Logcutter,
Thanks for the info on that. While I know that can be useful I would like to see the credible published sources for some of these 2000+ fps Guide Gun loads for the 45-70. I realize that the same loads developed in a smaller case (450) will likely show less pressure and velocity out of the slightly larger case (45-70). Can it be done without extrapolating? In other words, is there published data that reflects similar possibilities? As you undoubtedly know reading pressure signs at 40,000 is not that same as reading them at higher pressures so knowing before you get far beyond that point seems prudent.
Jackfish,
While you might believe that I am �grasping at straws� that is not my intention. I would just like to get some clarity since the issue (heavy loading the 1895) seems to be fairly common. If this is indeed as simple and safe as some make it out to be including, I think, yourself, then data should be relatively easy to produce. I am aware of the Hodgdon data you quote. That is the same source I quoted in my initial post at the top of this thread. I have gone over this before but I�m not sure you�re getting at what I�m saying in regard to that load. Maybe I haven�t been clear on this point so I�ll try again. Hodgdon lists, as you and I have both quoted, 54.0 grains MAXIMUM of H4198 for 39,X00 CUPs in the 1895. They also show a MAXIMUM load for the Ruger #1 of 56.0 grains same powder, same primer, same case, same bullet, same OAL, same barrel length, but those additional two grains show an increase of pressure up to 50,000 cup in the Ruger rifle. I AM NOT suggesting that that might be a useful load for the Marlin. All I�m saying is that it appears to be a load which could easily be very close to a sharp pressure curve increase. In some guns that pressure may spike at a somewhat lesser loading than the 54.0 grain maximum while others may take more. Since the Marlin rifle is not as strong as a good bolt action it is not possible by an ordinary means I am aware of to tell if you have reached or gone beyond the pressures published there. True, people load the 30-06 and many other higher pressure cartridges in stronger guns right up to the maximums listed but those stronger guns can contain higher excess pressures than can the Marlin. The cartridge case itself and other factors warn of excesses at the higher pressures that cannot be known at excessive lesser pressures that a Marlin might be subject to.
As I�m sure you know, the advice in any good handloading manual is to work a load up watching for signs which might indicate pressures beyond what is acceptable. While most published loads seem to be fine in most rifles, there are exceptions. Those acceptions are rare enough that it is tempting to assume that the manuals are intentionally conservative for various reasons. Yet, if you have ever had a gun that has, for some reason, been intolerant of normal published loads you will look at this issue quite differently I�m sure. Since there are fewer pressure signs at the lower pressures that the Marlin can safely contain the need for solid data is very important in my opinion. This is reinforced by the fact that loading to 40,000 cups is considerably over the 28,000 cups approved by the manufacterer of the gun. And while the gun does have a widely accepted reputation for strength greater than 28,000 cups the higher levels do obviously decrease the safety margin which the gun can contain over and above the higher limit.
The issue is not nearly as difficult to understand as it is to try to explain. You have, for the most part, been a decent and civil respondant to my queries and I appreciate that. It does seem, however, that you are trying to avoid the issue to some extent. I do believe you know those aren�t �red herring� as you call them. I believe this issue is real. While maybe not impossible, I am not convinced that the 2000+ velocities are easily obtained in the 18 1/2� barreled Marlin 45-70. There is an apparent dearth of data to support it anyway. And I suspect that the gun is frequently abused by those who attempt to do it without doing their homework. I was hoping you or someone else might produce sources for more than the single published load which I already have (and has the potential difficulties previously outlined.)
Logcutter,
Thanks for that last data as well. Would you mind revealing the source?
