BR2 primers vs standard large rifle

[3DGearGuy]

So, what's the difference? What makes the CCI BR2 more suited for accuracy vs the regular large rifle? It seems like a primer is a primer and as long as it goes bang, one is good as the other, no?

Oh, and if anyone in the SFV or LA area can sell me 100 of them to try out, I'd really appreciate it.


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[Fjold]

They control the amount of priming compound in the BR primers to higher standards which results in more consistent ignition. Consistency is the key to repeatability.

I did a test about 15 years ago using the best loads that I had developed for three different rifles. I loaded batches of the same ammo but changed only the primers. I tested CCI, Winchester and Federal large rifle primers along with Federal Gold Medal and CCI benchrest primers.

I shot these for group size at 200 yards but also over my chronograph to look for velocity variations.

Just from memory the most consistent regular primers in group size and standard deviation (velocity variation) were the CCIs but the CCI benchrest were about 8% better in group size and 8 fps better in Standard deviation the Federal premiums 10-12% better in group size and around 10 fps better in SD.

I wish I could find my notes from this, it was over 150 rounds fired in each of three rifles. Three 10 shot strings with each of the different primers. I realize that a larger sample size would probably yield better data but it was enough information for me.

About 7-8 years ago I did a similar experiment using large rifle magnum primers in my 375 H&H. I tried Remington, CCI and Federal magnum rifle primers but the accumulated recoil affected the group sizes so much I had to throw out the group size data. The Remington magnum primers had the best velocity consistency by a large margin though.

[Grunt81]

Thanks for the info Fjold.

OP, you can feel confident in whichever primers you choose to go bang, keeping in mind Winchester LRPs and Federal 210s are perhaps the softest. I've seen Winchester primers pierce and disable a firing pin where most any other primer would have been fine or slightly flattened.

In order for you to even see the difference a bench rest, match large rifle primer makes, you really need to be doing a bunch of other things in brass prep and bullet seating to make the most concentric ammo possible, as well as shoot them from a tack driving rig to begin with. If you're like me and use Lee dies with Lake City brass in a budget-friendly hunting rifle like my Savage 11, you probably won't notice any difference in accuracy.

I will say though, IMO proper brass prep and uniform bullet seating in and of themselves, do far more for accuracy than any super expensive match primer can. I've gotten consistent hits at 1,000 with a .308 Savage rifle, Lake City brass, and Lee dies. It is my belief that flash hole and primer pocket uniforming, as well as thorough full-length sizing do volumes for uniform brass prep. The way I prep my brass, I get an extreme spread in weight of 2.5 grains over a batch of 100 LC cases sorted by year and fully prepped.

[Grunt81]

By the way, I read somewhere on the internet that a guy actually called Federal and asked them this same question. What's the difference between the 210 and the 210M? The Federal representative simply responded by saying the 210M go through ONE more step of quality control

[rdfact]

Thanks for the info Fjold.

OP, you can feel confident in whichever primers you choose to go bang, keeping in mind Winchester LRPs and Federal 210s are perhaps the softest. I've seen Winchester primers pierce and disable a firing pin where most any other primer would have been fine or slightly flattened.

In order for you to even see the difference a bench rest, match large rifle primer makes, you really need to be doing a bunch of other things in brass prep and bullet seating to make the most concentric ammo possible, as well as shoot them from a tack driving rig to begin with. If you're like me and use Lee dies with Lake City brass in a budget-friendly hunting rifle like my Savage 11, you probably won't notice any difference in accuracy.

I will say though, IMO proper brass prep and uniform bullet seating in and of themselves, do far more for accuracy than any super expensive match primer can. I've gotten consistent hits at 1,000 with a .308 Savage rifle, Lake City brass, and Lee dies. It is my belief that flash hole and primer pocket uniforming, as well as through full-length sizing do volumes for uniform brass prep. The way I prep my brass, I get an extreme spread in weight of 2.5 grains over a batch of 100 LC cases sorted by year and fully prepped.

So do you full-length size every time? No fire-forming and neck sizing only?

[klewan]

Speer reloading manual said the best employees worked on the Bench Rest line. Try some of the Tula or Wolf primers, the target shooters seem to like them, David Tubbs for example.

[Grunt81]

I have to go out of the town and the wife is begging me to go pack, but I'll give a thorough response in about a week.

Chuckhawk did a little accuracy experiment between various stages of brass prep which is not all that detailed. He prefers neck sizing. I couldn't find the other study, that is way more detailed, which concluded that full length sizing gives more uniform case dimensions. This guy was really thorough and even tested partial full length sizing. He measured shoulder angle, base, neck tension and made a bunch of charts. Gotta go but I'll follow up when I get back.

[3DGearGuy]

So the only real difference is consistency.... And the regular CCI primers are pretty consistent as it is?


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[Spanky8601]

http://www.jamescalhoon.com/primers_and_pressure.php

http://www.sksboards.com/smf/index.php?PHPSESSID=2680267622fda400f518f383ee58da3b&topic=56422.0

Here are a couple of articles that might help in understanding. But, after I read them I had to keep scratching my head.

[bsumoba]

So do you full-length size every time? No fire-forming and neck sizing only?

FL sizing is now widely regarded as the way to go. most benchrest and precision guys FL size. Without getting into the details, there is just more consistency in FL sizing than neck sizing only. Although you might get more brass life from neck sizing only, the benefit of brass life doesn't come close to the consistency precision guys need/want. Keep in mind that the FL sizing is minimal, bumping the shoulder back 0.005-0015" and resizing the body about 0.001-0.002".

Bushing dies or custom dies are also important in getting the right neck diameter and to more closely match your chamber dimensions.