It's kind of interesting that Hornady, who has been credited by some (Hodgdon and others) as giving the unofficial approval of strength (40,000 cups) to the modern 1895 Marlin 45-70, is now getting called into question on whether any of their loads actually get there. To quote the Hornady handbook, volume 1, sixth edition, for the 1895 Marlin: �Pressures here are held to 40,000 c.u.p. maximum.� They don�t say for certain, probably with some good reason which or even if any of the listed loads actually get there (40,000 cup). However, it would seem silly for anyone to suggest that they might and then quote only loads that were much less. It would hardly be the best light in which to showcase their product(s). It would also seem silly for Hodgdon to credit Hornady for recognizing that limit if at least some of them weren't. And whether the published loads are 40,000 or not, simply looking as some the data presented in the reviews suggests, at least, that there are more than a few folks who hot-rod this gun - or something. The last load even shows one of Hornady's own max recipes (45.3 grains IMR 4198) which gives them 1900 fps in their 22" barreled test gun while the velocity quoted is from a barrel shorter by 3 1/2." While all of the velocities shown in Midway�s reviews may be just imaginative, it would suggest at the very least that little concern is shown for issues of safety when the velocities for the short barrel exceed the velocities of the longer barrel. That, anyway, violates one of the rules that has been paraded regarding the reading of pressure with the chronograph, "Stop when published velocity is obtained whether or not the powder weight is identical and assuming all other things are identical." I had the Hornady manual handy; I didn't intentionally single it out but since it was available and the bullet was their's (and they seem to be regarded, at least by some, as the original publishers of 40,000 cup data), their's was the one I compared to.
I certainly think it would be foolhardy to assume that Hornady�s loads are most likely less than 40,000 cup - since they don�t actually say one way or the other - and can therefore be bumped up a bit. As I noted in my initial post Hodgdon lists their H4198 maximum loading for two different strength 45-70s and shows only two grains of powder (with the same bullet, same OAL) and a pressure difference of over 10,000 cup. That, from everything I know and have read, suggests that one is very close to a point of potential danger with the particular load components. The situation may or may not be the same for the other propellants. Nevertheless, the modern 1895 Marlin, while obviously strong, is no modernbolt action. It just doesn�t have room for the kind of carefree disregard for strength limits that some seem to suggest.
I know there are folks who are careful and responsible and others who intend to be. Then there are those who don�t know better or seem to care less. I don�t know if you can and are willing to shed additional light on the subject or not but it seems that wisdom would suggest more prudence than what some suggest.
