A few years ago, Pa. had some very cold weather during the after Christmas flintlock season. I always leave my rifles outside when hunting during very cold weather. When I left the house one morning, the thermometer read -15. I remember wondering if my flintlock would fire reliably at that temperature.
I didn't have long to wait (fortunately),I shot a doe and my flintlock went off almost as fast as a modern rifle.
If your pin hits that 209 primer, it will fire.