Question about 1903 springfield Rockwell

[cplstevennorton]

I read the case study of the heat treament a little more. In 1937 someone from the Philly Depot traveled to the Pennsgove Labrotories of the Dupont company to do extensive tests of how to fix the hard/brittle receivers with heat treament. They did the draw back process on several hard low number receivers till they were in the 35-40 Rockwell C test range.

They then explain the normal pressure of a M1 round of the time was 50,000. SA tested them with a high pressure round of 68,000 when they were proof fired at SA.

After the hard low number recievers went through the draw back process. They loaded rounds in the 60,000, 80,000, 90,000 and 100,000 range. And planned to fired them at each interval to see if they survived.

All low numbers went through the drawback process were able to withstand up to the 90,000 round, but all but one slightly cracked at 100,000. One was able to witstand the 100,000 round.

For a control comparison they tested normal High numbers receivers. Ones that had nothing done to them, but were high numbers considered safe. It says all high numbers shattered badly at the 90,000 round, except one. It shattered badly at 100,000.

It's interesting to note that they make specific mentions that the low numbers "Slightly cracked" and the High numbers "shattered badly" at the extreme pressures.

It then says in 1938, that the Philly Depot started to explore this option as well, in house, and did have successfully tests of "drawn back" low number receivers that could withstand the 100,000 pressure round.

At the end of the case study they conclude there were issues with both low and high numbers that were failing the rockwell C test, and they should rockwell test and re-heat all receivers that failed the test, both lows and highs.

But like I said, if my memory serves right, they didn't do it long. Maybe a year, and discontinued it. I just don't rememember what was their reason they stopped. It might not have worked in the end. I just can't honeslty remember. But I thought you might be interested in this additional info from the report.

[Flying10uk]

I was taught by an old school tool maker, while leaning the trade myself, that when you harden steel you should always then immediately reheat to to the correct temperature/time etc to give the required amount of temper to whatever you are heat treating. You should always follow the hardening with the tempering operation as soon as possible and avoid any unnecessary delay in the 2nd operation of the process, i.e. the tempering. It was explained to me that any delay between the 2 operations will tend to make the steel brittle and likely to fracture even when it has been subsequently correctly tempered. This kind of information is not likely to be found in text books. I guess a similar thing is likely to occur hear if the receiver wasn't tempered as much as it should have been originally, over time the receiver may well have gone brittle; no amount of further tempering today is likely to correct this.

[pickax]

Thanks for looking further Steve, I have a 1938 dated SA barrel with 368K Rock Island receiver with the dimple from Philly that you helped ID as a Marine rifle.
I would suspect time elapsed and budget was a factor in discontinuing their efforts. Interesting to hear about the drawback process though.

[firstflabn]

Unfortunately, nothing fixes burnt steel. A Rockwell test will not reveal its presence. Also, a proof test is an imperfect predictor of receiver behavior in a case head failure.

Until the above is understood, along with some of the whys, any discussion of safety is a waste of time. 'Tis a puzzlement that some will draw conclusions about the physics without having at least read Hatcher's account.

[Flying10uk]

Another possible cause of the problems with the Springfield receivers is that they may have been heated to too high a temperature in the initial hardening process. In my experience of heat treatment of tool steels if you get this first part of the hardening process wrong the job is normally scrap and you may as well bin the it and start again. If the steel is significantly overheated over what is recommended there is little that can be done to salvage the job. Different types of steel have differing ranges of temperatures that they need to be heated to to harden them; you need to get it hot enough but not too hot.

[CINDERS]

At least if your going to play with a suspected handgrenade action do it by remote control in a booth where fragmentation if it occurs will not bother any one may want to some how film the results I would keep the stock or at least put it into a real knackered one. Hatcher had some interesting experiences I must get to grips with that book its been sitting about 3' away from me for months have only graze read it also with his book on the Garand same same. Manns The bullets flight is an interesting book also had a good read of that one and these 2 of Whelen's

[Chuckindenver]

to keep this simple.
many have looked real deep into this issue,, more so looking for a feel good answer or a cheering section.
facts.
SHT actions are harder then double heat treat and Nickle steel actions.

they dont fail out of the blue.. out at the range, and boom...or just let loose.

its how the steel handles a simple case head failure. and they usually dont,

were as a DHT or NS action has a better chance of surviving a simple case head failure.
without getting to deep, and kicking a dead horse.. thats the deal in a nutshell.
so, a hardness test would likely not prove anything more then whats already been tested hundreds of times..