Primers ?

[rebs]

What is your preference in primers for 223 benchrest shooting matches at 300 yds with Varget powder, CCI BR4 or Federal gold medal match 205M?

 

[M-61]

What has worked well for you so far?

 

[6.5 forever]

Maybe try anything you can get to start with.

 

[JimPag]

What has worked well for you so far?

Whatever works best in the load you have developed. Some primers work better than others that's why you should have a good amount of different primers to experiment with.

 

[6.5 forever]

And it does vary lot to lot. I found CCI 450 to be more accurate than BR4
, but slower.

 

[Conaso]

And it does vary lot to lot. I found CCI 450 to be more accurate than BR4
, but slower.

I'm surprised with the lower velocity, CCI 450 is supposed to be SRP-Magnum, while BR4 is the same as 400 - only better QC. Some say 450 offered better consistency at lower cost than BR4, IMHO - I believe that was just a good lot but several reported same conclusions. I saw a report someone posted about using different primers, with one exception CCI was better; CCI 400 was slightly better than BR4 and velocity was nearly the same. Go figure.

 

[6.5 forever]

I'm surprised with the lower velocity, CCI 450 is supposed to be SRP-Magnum, while BR4 is the same as 400 - only better QC. Some say 450 offered better consistency at lower cost than BR4, IMHO - I believe that was just a good lot but several reported same conclusions. I saw a report someone posted about using different primers, with one exception CCI was better; CCI 400 was slightly better than BR4 and velocity was nearly the same. Go figure.

The key is lot to lot differences.

 

[drop_point]

I'm surprised with the lower velocity, CCI 450 is supposed to be SRP-Magnum, while BR4 is the same as 400 - only better QC. Some say 450 offered better consistency at lower cost than BR4, IMHO - I believe that was just a good lot but several reported same conclusions. I saw a report someone posted about using different primers, with one exception CCI was better; CCI 400 was slightly better than BR4 and velocity was nearly the same. Go figure.

I was under the impression that BR4s are closer in dimension and performance to 450s than 400s.

 

[Conaso]

I was under the impression that BR4s are closer in dimension and performance to 450s than 400s.

Dimensions - yes. Brisance - no.

Very similar to CCI’s standard small primer (CCI 400), but with a slightly thicker cup (.025″ instead of .020″) and stamped “Benchrest” to indicate it is “match quality.”

Per 4/17/2023 email from Cody B., CCI Technical Service Representative – “The CCI BR4 have an equivalent ignition rate to a CCI 400.”

I wish CCI would have left posted the info on their primers like they had years ago.

 

[rebs]

what about Federal gold metal match small rifle primers ?

 

[JFrank]

This may help clairify

 

[LCazador]

Thanks for posting that chart JFrank. As you can see there is a difference in cup thickness between the BR4 and 205M. With that said since you may be shooting heavy bullets at higher pressure for your discipline I would opt for the BR4's over the 205M's. Testing the hotter 450 primer would also be an option. BTW I've been using the primer dimension chart above since the first time I saw it in 1995.

 

[Conaso]

I'm surprised with the lower velocity, CCI 450 is supposed to be SRP-Magnum, while BR4 is the same as 400 - only better QC. Some say 450 offered better consistency at lower cost than BR4, IMHO - I believe that was just a good lot but several reported same conclusions. I saw a report someone posted about using different primers, with one exception CCI was better; CCI 400 was slightly better than BR4 and velocity was nearly the same. Go figure.

This is the report I recently found. Only 4 shots each, but

Primer Comparison Testing with 6 BRA at 500 Yards « Daily Bulletin

Here is a very interesting test for the 6 BRA (6mmBR Ackley) cartridge. Forum member James Phillips, a talented long-range benchrest shooter, tested SIX different primer types from three different manufacturers.

bulletin.accurateshooter.com

It appears he used the same load. So, contrary to what I have read and seen, I was surprised with the CCI that the 450M did not have a faster MV.

The CCI 400 has the best group size, ES, and SD. (Never with me!)

All CCI velocities were only within 3FPS.

Primer Brand	Group Size	Velocity	Extreme Spread	Std Deviation
Remington	7.51.985″	2955 FPS	8 FPS	4.0 FPS
Federal 205M	2.200″	2951 FPS	11 FPS	4.8 FPS
Sellier Bellot SR	1.673″	2950 FPS	14 FPS	5.9 FPS
CCI 450M	2.341″	2947 FPS	14 FPS	6.6 FPS
CCI 400	1.253″	2950 FPS	3 FPS	1.3 FPS
CCI BR4	1.275″	2949 FPS	15 FPS	6.9 FPS

 

[djporter]

What is your preference in primers for 223 benchrest shooting matches at 300 yds with Varget powder, CCI BR4 or Federal gold medal match 205M?

450’s

 

[searcher]

What is your preference in primers for 223 benchrest shooting matches at 300 yds with Varget powder, CCI BR4 or Federal gold medal match 205M?

I'd use whichever one gives you a measurable difference in improvement. They are both up to the job. Sometimes, that can be hard to see on just a few groups, though, especially if you do minimal brass prep. Those "smaller" cartridges can tend to throw out some pretty crazy ES's without anal brass prep. But within 300 yards, it doesn't always equate to less accuracy as much as might be expected. The heavier the bullet and the hotter the load, the more I might be inclined towards the 450's - but the Federal Gold Medal Match can trump all in terms of accuracy as often as not. The difference in velocity with that load would not likely exceed 40 FPS one way or the other between the two primers in the .223. Sometimes the difference is just enough to put you into a better node or maybe pull you to the outer edge of what was a good one.

 

[drop_point]

Dimensions - yes. Brisance - no.

Very similar to CCI’s standard small primer (CCI 400), but with a slightly thicker cup (.025″ instead of .020″) and stamped “Benchrest” to indicate it is “match quality.”

Per 4/17/2023 email from Cody B., CCI Technical Service Representative – “The CCI BR4 have an equivalent ignition rate to a CCI 400.”

I wish CCI would have left posted the info on their primers like they had years ago.

While you may have been quoted something true by CCI, the results in my barrels is what I’m talking about. Running them in my .308 and 6.5 Creedmoor, ES and MV are nearly identical between the 450 and the BR-4. The 400, ES and SD are larger, but MV is down about 15 fps with the same powder charge. I don’t know about measured ignition rates because I do not have the ability to test that, but I can use a chronograph.

 

[Conaso]

While you may have been quoted something true by CCI, the results in my barrels is what I’m talking about. Running them in my .308 and 6.5 Creedmoor, ES and MV are nearly identical between the 450 and the BR-4. The 400, ES and SD are larger, but MV is down about 15 fps with the same powder charge. I don’t know about measured ignition rates because I do not have the ability to test that, but I can use a chronograph.

I don't disagree, truth is downrange at the target with 'that' firearm. That posted report just threw out what I thought I knew when I looked at the CCI velocities and ED/SD.

 

[Dimner]

So when is the right time to test primers? And what is the right metric to look at?

It seems like testing primers after a load has been tuned as good as it is going to get would be a crap shoot in how group size results would come out.

Has anyone every done a full tune with lets say three different primers? And if you have, what kind of powder or seating depth differences did you notice?

 

[Shifty6br]

Been using for many many years 450's with any extruded/stick and Rem 7.5 for all spherical/ ball powders. The cartridges I load for are all mostly br variants with 6mm being the largest

Always seemed to work out with great results. I've always been a kinda leave it alone guy so for me why ruin a good thing I guess.

 

[padom]

205Ms