Ignition on 777 pellets with CCIm primer failed

New here. And my first muzzleloader. Getting ready for Wisconsin MZ deer season. At the range trying different load combinations in my new TC Impact SB 50 cal. had a strange experience. Started with BH209 and the CCIm 209 primers and switched to 777 pellets which then misfired using the CCIm primer. I understand they are hotter than the Win 209s for muzzleloaders so expected them to be at least as effective as the Win 209 primers. The pellets showed the fire from the primer had gone through both pellets without detonating the charge. No moisture in the chamber and the breach plug was clear. Switched back to the Win 209 primer and fired the gun. Does not make sense to me. Anybody know why? A one time fluke?

Try flipping the pellets around, end for end and trying again. The last time I shot any kind of a pellet I think one end was primed with a coat of thinner powder that was much easier to ignite. And I think the primed end was always facing up in the carton they came in. Pretty sure this was T7 pellets but may have been Pyro pellets. If memory serves me right the primed end is real black as compared to the rest of the pellet. I know I had all sorts of headaches with T7 pellets until someone set me right and it wasn't until I shot regular, non-muzzlerloader specific, shotgun primers that occasional hang or mis-fires were almost eliminated. Never had a mis-fire in the Impact with 209 powder, and like you can hunt in some really cold weather here in MN.

Personally in the Impact I'd stick with the 209 powder. My Impact was a pellet gun for some time and I fought the crud ring the whole while. As soon as I switched to 209 the ring was a no-show and my groups tightened up substantially. I've shot 3/4" cloverleafs of five shots at 100 yards with the Impact, 209 and 77 grains [weighed][110 grains by volume] using 300 grain .44 cal XTP bullets in smooth black sabots. I never saw that sort of accuracy with T7 pellets, or loose powder in T7 for that matter. Pyrodex was worse.

How old are the T7 pellets? They don't keep well an draw moisture.
Pyrodex pellets have a black powder ring on one end for better ignition. T7 pellets don't have this ring.