Priming compound for rimfire vs. percussion cap

[alcestwo]

Went to the range earlier in the week to shoot my muzzle loader a couple of times. Guy at the bench next to me was banging away with an MSR that, looking at the ejected brass, looked to be chambered in .22 WMR. As I set up, I realized I had forgotten my percussion caps. Sitting there for a moment before packing up, I wondered how similar the priming compound is for modern rimfire cartridges to the modern percussion caps (#10 or #11). Any thoughts? Just wondering out of curiosity. Pulling the head on a couple of .22s to have as insurance against the next snafu isn't really a good option.

 

[Caveman]

Fundamentally I would think not much difference. But I can imagine the actual formulas and burn rates and overall design are different. the rimfire only has a small amount of compound around the inside of the rim. where as the cap has it all across the bottom. That’s what allows it to fire into the nipple which also acts as the anvil to ignite it. The rimfire wouldn’t likely fire as the anvil doesn’t exist in this scenario there is nothing to pinch the rim of the case and if it did the way i’m envisioning it. The nipple would actually seal the igniting compound outside of the fire channel. I could be totally off base. just what i’m picturing with this scenario.

 

[MisterHappy]