OK. new info. This apparently is a model LK becuz of the rounded receiver. The folks at Knight rifles( 866-518-4181) said that the original hammer with the conical pointed firing pin is ok to use with the #11 and musket caps. I won't pierce a primer, which was my concern. but you must have the # 900023 breech plug with 1/4x28 nipples. This has been quite an adventure trying to find the parts to convert this back to #11 caps. If I didn't like the gun so much, I would have given up and traded it. But I think the effort will be worth it next season. I have a 54 cal hawken, but I like this gun becuz it is weatherproof for the late season hunts we get here in Idaho. The rules were written for the Idaho fish and game by members of the local black powder club, and they are 100% primitive weapon only. They didn't even want inlines at first, but had to relent. No sabots, jacketed bullets, powder pellets. optics, 209 primers, enclosed caps in breech, etc. BTW. the folks at Knight rifles were very helpful. It took a while to get thru, but they resolved my questions. They apologized for the wait, but said they have been swamped with calls. If anyone wants this 209 breech plug, PM me and we can do a deal. I think this needs the FPJs to work, but I am not sure. It is in great shape.