CCI or win. primer

[Johnnn01]

Going to be loading some 40s&w with 165gn and bullseye and have a recipe that calls for cci primers, is there a big difference if I use win primers?

[johngalt]

It depends on how close to max you are. I load primarily light target loads, so I interchange primers all the time and don't worry about any slight differences. I prefer Federal when I can find them though.

If switching between standard and magnum primers, there may be a difference, but I still have my doubts. I can't remember where I read it, but I thought someone here loaded some .357 (or was it .38 special?), same powder charge and bullet and only changed between standard and magnum. According to the chronograph, negligible difference. Don't take my memory as gospel though.

In any case, how would you decide if you were over pressure? Flattened primers? Primers don't indicate anything at pistol-level pressures.

IMHO, if you are so close to the edge that a primer change pushes you over, you are already too hot.

[Collo Rosso]

I don't have the experience most here do but I haven't been able to tell a difference between brands of primers, never mind standard and magnum.
I have loaded Winchester, CCI, Federal, Wolf and Tula primers with every one of them going bang. Biggest difference I see is how they seat in the primer pocket.

[MichiganScott]

I use CCI and WW standard primers interchangeably. Never noticed a difference in performance.

[M3Stuart]

What he said ^^^^^

[ageingstudent]

I haven't had any issues switching primers either. I usually start with CCI and then try winchester or remington as I develop the load. I never change primers near the max load without dropping back some and working back to max. I have noticed some performance improvement in certain loads by just changing primers. Especially true in rifle calibers.

With high pressure type calibers like the .40 S&W I think it's probably prudent to back off a max load some with a primer substitution and do at least a mini workup.

[ageingstudent]

Originally Posted by johngalt

In any case, how would you decide if you were over pressure? Flattened primers? Primers don't indicate anything at pistol-level pressures.

IMHO, if you are so close to the edge that a primer change pushes you over, you are already too hot.

Yeah a chrony might help to spot it but it still seems that any velocity difference would be small. Might be a fun test to try actually.

[ArchAngelCD]

I use mostly CCI or Winchester primers and I interchange them without altering the loads. Of course the popular wisdom is to back off the charge weights and work back up when you change any component in the recipe. Those 2 brands are my favorite.

[Jboutfishn]

My perception is seating is more consistent with Winchester Primers.

[Shield9 Pro]

I have used both Winchester and cci primers in the .40 before. And I will say this you should reduce you load and work up of course. Also if you have a lightened firing pin spring that may been part of a trigger job. cci primers are harder to set off and could cause a miss fire issue the brass Winchester are softer and have performed every time for my self.

[scooter123]

It's my understanding that there is a sort of Gentlemen's agreement between the manufacturers to keep the energy produced for each type close enough to not cause issues or changes in measured results. Because of this we can interchange primers between brands without a change in the measured ballistics. At most there may be a small change in the accuracy of a particular load but in a handgun you would need to use a pistol vice to observe the difference.

IMO the reason it's reported in the load recipe is simply because it's proper Scientific Method to record and report everything. I expect that if we could see the original test reports that not only brand and type of primer was recorded so was the temperature, barometric pressure, and humidity.

However, because there is only a Gentlemen's Agreement in place it is common sense to start over when the brand of primer is changed. Having done that between Federal and CCI primers I can report there wasn't any change in the final loads that I could measure using my Shooting Chrony chronograph. I can also report that the primers that have caused issues in my tuned revolvers were those in Remington UMC 250 paks, not CCI primers.

[H Richard]

As long as you stay within "standard primer" all the same and "magnum primer" all the same I don't see enough difference to notice in handgun loads. But with rifle loads, and shooting bench rest groups, you may be able to notice a difference. For my long range loads I never substitute when I normally use the Federal 210 M bench rest primer.

[retired_diver]

Originally Posted by johngalt

In any case, how would you decide if you were over pressure? Flattened primers? Primers don't indicate anything at pistol-level pressures.

In my experience they do. I have had flatten primers in both 44 mag and 357 mag. I was using what many call the hot reloading manual, ie Speer #10. After the primers flatten, I backed off the load 3 tenths of a grain to play it safe. Yes they were revolvers not pistols, but IMO pistol primers can give you valuable info in working "hot" loads.

[fredj338]

When working a load to max, everything matters. So if you switch primers, drop 5% & work it back up. If you are starting from scratch, you are still working the load up to max for YOUR gun, so primers don't matter. If your loads never get close to the top end, primer brand wont matter.

[fredj338]

Originally Posted by ageingstudent

Yeah a chrony might help to spot it but it still seems that any velocity difference would be small. Might be a fun test to try actually.

It totally depends on what powder/primer used & caliber loading. The 9mm & 40 are more susceptible to small changes than say the 45acp. Its an easy test for guys with chrono; load 5 of each diff primer in identical loads, same brass, powder & bullet. Some powders will show a marked increase in vel, which means pressure are up to. Others will not, it just depends.
FWIW, Win primers are marked for std or magnum, so they actually fall between other brands as to brisance or heat. Again depending on powder & caliber, it may or may not matter.

