Bench Rest CCI Primers

Really need more info.

If you are currently running some load that runs the ragged edge of the red line... then ~NO~ it is neither safe nor smart to simply insert another primer of any sort.

If your load is moderate, then throwing a new primer in isn't unsafe, but it may definitely alter the performance or POI of the load.
 
CCI BR primers are my usual primer
(I load for accuracy )
As started above they are a standard primer but they have a thicker cup and are made by
The more experienced people (less variation )

(The thicker cup helps prevent slamfires in some military rifles)
 
I don't believe that they are thicker is correct.

At least lit says more sensitive not less.

They do have a military line that probably is thicker.
 
I like using what is recommended CCI large rifle or CCI BR2 you won't see a difference , the same goes for Federal primers, Now if the question was magnum or standard primers you could use them in a pinch but I wouldn't make a habit of it . I have used magnum primers with my 45ACP in a pinch and didn't see a difference .
 
CCI military sensitivity spec (less sensitive than commercial) #34 and #41 primers do not have thicker cups. CCI told me over the phone those primers have cups and priming compound formula and quantity identical to CCI 250 and 450 magnum rifle primers, respectively. The lower sensitivity is achieved by using an anvil whose legs have a wider included angle of spread, making them a little shorter and a little less rigid than the anvils they use in the 250's and 450's. So these are really a modified commercial primer. Actual mil-spec primers go through a lot of additional lot sample testing and are a lot more expensive, therefore. The only military sensitivity spec primer I am aware of that uses a thicker cup to reduce sensitivity is the Federal GM205MAR for 5.56 (they don't make a large rifle military sensitivity spec primer). Unlike the CCI #41, it is not a magnum primer, but rather is their 205M match primer in the thicker cup.

The CCI BR primers are, as mentioned before, simply a standard primer design executed to higher QC requirements, with selected cups and anvils and the priming mix dosage introduced with an eye to higher consistency by their most experienced primer making personnel.

CCI claims on their site:

An independent researcher identified the use of CCI Benchrest primers as one of two factors that were the most significant contributors to tiny groups.​
It may be hype, but if they are genuinely more consistent it probably isn't. It's just that for reasons of how standard deviations add up, it won't be apparent unless you are trying to tighten groups of a quarter moa or less. Also, in every situation where the combination of powder and bullet are different, you can get different results. I've read recently someone saying BR primers did the worst in his experiment. There are a lot of variables here that may not be the primer's fault, though, like different seating effort messing up the handloader's use of them, or slightly lower sensitivity than, say, a Federal primer causing a mainspring that has taken a set to fail to strike with enough energy to make a less sensitive primer fire consistently.

If your gun is not shooting under 1 moa, the component combination typically matters less than if you are, but as with all other rules about loading for accuracy I know of at least one published exception where groups went from 2 moa to 1 moa with one change to one component (outside neck turning of the brass) and have personally had flash hole deburring take loads of one powder from about 1.25 moa to 0.7 moa (but I could easily get that gun to shoot 0.7 moa with other powders without resorting to deburring).

Until you try something in your gun, nothing is certain about it.
 
According to research I did a few years ago, Remington #7 1/2 SM and 9 1/2 LR are true MilSpec.

The 7 1/2 was developed for the 5.56X45mm.

This info came from the NRA.
 
If your looking for good reliable primers benchrest is the way to go , my pay alittle more .When quality drops and problems arise switsh to another brand . For now CCI BR2 primers are excellent primers..
 
I have used tens of thousands of cci primers. I like them in many applications. In gas guns, BR primers are a waste of money. In testing BR2's in my AR-10, and BR4's in my national match 223, I saw no appreciable difference in coefficient of variation with respect to velocity.....and no difference in reliability either.

In other rifles, I found BR4 and BR2 made very modest differences in low capacity cases like 204 ruger, 223, 243...and a virtually statistically insignificant difference (depending on your confidence interval) for larger case capacities like 270 win.

So, I cant say it makes "no" difference. But I doubt anyone outside of a true bench rest competitor would really notice any improvement.
 
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"...They do have a military line that..." Are nothing more than magnum primers. Nothing military about 'em except the brilliant marketing. You don't need 'em for a semi-auto battle rifle either.
Never noticed any difference between a BR primer and a regular primer myself.
 
T. O'Heir:
"...They do have a military line that..." Are nothing more than magnum primers. Nothing military about 'em except the brilliant marketing. You don't need 'em for a semi-auto battle rifle either.
Never noticed any difference between a BR primer and a regular primer myself.

Every time this comes up you spout the same thing as to "brilliant marketing" and every time it comes up you get informed as to the change in anvil angle. I guess it's you or a more knowledgeable authority as to primers.

Ron, here are the differences in the 2 primers. So the anvil angle change is the difference, this keeps the free floating firing pins from causing slam-fires in AR style platforms. This does make it so that a light strike will have a less of a change of going off.

CCI-250............................ Magnum primer, Mag primer mix, thick cup, standard anvil.
#34/7.62MM................... Mil. Spec. primer, thick cup, magnum primer charge, angle of anvil change.




Justin M./Technical Service Rep.
2299 Snake River Ave.
Lewiston, ID 83501
Alliant/Blazer/CCI/Speer
(800)379-1732

I'll take what the above email states. When people have questions as to primers I always suggest contacting CCI as they are good about emails and phone calls.

Ron
 
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