CCI vs Winchester primers for signs of overpressure?

[engineer40]

2 years ago I hadn't reloaded before. Within that time now I reload for 13 different cartridges. But when I started I purchased a ton of CCI primers in Sm Rifle, Lg Rifle, Sm Pistol, and Lg Pistol.

Recently I picked up 1k Winchester primers. I shot them last night and they appear more flattened than the CCI's ever did. No other pressure signs.

I realize that primers can burn differently and could potentially be causing more pressure. But I'm also assuming that the Winchester primers might be contructed differently and just flatten out more when fired? Which may be normal for them compared to the CCI's?

Any opinions? Thanks all!

 

[AD5GB]

It's been my experience, using velocity as the common denominator since I cannot measure pressure directly, that CCI primers flatten somewhat less than others. (I've grown to really like Federal and Remington primers in this regard.) I've heard it said too that in large magnum rifle primers, Winchester is the hottest and CCI the mildest, so I try to pay attention to changes in velocity as well when switching primers, especially when I'm shooting near-max hunting loads.

 

[Barrelnut]

I believe it has to do with the brass alloy used to make the primers. Some brands have harder cups than others. I believe CCI are about the hardest.

 

[MudRunner2005]

I prefer Federal primers, but also use CCI for a lot of stuff because they're easier to find around here.

 

[North Idaho Hunter]

in my personal experiences with a few rifles running right at max pressure, when trying various primers Winchester always produced a higher pressure.

I would say that its safe to assume Winchesters are hotter then CCI.

With that said, I prefer CCI, simply because they are everywhere and I have never had issues.

 

[engineer40]

It's been my experience, using velocity as the common denominator since I cannot measure pressure directly, that CCI primers flatten somewhat less than others. (I've grown to really like Federal and Remington primers in this regard.) I've heard it said too that in large magnum rifle primers, Winchester is the hottest and CCI the mildest, so I try to pay attention to changes in velocity as well when switching primers, especially when I'm shooting near-max hunting loads.

Interesting... I was actually shooting Large Rifle Magnum primers when I noticed this.

 

[MagnumManiac]

Lucky you didn't try Fed 215 primers, they are even softer than Winchester primers.

Comparing 2-3 brands of primers appearance is futile, none flatten at the same rate.
Flattened primers are a poor indication of excessive pressure anyway, due to the reasons outlined above.
The case head will normally show signs of excessive pressure before the primer flattens, ejector marks often show up before a primer fully fills the pocket.

Cheers.
gun)

 

[FEENIX]

For what it is worth ...

 

[243winxb]

Just watch for any gas leakage between the brass and primer cup. A pin hole on the edge of the primer may be from gas leakage or a defect in the Win primer. Happens to other brands also, loose primer pockets from high pressure , when loading at/near maximum. See the Win primer album at Joe Harris's Library | Photobucket

 

[Rich Coyle]

When starting with a new cartridge I usually use Federal 215 Magnum because normally my stuff requires large primers. Once I get to the load I want I then load up five with every primer I have and check to see if the rifle prefers one over another. Sometimes the groups are cut in half by nothing but a primer change. The velocities occasionally vary as much as forty feet per second.

 

[243winxb]

Just watch for any gas leakage between the brass and primer cup. A pin hole on the edge of the primer may be from gas leakage or a defect in the Win primer. Happens to other brands also, loose primer pockets from high pressure , when loading at/near maximum. See the Win primer album at Joe Harris's Library | Photobucket

Heres a better link Primer Gas Leak Slideshow by joe1944usa | Photobucket