Mag vs non mag primers

[Bedrok]

7MM WSM. 61gr IMR4350. Can anyone tell me why Federal NON magnum primer’s average 40fps faster than Federal magnum primers?

 

[6.5 forever]

I've seen similar differences in the past. Every lot will vary. Magnum and standard primers.

 

[RegionRat]

Sometimes what we call a magnum primer only means the primer cup specification takes higher pressure.
Sometimes what we call a magnum primer means the brisance (primer charge) is higher as well.

For some reason, the industry doesn't really make their primer specifications or performance clear.

 

[joshb]

Yup. I found the same thing with magnum large pistol primers.

 

[Bedrok]

Thanks guys. I guess I never did a head to head comparison.

 

[6.5 forever]

Thanks guys. I guess I never did a head to head comparison.

It could be worse. Next try a lot to lot test of the same primer
Lol

 

[Texas Solo]

All I know it's that my ES and SD got smaller when I switched from CCI400 to Cci450

 

[Bill Norris]

All I know it's that my ES and SD got smaller when I switched from CCI400 to Cci450

In my experience the 400 and BR-4 is good in smaller case powder capacity but when using larger case powder capacity the 450M gives much better E S & S D #s

 

[Big Mc]

Sometimes what we call a magnum primer only means the primer cup specification takes higher pressure.
Sometimes what we call a magnum primer means the brisance (primer charge) is higher as well.

For some reason, the industry doesn't really make their primer specifications or performance clear.

YUP

 

[Fire Dog]

CCI 450’s is all my 6BR likes and performs better than the BR-4’s for much less cost…
As mentioned above, often the “magnum” primers have a tougher cup to withstand higher pressure and “usually” have a higher brisance to ignite the larger amount of powder associated with “Magnum” cartridges.
Saying that, all things vary from lot to lot and testing a new lot may result in having to slightly modify a load but usually not by much.

 

[243winxb]

Federal magnum primers

consumes more powder at lower pressure. The burn time is less & less powder may exit the barrel.
IMR 4350 has no nitro

https://discover.dtic.mil/

 

[Fire Dog]

IMR 4350 has no nitro making it a lot easier on the chamber throat…
Nitro powder {double based powder} has its place and in the big end of competition, barrels are just another consumable… Just like the powder, primers & brass.

 

[Coyotefurharvester]

I think the primers(mag vs standard) change how quickly the bullet leaves the case neck, try a light crimp on a few rounds with mag primers and see if you gain a bit of velocity. A short fat case would make the difference more noticeable.