Why would you want to know the " brisance " of a shotgun shell primer? Just about everyone understands the Fed 209A and CCI 209M are " hot " primers and all the rest are pretty much the same, or, "mild".
Paul that is not true in all cases. As explained different powders react differently with different primers.
In the loads Stan is looking for, of which I don't have any for Cheddites, but these loads are right from Hodgdon's site and it shows that the Federal 209A's are not giving more fps or PSI.
I have found the same in 12 ga. using Titewad powder.
12.6 LilGun Winchester 209 Remington SP410 1200 11,600
12.9 LilGun Federal 209A Remington SP410 1200 10,900
12.9 LilGun Federal 209A WAA41* 1200 11,200
12.9 LilGun Winchester 209 WAA41* 1200 11,500
These loads are using Remington STS in 2 1/2" length with 1/2 oz. shot.
