Thank you for the photo's. Your cases are 2 3/4". Measured from the bottom of the rim to the top of the case. That is good because cases are available and would solve your priming troubles. I notice your bores are rifled with what looks like a very slow twist and very shallow rifling but your slug shows no rifling. You need to use a pure lead slug to slug a bore. If the slug you use is slightly smaller than the bore dia. you have to upset the slug to get accurate measurements. If it is slightly larger than the bore (I would recommend it as thin as those barrels are made on the end) Than you can drive the slug through. This might explain some of the measurements you have listed.