Primers: Std. vs. Magnum

[Arapaho]

I had had great success with CCI BR4's in both my 6.5x47's using H4350 and 223's using Varget. SD's rarely run higher then 5 in my rifles.

My two exact powder choices with my 6.5x47 and 223 with br4s. 140 Berger hybrids in the 6.5 and 69 grain smk in the 223. I would like to spin up a faster twist 223 and try some 80.5 grain Bergers though. Maybe someday lol.

 

[remingtonman_25_06]

My 223 is a Ruger MKII Varmint 26" heavy barrel. It does 3775-3800fps into the mid .3s at 100 yards for 5 shots when I do my part with 28g of Benchmark and winchester cases. Its warm, but it shoots! Been playing with the 52g ELDMs and it's doing 3475-3500fps with 26g Benchmark and it shoots in the .4s.

 

[Tulsa Reiner]

Heres a chart that shows you cup thickness

Sherm: what was the source of that table? (if you have it readily available.)

 

[243winxb]

Chart/Table -From oct 1995 by James Calhoon ://www.jamescalhoon.com/primers_and_pressure.php

Drop Test- SAAMI-

A method of determining the sensitivity of primed cases held in a specified die and subjected to a range of specified firing-pin blows imparted by a freely falling ball. Commonly called Drop Test.

SENSITIVITY TEST FOR PRIMED SHELLS OR PRIMERS.

Note: Sensitivity changes from lot to lot.

 

[CobraM197]

The majority of PRS and NRL competitors use the magnum small rifle primer in the 6.5 X 47 if you lend any credence to PRB.

https://precisionrifleblog.com/2019/09/18/6x47-6-5x47-lapua-load-data/

 

[nksmfamjp]

Remember what drives small rifle primer development.....222 and smaller moderate pressure rounds.

If your 223/5.56 rounds run like mine do, they are loaded probably 50k-60k psi. 41 or 450 are appropriate. My test is to do load development with one. If I cannot get sd's as low as expected, I try another primer.

 

[Timeout]

Here is an interesting primer photo test if you have not seen it: https://www.6mmbr.com/primerpix.html
Also, piercing of primers can be eliminated by changing the diameter of your firing pin. Several rifle smiths are capable of performing this work by bushing the bolt and either grinding your pin or installing a new one. Greg Tannell of GreTan Rifles in Rifle, Colorado is one of these. "Carlsbad" who posts on Accurate Shooter forum also does this work. Both do excellent work. Bushing the bolt will also eliminate cratering of the primer.

 

[Randy Tidwell]

Here is an interesting primer photo test if you have not seen it: https://www.6mmbr.com/primerpix.html
Also, piercing of primers can be eliminated by changing the diameter of your firing pin. Several rifle smiths are capable of performing this work by bushing the bolt and either grinding your pin or installing a new one. Greg Tannell of GreTan Rifles in Rifle, Colorado is one of these. "Carlsbad" who posts on Accurate Shooter forum also does this work. Both do excellent work. Bushing the bolt will also eliminate cratering of the primer.

I have seen a couple of the guys eliminate primer piercing by bushing the bolt and grinding the pin. Those guys were only getting pierced primers on occasion, I was getting them allot. I had the 6Dasher Panda bushing, still pierced them.

The XP has 4 barrels (6BR, 6Dasher, 30BR, & 308Win), only one that has pierced primers is the Dasher.

If it was happening with just one gun, I would agree, bush the bolt. In my case it didn't help.

I really like the Wolf primer, works for me.

Just my 2 cents worth.

 

[GLTaylor]

Thank you! That was the "brisance" test I mentioned a while back. Pretty remarkable how much primers vary in their flash

 

[Timeout]

I have seen a couple of the guys eliminate primer piercing by bushing the bolt and grinding the pin. Those guys were only getting pierced primers on occasion, I was getting them allot. I had the 6Dasher Panda bushing, still pierced them.

The XP has 4 barrels (6BR, 6Dasher, 30BR, & 308Win), only one that has pierced primers is the Dasher.

If it was happening with just one gun, I would agree, bush the bolt. In my case it didn't help.

I really like the Wolf primer, works for me.

Just my 2 cents worth.

I have heard that the Wolf primer is good. I shoot Dashers quite a bit with no issues. My first primer piercing was a straight BR. I would be interested in what Dasher loads you have had piercing problems with. I shoot a fairly good charge of Reloader 15 in my 700 Rem hunting Dasher.

 

[Savage 12BVSS]

But ultimately, only TESTING leads to best primer for your system.

This has been my experience exactly, try the primers with the powder and load you are using and the rifle/ES will tell you what it likes. When I finish load work-up I now test six different brand and type primers. You would be surprised how different the same load shoots with differing ignition.

 

[L.Sherm]

Absolutely misleading, there is a difference in the mix and you do not want to interchange

Absolutely not misleading, if you read my earlier post I said CCI is the only one that claims magnum SR primer. Rem and Fed claim match.
You never swap primers without lowering load no matter magnum or not and I never suggested any different.thinner cup primers are for hornet based cartridges because they run lower pressures.

 

[Tech4]

I am using Lapua with SR mag 450 with SR I couldn't get the velocity I was looking for and accuracy AD were better as well.

 

[Slibey]

One way to find out your best load that not near pressure and do a least 5 each. Then go shoot them over a crony. Compadre pressure velocity groups ect then you,ll know