Regarding the Lancaster smooth oval bore rifling, used for a very long time, on the smallest to the largest calibers, on both black powder rifles and nitro rifles too, I have a couple of questions, if anyone has seriously examined, and preferably measured bore(s) on any of these (I would prefer facts based on your examination; not opinion based on your thoughts only):
1. If you actually measured the bore(s) on one or more of these oval bores, or, better yet, if you took a cerrosafe mould of the bore(s), how much variation did you find between the bore and oval size (diameters)? In other words, what is diameter of the oval and what is the dia. of the bore, so one can determine difference between the two, as these essentially function similar to lands (bore), and grooves (oval)? If you did this, please tell me what caliber it was done on.
2. Did lancaster use the same depth of oval, compared to the bore dia., for both black powder rifles and nitro rifles, or did they change the oval depth making for less depth on, say, the nitro rifles?
3. Did they change the twist rate, from Black to nitro, or even from one caliber to another? If you examined twist rate on one or more of these, please tell me what the twist was, and on what caliber.
4. Finally, Have you any conclusions as to most accurate handloads for the oval bore rifling, using bullets of bore diameter, paper patched up to oval diameter, or soft pure lead bullets of oval diameter, patched or unpatched to what diameter, or what other handload did you find most accurate? If so, for what caliber did you do this on?