Condsider the fine steel of the Swiss in the early 20th century, the quality of british late 19th century steel.
Every report I have ever read of 1890’s and 1900 era steel indicates that it was of low quality. I always find statements of “slag, impurities , low metallurgical quality”. Shill gunwriters have been praising old guns for decades , but don’t confuse advertizing with quality.
The process controls of the period were primitive. The measuring equipment was rudimentary, if used, a lot of processes were evaluated by eye.
Ruger compared Mauser and Springfield bolt lug shear against that of the M77 Ruger. Mausers were made of plain carbon steel, most of the Springfields were, but don't know if they also tested nickle steel bolts. Ruger used 4140 steel. The results are in the 1969 Gun Digest assumng my recollection is correct.
My recollection was that it took 25 to 50% more force to shear the lugs off a Ruger bolt than the older bolts.
Older actions were made from plain carbon steels, they appear to have soft cores but the surface was case hardened.
This appears to be a desired characteristic of the heat treatments, to have enough ductility to withstand what is an impact loading.
I remember from a metals technology book, written in the 40’s, a discussion on plain carbon steels and the then new, National Emergency steels, which were used in the Garand and M1903A3’s. NE 8620 later became SAE 8620. With just a small percent alloy additives, 8620 had a 20% increase in yield over a plain carbon steel equivalent, and the evenness of heat treatment was much improved.
This book called plain carbon steels “shallow hardening” and material from period technical papers showed that plain carbon steels hardened erratically. From sectioned round bar stock, all heat treated same time, you could see some specimens hardened just around the surface, others were hardened all the way to the core.
So the point I am trying to make is that plain carbon steel receivers would be expected to have a high variability in properties due to erratic hardening depths. Alloy steels are much more predictable.
It would take computer analysis to determine how much older actions would benefit from modern steels. I would say they would be stronger and less likely to injure someone in a destructive incidents . Those plain carbon receivers fragment in overpressure incidents so you have a lot things flying around at high speed. Alloy receivers will bend and give more.
Compare the destruction level between a double charge of SR4759 powder in a modern M70 and overpressure conditions in single heat treat M1903 Springfields. The breeching on a M70 and a 03 are similar.
The guy who posted the M70 pictures was not seriously injured. Lots of people lost eyes, hand parts, went to hospital when their single heat treat 03 frag'd.
Some actions, like the rolling blocks, modern materials make the action stronger but a rolling block does not protect the shooter from gas venting. Shooter protection was not a consideration in old action design. The Mauser 98 has a lot of shooter protection features and is an outstanding action.
I have a Martini Henry, I really think it is a well designed and strong action. I would like to see a Martini Henry of modern materials with a decent trigger pull.
