This is the 98 with a Springfield bolt hybrid. Friend has one that is very soft. Anyone know what they're made of, ie low carbon 4140 etc. He's thinking of having it heat treated. Thanks.

Your friend needs to locate a metallurgical lab/shop that specializes in "Optical Emission Spectroscopy". It is a non destructive method of obtaining an analysis.

I can help you some way...but maybe you know thsi already?

It is said that Parker Hale were offered cheap, at a true "give away" price a large amount of genuine Springfield '03 bolts.

Now, bolts being more expensive to make than receivers, they took them.

So the bolts are genuine American as I don't think any other nation made the Springfield '03?

The receivers Parker Hale had made. I am only making speculation and conjecture on this but I believe they may be Spanish?

In England Norman Clarke Gunsmiths near Rugby or G E Fulton at Bisley might be able to advise?

Both are long standing and respected and have long enough memories to maybe know about these things?