The following is a post by Frank Green of Bartlien Barrels. It echos my opinion.


I see two possible topics here and will touch on one for now.

The c.m. that we spec. and buy is not harder than the 416 SS. Most of it is 30Rc. The mill has a range and it will vary a little bit in the stuff we get. It can vary a couple of points either way but for the most part.

What other barrel makers spec. or buy for they're s.s. and how they control the quality of the material they get or any extra heat treating etc....I will not comment on.

The Melonite and cryo. Melonite is still to new and some of the other treatments being done etc....are variables we cannot control. Some say one process the c.m. steel reacts to the treatment more than s.s. etc....Cryo treating doesn't for the most part make the steel harder. If it does it's like a point or so but for the most part you don't see a change. At least being a barrel maker we haven't seen it.

The c.m. does machine a little different but that's about it. Nothing drastic to say one is easier/better than the other.

Accuracy wise I see no difference with c.m. Yes I do have S.S. barrels for the most part on my match rifles but some of my match guns and all of my hunting rifles have c.m. barrels on them. Why do I put S.S. barrels on my match guns. Don't need to put a finish on them is the main reason.

Guns like a match M14 or when I restored my '03 Springfield as a U.S.M.C. Model 1941 Sniper rifle I put c.m. barrels so they have the parkerized finish put on them. How do they shoot? The '03 has a Unertl scope on it. Timney trigger and I glass bedded the stock. How about a 1/3 moa gun and it will do it at will if you steer it right.

Most of the ammunition test barrels we make are c.m. and the data I've gotten back from ammo makers etc....I see no difference in accuracy vs. a s.s. barrel.

I would lean towards a c.m. barrel lasting longer than a S.S. They do wear differently. I cannot put an exact number on it. It's mostly gut feeling and data that we see but there are so many variables from types of powder a guy is using, what the barrels are chambered in etc....to put exact numbers on it.

A few years ago we made a really good bench shooter some c.m. barrels. Why because he wanted them blued to match his action and he wanted to try some c.m. barrels. First or second match out with them he won one of the bigger bench matches with them.

Also I feel the c.m. is more forgiving in manufacture and stronger in some respects vs. the s.s. My opinion here.

I have no second thoughts though about putting a c.m. barrel on one of my guns. It really comes down to though is what I'm building the gun for and how I want it to look etc....will make me decided what I'm putting on the gun.

Later, Frank
Bartlein Barrels

A very interesting read and opinion. Thank you.

It seems to me that CM barrels copper foul just a tad more than SS.

Other than that, not having to blue SS has been the reason for me to use stainless barrels on most of my latest projects.

- mike

quote:

The Melonite and cryo. Melonite is still to new and some of the other treatments being done etc....are variables we cannot control. Some say one process the c.m. steel reacts to the treatment more than s.s. etc....Cryo treating doesn't for the most part make the steel harder. If it does it's like a point or so but for the most part you don't see a change. At least being a barrel maker we haven't seen it.

The metallurgical issue here is the ability of the quench to trap the crystal structure in its form above the eutectic.

Temperature differential between the hot steel & the quench medium is part of that efficiency
BUT
High yemp differential in Cryo quench etc works very efficiently & uniformly with depth for thin sections ( think.... knife steel etc). With thicker sections like barrel steel the rate of heat exchange is determined by the conductance values of the steel itself the further you move away from contact with the quench medium.
Heat exchange in the bore of a pierced rod is poor in quenching & almost not different to a solid rod a/c lack of quench medium exchange.

A bit like the old chestnut of an aluminium can cooling the beer faster than a steel can.........it does , but its so marginal as to make no practical difference as the rate of heat exchange is determined by the fluid IN the can rather than the difference in conductance of the skin of the can materials.

No wonder the hardness values of only a point or 2 is seen in practice in the quote by the OP .

CM starts with a bit of a hardness/rigidity advantage compared to 416SS simply from its inherent alloy crystal structure.