[Bkreutz]

The only difference I've observed between CCI and Winchester primers is the shoulder profile of the cup. The CCI is more rounded and is easier to load into the primer tube while the Winchesters are more squared and require a closer "aim" to get it into the tube. For those of you who play, it's like the difference between a barroom pool table and a snooker table.

[chief38]

The only problem I have with Winchester primers is cosmetic. I do not like their Brass color - I much prefer Nickel. That said, I still use them ( they seem to be the least expensive these days ) and they do work fine.

When it comes to Primers for target Shooting and Plinking I'll use any of the Winchesters, Remingtons, Federals or CCI's - whatever is the least expensive or what I can get at the time. My brand of choice (all things being equal) has been Federal. The only thing I hate about them is that they come in a huge "shoebox"!

[johngalt]

Originally Posted by Bkreutz

The only difference I've observed between CCI and Winchester primers is the shoulder profile of the cup. The CCI is more rounded and is easier to load into the primer tube while the Winchesters are more squared and require a closer "aim" to get it into the tube. For those of you who play, it's like the difference between a barroom pool table and a snooker table.

I wonder if CCI primers have changed. A few years ago I got a box of 1000 SP, I had trouble seating them. They seemed more finicky, where Winchester and Federal had no issues.

[johngalt]

Originally Posted by fredj338

It totally depends on what powder/primer used & caliber loading. The 9mm & 40 are more susceptible to small changes than say the 45acp. Its an easy test for guys with chrono; load 5 of each diff primer in identical loads, same brass, powder & bullet. Some powders will show a marked increase in vel, which means pressure are up to. Others will not, it just depends.
FWIW, Win primers are marked for std or magnum, so they actually fall between other brands as to brisance or heat. Again depending on powder & caliber, it may or may not matter.

Only Winchester's Large Pistol is marked for both standard and magnum. The last time I checked anyway, they still had both SP and SPM.

[Mcwsky09]

Originally Posted by Collo Rosso

Biggest difference I see is how they seat in the primer pocket.

I have had more issues with Winchester small rifle primers than CCI small rifle getting them to seat properly the first time every time. I am using mixed brass including some range pick up - and at least one of the headstamps seems to have a primer pockets that are either slightly undersized - or slightly off center - or maybe were swaged - and the CCI primers seem to be either soft enough or tapered enough (or something) to go right in while the Winchester primers are harder or straighter or something that makes them more likely to catch on the pocket and not seat properly - although, even though I have to force them in and they look a bit odd they still go bang.

I have not used other brands (yet) and so long as I can get CCI primers for under 3¢ each including tax/delivery/hazmat - I will likely just stick to CCI across the board.

[johngalt]

Originally Posted by retired_diver

In my experience they do. I have had flatten primers in both 44 mag and 357 mag. I was using what many call the hot reloading manual, ie Speer #10. After the primers flatten, I backed off the load 3 tenths of a grain to play it safe. Yes they were revolvers not pistols, but IMO pistol primers can give you valuable info in working "hot" loads.

I certainly don't claim to be an expert, and I know that reading primers has been an accepted practice. It just doesn't make sense to me for these reasons:

* Primers flatten for reasons in addition to pressure.

* Does anyone know at what pressure a primer flattens? I've never seen any data published.

* Does every primer flatten with the same pressure? I doubt it, especially Federals which have a reputation of being soft.

* Does the pressure at which a primer flattens depend on the calibre of the cartridge it is seated in? Logic tells me no.

* Does the pressure at which a primer flattens depend on the particular firearm it is fired in? If it is in good working condition (no excessive cylinder gaps, endshake, chambers in spec, etc.) I would think the differences would be insignificant. Firearms are made to high tolerances, and they aren't much different from one to the next.

* I have many different reloading manuals, old and new. My oldest is probably Speer #6 or 7. My newest is Speer #14. I also have Hornady 7th. NONE of them say that reading primers is valid for pistol loads. Flattened primers are discussed in the rifle section, not the pistol section.

For example I used to read about checking for flattened primers in hot .38 specials. Why would a primer flatten in a 20,000 psi cartridge, but not in a .357 magnum @ 35,000 psi?

The OP's .40s&w is high pressure (for a pistol), but there are higher still, for example the .460. It has a max pressure of around 55,000 psi, and I think rifle primers are recommended. So I would assume that pistol primers have problems somewhere before 55,000 psi. Where, I don't know.

My point is, after all my rambling, I don't know the pressure at which a primer flattens, and I don't believe a cartridge will generate significantly different pressures from one firearm to the next if in proper working order. I don't accept the methodology of "work up until you see flattened primers, then back off a bit". Especially in a low pressure cartridge like a .38 special.

Others who have much more experience than I have doing it that way for a long time, but there are too many unknowns and assumptions for me.