A couple of years back, I traded for a Remington Rolling Block receiver, which I believe to be a No. 5 receiver. When I received it, there was a 6" piece of the barrel still attached (the chamber end). When I checked its bore, it was .284 leading me to believe it was an Old Spanish 7mm or 7 X 57. This receiver is in EXCELLENT condition, showing no pitting or ill effects to the untrained eye.
I purchased a new full octagon 34" heavy .458 barrel from Badger Barrels. I sent the gun to a highly recommended gunsmith who is currently completing the project. Will be chambered for .45/70. New barrel, forearm and butt stock from Treebone Carving, trigger work, mounting a 32" long, fixed 6 power Wm. Malcolm scope, bluing, etc. pretty much the whole works on a basic, not to get fancy budget job.
Once it arrives, I will post some pictures.
I went to my old copy of the Hodgdon's 2006 Annual Reloading Manual (the paperback magazine issue) and opening to page 86 I found load data with pressure numbers for the 7 X 57. I averaged the listed pressure for all 59 loads, which came out to be 45,737 CUP. Knowing that the receiver was designed for this pressure level, is there a major difference in going from a "bottleneck" to a straight wall cartridge as far as pressure is concerned. What about the "thrust" that comes back on the block, hammer and the pins that holds everything together?
I enjoy long range shooting with real big boolits (500 - 550 grains) and would like to reduce the arch as much as possible. That is one of the main reasons for this project. Knowing that most try to keep "Trapdoor" loads below 28,500 to 29,000 CUP in pressure and that most "Lever Actions" loads are usually kept around or below the 35,000 CUP level, does anyone have any EXPERIENCE with a set up like this who could tell me what might be a safe maximum load.
I had hopes of being able to shoot some loads in the 35,000-CUP range, but first of all SAFETY IS THE NAME OF THE GAME.
Any feedback from those with experience and or gunsmiths would be deeply appreciated. I have been reloading for over 25 years and would like to be able to load for another 25 years.
Thank you in advance for any feedback.