
Does anyone know if this is true with Winchester small pistol magnum primers as well?

My information comes from here. Ref note 1.

http://www.sksboards.com/smf/index.php?topic=56422.0

This is why you can't/shouldn't believe stuff posted on the internet/forums.

Technical questions about a product should be directed to the product manufacturer.

I suggest you do this with your current question - if you want the correct answer.

Winchester: https://winchester.com/Support/Customers/Contact-Us

CCI: https://www.cci-ammunition.com/contactus

[flyguy958]

I suspect most manufactures are in "lawyer up" mode. Doubt you will receive an answer that is not, "what they are sold as is what they are". Just my 2 cents.

[Unclenick]

I am leaning of being persuaded of the same thing, at least for CCI. I originally got the information about the sameness of CCI small pistol magnum and standard small rifle primers (CCI 550 and 400) over the phone with CCI before Vista Outdoors bought them. The lady who was answering the phones actually took the time to look at the primer drawing and the cup and anvil dimensions and the amount of which priming mix was in them and said it showed they were identical and added that, indeed, CCI employees would buy the lower-priced 400s for both purposes themselves. But when I called them about this more recently, the technician said, "no, mixing them up is playing with dynamite!" But he didn't look anything up.

I've shot enough different primers in things to know "dynamite" was in exaggeration. Indeed, the biggest performance difference I've seen was in a test Charles Petty did in 2006 of small rifle primers going from standard through magnum with many brands. This produced about a 5% span in velocity which would correspond to about a 10% change in peak pressure with a 55-grain V-max and 24 grains of Reloader 10X. SAAMI standards allow individual rounds in a ten-round average to get as much as 18% over the MAP limit, and CIP standards allow 15%, so that 10% number is within expected safe limits and is still below proof pressure (though a steady diet of such loads would accelerate throat wear).

While I thought the CCI tech was exaggerating, nonetheless, I didn't want to ignore a company warning without some proof. So I bought a bag of 38 caliber commercially molded wax bullets with the idea of making velocity comparisons for them driven by the two primers as an energy measure. I also have an analytical balance and can get the before and after weights of the sample primers to the nearest tenth of a milligram. There is just one problem: the 550 and 400 primers I have are over 20 years old. I need current production to test if it is true today, but I've had no luck finding any to buy. I still keep an eye out for them, but you all know what the primer market has been like, and I'm not going to get a second mortgage to fund the test, so I am waiting to catch some at a reasonable price.

Meanwhile, board member Hounddawg found a fairly recent (Jan 1, 2021) YouTube test of 9mm ammo loaded with CCI 550 and 400 primers from the new style boxes. It is done by a shop with an Oehler 43 on an in-house pressure gun that performed the comparison and found no significant difference in either pressure or velocity produced by two primers. The function in a pistol was the same for both. However, the guy doing the test runs only the CCI products and runs a smaller sample than I would like to see, and then makes a blanket statement about all small pistol magnum and small rifle standard primers being the same. That's going too far without testing them all.

So, I would still prefer to do my own test to get the cups and anvils' weights and deduce the expended priming mix weight to be more thorough. But at least for this particular brand, assuming the video test result holds up with a larger sample, it looks like the CCI difference in these two primes is in name only. My assumption would be that since there is now a central phone system for all the Vista brands, there is a rule handed down from corporate headquarters to cover how all technical employees are supposed to answer the primer substitution question in all their companies, regardless of primer brand. This would make some sense as developments are changing primers down the road. Federal's new Catalyst primer, for example, and other changes in primers due to environmental laws may be in the offing. Having a consistent policy rather than an array of them avoids the potential to have one group get it wrong.

Again, this is all Internet information, so don't bank your life on it being true. Run your own tests. This video shows why. When I finally find 550s and 400s of recent manufacture, I'll run my test and report the results.

[74A95]

I don't get why one would want to 'test' the different primers with a method that does NOT assess if the primer compound composition is the same.

If the question is whether the primers are the same, and what defines whether they are the same or not is the primer compound composition, then that's what you have to analyze.

You don't measure something else like wax bullet velocity and before and after weight of the primer. Neither of those measure chemical composition. Therefore, ANY conclusion you might come to based on your test would be invalid.

What you need is to get your chemistry kit and analyze the type and amount of chemicals used in the priming compound.

[Metal god]

You don't measure something else like wax bullet velocity and before and after weight of the primer. Neither of those measure chemical composition. Therefore, ANY conclusion you might come to based on your test would be invalid.

lol no it wouldn't , It would only be invalid if you were trying to test the primer compound composition haha . What if you're testing if all the primers create the same velocity or near as makes no difference . I'd think that would tell you something ??

As far as primer compound composition , Id bet dollars to donuts that is different from one manufacture to the next and I didn't even need to run a test for that

[44 AMP]

Winchester makes small pistol MAGNUM primers now???

Admittedly, I haven't been in the market for some time, I still have a good supply of stuff I bought long ago, so I don't know what is being made today, but back then, Winchester primers were for both standard and magnum loads. Same primers for both loads. Said so on the box!!

There are three things involved with primers, the physical construction of the cup, including alloy hardness, and thickness of the metal, and two things involved in the primer compound, which are the amount and the specific chemical formulation.

AND, in practical terms, the amount and formulation don't really matter (other than for informational purposes) what matters is the effect produced when fired.

How much is the difference in the pressure produced between standard and magnum primers? What is the difference in "hotness" (temp, flame duration etc). And the last thing to consider is will that difference have an effect on the gun???

We know some pistols will not reliably ignite some rifle primers. Heck, there's some specially set up pistols that will only reliably ignite certain pistol primers (Federal from what I read...)

SO, I would, if absolute necessity, use small rifle primers in place of small pistol MAGNUM primers, but not the other way around, ever.

[74A95]

Originally Posted by 44 AMP

Winchester makes small pistol MAGNUM primers now???

For decades.

[Metal god]

Yeah it’s the Winchester large pistol primers that are for both standard and magnum loads . I have a few bricks of them I bought in 2014 and 2016 . They are what I’ve been using in my new to me 629 .