Klikitarik,
The clarity you seek is exactly what you continue to obfuscate. You exhibit your bias by saying �heavy loading the 1895.� Would you say working up and using loads within the safe operating pressure of the 30-06 is �heavy loading� the 30-06? I don�t think so. But for some reason when referring to working up and using loads within the safe operating pressure of the 45-70 in the Marlin 1895 it is proposed something disastrous will occur. It is simple and safe and the data to support it has been produced. Hodgdon currently is the only source that documents pressure barrel tested loads to 40,000 CUP for the Marlin 1895 45-70. That is enough for me, but obviously not enough for you. Other sources say they limit 45-70 loads for the Marlin 1895 to 35,000 or 40,000 CUP but do not document the pressure of those loads. The Hodgdon data suggests that that with a powder of proper burning characteristics the 350 grain bullet can be safely driven over 2000 fps in the Marlin 1895G. Without pressure testing similar loads for IMR4198, Reloder 7, Vihtavuori N133, Accurate Arms XMR-2015, ADI AR2207, IMR 3031, Norma N-200, and Norma N-201 the additional published information is not yet available. However, the Hodgdon data is repeatable and therefore valid. I get 2150 fps with that load out of my 22� barreled 1895. I�ve been shooting that rifle since 1977 and within the last ten years it has seen a steady diet of maximum loads with the 405 grain Remington JSP. I don�t consider it �heavy loading� anymore than I would consider loading a 139 grain bullet to 3150 fps in a 280 Remington Ackley Improved a �heavy� load. A maximum load within the safe operating pressure of a cartrudge/rifle combination is just that, the maximum load that can be used over the expected service life of the rifle. It is a load that allows the rifle to withstand the stress of firing and return to stasis without undue wear or affect on servicability. The hyperfear exhibited over the 45-70 by some segments of the industry and shooting community is based on a long history of complicated factors. However, the facts bear out that the safe operating pressure of the Marlin 1895 45-70 is at least 40,000 CUP and there is no more danger achieving that level than there is in reaching maximum loads for any other cartridge/rifle combination.
You have been plenty clear about your confusion over the characteristics of and potential use of 45-70 loads intended for the Marlin 1895 and the Ruger #1. First, you suggest that the Hodgdon maximum load of 54 grains of H4198 used in some rifles will reach dangerous pressure levels due to individual characteristics. This may be true, but it is the case with every other cartridge/rifle combination. You seem to be proposing that the Marlin 1895 45-70 is somehow different, I contend it is not any different than any other carrtidge/rifle combination that we use maximum load information for. All of the techniques, procedures and cautions are generally the same for the use of published maximum load data for any cartridge/rifle combination. There is nothing inherently different with the Marlin 1895 45-70. The limit developed for it is based on the same considerations that are used to develop the limits for any other cartridge/rifle combination. Second, you claim that there is some kind of pressure spike because of a change in charge not intended for the Marlin 1895 creates a larger increase in pressure. It is not unusual for relatively fast powders to exhibit larger increases in pressure as the loading density increases. To assume that that will necessarily occur at a lower loading density is not correct no matter the individual characteristics of the rifle. It is irrelevant that the Marlin 1895 is not a �good bolt action�, as pointed out before the limits developed for it are based on the same considerations as for any other cartridge/rifle combination. It is all relative, and does not suggest that the Marlin 1895 is any more prone to fail when working around maximum pressures than doing the same thing with a �good bolt action.� A bolt action is certainly stronger than the Marlin 1895 but they are not necessarily designed to contain higher excess pressure. A proof load for either is a prescribed percentage of excess and does not mean the Marlin 1895 will fail sooner than the bolt action given relative increases in pressure. The cartridge case of the 45-70 certainly can indicate excessive pressure in the Marlin 1895 as well as those cartridges used in a bolt action. Extraction, case lengthening and pressure ring expansion can be just as reliable in the Marlin 1895 45-70 as extraction, primer condition and pressure ring expansion is in a bolt action.
The best tool we have in absence of pressure testing equipment to consistently work up maximum loads for any cartridge/rifle combination is the chronograph used in conjunction with published data. Velocity in excess of the published maximum velocity is a very reliable sign that one has gone too far. It is not difficult to estimate the expected velocity for loads in rifles of different barrel lengths. There are more than enough indicators that become evident in the Marlin 1895 45-70 to become aware that one might possess an exception. There are not necessarily fewer pressure signs with the Marlin 1895, but there are adequate pressure signs.
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.
This has absolutely no bearing on this discussion. Marlin is a member of SAAMI and must promote SAAMI standards. The SAAMI pressure specification for the 45-70 is based on the vast number of older weaker rifles in circulation. However, the standard does not even protect them as many older Springfield Trapdoors should not be subjected to more than 19,000 to 21,000 CUP. Marlin�s support of 28,000 PSI for the Marlin 1895 is institutional, not technical. Essentially the same rifle is industry standard loaded to over 40,000 CUP in at least two instances. There is no more decrease in safety margin loading the Marlin 1895 to 40,000 CUP than there is loading any other cartridge/rifle cartridge combination within its safe operating pressure. That argument is another of your red herrings.
I still believe many of your arguments are red herrings. They are really not relevant to the issue at hand. It is not anymore dangerous to work up to and use a published maximum load following accepted reloading practices for the Marlin 1895 45-70 than it is to do so in any other cartridge/rifle combination. The non-issue you promote is not borne out by the facts. There is sufficient information to show that the Marlin 1895G can indeed achieve 2000 fps with a 350 grain bullet, even if you refuse to believe it or believe it has to be dangerous. I don�t doubt there are many people who have pushed the Marlin 1895 over the limit and continue to do so at their peril. I remember well T/C Kid and his iterations on the Big Bore Lever Rifle forum on Marlin Talk. But anyone who follows accepted reloading practices and uses Hodgdon #27 data for the Marlin 1895 45-70 are not in that group.
Again, the potential difficulties you refer to exist for the reloading of any cartridge/rifle combination and the Marlin 1895 is not somehow inherently different or more prone to mishap than any other.
