I thought the loose powder was supposed to be hotter than the pellets?

couple of months ago took my Omega and M700 out to make sure they were still sighted in. My M700 (musket nipple) was shooting with a slight delay in the ignition, don't know if my nipples were too weak or if it was the powder. Then while shooting my Omega I ran out of the loose 777 so I grabbed some 777 pellets that were in my bag. FYI was shooting 110g of loose. Load with two 50g pellets and it shot with more noticeable kick, louder sharper "crack" and grouped 1.5-2" higher.

Any ideas on what's going on? Bad powder maybe?