BR vs ST. VS M

[ceard]

I saw on another forum that BR (benchrest) primers are hotter than standards and are the equivalent of magnum primers. IE CCI large rifle BRs' are the same as CCI large magnum rifle primers.
I couldn't find any data to substantiate this. Does anyone have a link to data available? It would be good to know as I have a decent amount of small rifle BR primers I bought in a lot of stuff a couple years back.

 

[Mikecr]

I don't know of any source for useful information about primer differences.
We have no way to measure primer differences, nor our striking attributes.
It's hard to say that primer swapping is useful to find one better than another.

It's painful for me to say it, but for now we're probably ok to just use what we have, as long as we powder develop with it.

 

[FEENIX]

I saw on another forum that BR (benchrest) primers are hotter than standards and are the equivalent of magnum primers. IE CCI large rifle BRs' are the same as CCI large magnum rifle primers.
I couldn't find any data to substantiate this. Does anyone have a link to data available? It would be good to know as I have a decent amount of small rifle BR primers I bought in a lot of stuff a couple years back.

When in doubt, go directly to the source and ask CCI.

 

[Mark37082]

I have read many threads on primer differences in cup thickness and brisance. It always seems we want something we can't find. I am starting to feel like if it goes bang consistently, then develop a load with it and go shoot.

 

[FireFlyFishing]

I've never heard the BR primers are hotter. Claimed to be more consistent. CCI #34 are the same as CCI 250s though. Not sure about the #41 primers whether they're hotter or not.

 

[wldcat]

I was always told Cci br primers are equivalent to standard non magnums, just more consistent I guess. Would be curious to hear what the actual truth is.

 

[martinakl]

It's called "primer brisance." If you google that, you can find some charts.

For example, I found this: Hot to cold (top to bottom). This kind of suggests BR's are on the lower half of the chart vs. the upper half.

BUT, context matters. If someone said CCI BR2's are hotter than CCI 200's.... Maybe that's true. BUT, not as hot or hotter the Fed 215 and the next five down the list.

Freaking context man. Broad, definitive statements are often/always wrong. That is some test taking 101 for you there.

To answer your specific example, seems like there is a decent gap between CCI 250 and BR2's.

 

[Mikecr]

Just sayin: until we can measure primer attributes ourselves, there is no reason to believe anything from anyone.

The reason I hold this notion is because primer makers have utterly failed to provide the following information:
1. optimum striking
2. optimum seating
3. optimum flash hole
4. model per capacity

I'm pretty sure primer makers do not know these things. That they know only as much as we do.
And so, it's on us to find out (if ever).
Otherwise, it's hearsay, anecdotal, clan lore, sales brochures, and abstract nonsense.

 

[ceard]

I did email CCI a few days ago and have not heard back. The word I was missing in my search for info was brisance. Once I started typing that in, I was able to find all kind of test having been performed on a large range of primers. The BRs seem to be definitively slightly above CCI 200s with a much lower standard deviation. Worth noting that the I saw a couple of charts that where tested velocity and accuracy using the primers as the changing variable and the BR-2s did not always come out with the lowest standard deviation in those tests. Which brings up even more questions and outcomes that I rabbit holed down for a while.
I work in development, (not firearms the industry unfortunately) so my job is basically fixing problems that may or may not exist to make it "better". And we have been slow at work this week and I have had time to start researching some of this as I want to get back into reloading this year. I have realized that what I did before was pretty basic even if I did some load development, I pretty much stuck with a handful of powders most of the time (XBR, Lever, 4350) and primers where whatever I had.

But thankyou to all for the info I'm glad I asked and didn't just jump to some tests just to waste components.

 

[Varmint Hunter]

Both Federal and CCI will tell you that the only difference between their regular primers and their "Benchrest" or "Match" primers is that the BR or math primers are made by their most experienced employees who actually do that work. This should result in a bit more consistency.