Are #41 primers hotter than #400 or is the cup thickness the only difference? I'm loading 25 gr. 8208 XBR in LC brass ,Hornady FMJBT, #41 primer. Standard trim and COL. My Sport likes them.

I have read that the CCI 41 primers are hotter and harder than CCI 400 small rifle primers. Roughly equivalent to the CCI 450 small rifle magnum primers as to power. But, that is what I have read and have no definite proof or statement from CCI.

CCI tells us they are magnum class primers. The compound used is also less sensitive.

__________________
Freedom is never free!!
SWCA #3437

Thanks guys.

CCI Ammunition - Primer Details
Mil-spec sensitivity
Initiator mix optimized for ball/spherical propellants
Available in large (No.34) and small (No. 41) rifle
Use the same data as CCI Magnum primers

The Number 41 primer is the same as the 450 magnum primer but the cup is thicker in the base requiring more force to set off the primer.

The vast majority of slam fires occur when when a single round is loaded without the magazine in the rifle to slow down bolt velocity and firing pin inertia.

Now the good news, when Remington ran Lake City the 5.56 ammo used the 7 1/2 primer that has a cup thickness of .025.