Duane and a couple of others asked me to post my findings in regards to re-heat
treating an FN Mauser commercial action. I spoke to Jim at Pacific Metallurgical and he said that they could do it, but that he would need a .5"x.5" piece of an action so that they could confirm if it was 4140. He said that they would test with a spectrometer(sp).

I am wondering if it would be correct to assume that the bolt and receiver are the same alloy. If this was the case I could provide a blot handle for testing. If not then I guess I am stuck because I can't imagine too many smiths have a chunk of an FN the care to donate.

Any ideas?

When considering something as critical as heat treating, never assume the receiver and the bolt are of the same material. It is better to have the actual pieces analyzed, separately.

The process is called 'Optical Emission Spectroscopy'. To do the test, a very small area of the receiver is ground flat and placed against some type of spark device that is flooded with argon while a series of rapid sparks play over the area. A sample of the surface is evaporated which emits light (photons) and is recorded by an Optical Spectrometer, which, after calibration, provides an elemental analysis of the sample.

The area that is ground flat is small and can be done on the underside of the action, out of sight. The test area has a slightly frosted appearance that can easily be polished out, or, blended. There is a company here is Salt Lake City that specializes in this field. Give them a call and talk with them about any concerns you may have.

American Metallurgical Services
50 W Louise Ave
South Salt Lake, UT 84115
(801) 484-1777

Westpac

I had thought about asking them if they could test from the top of the (unaltered)tang as I like to thin the tang anyway. I will ask them if they can do the underside of the action instead.


Thanks for the info. I had figured that it would be more destructive than what you described.

Thanks,

Jason,
Forgive my butting in but I have a question since I am building a 7x57 on a 1951 FN. Are you heat treating the FN because you are building a rifle utilizing a higher pressure cartridge than was original chambered for the action? Or is there another reason to heat treat? Thanks.

quote:

Originally posted by bwanamrm:
Jason,
Forgive my butting in but I have a question since I am building a 7x57 on a 1951 FN. Are you heat treating the FN because you are building a rifle utilizing a higher pressure cartridge than was original chambered for the action? Or is there another reason to heat treat? Thanks.

To answer your question: I really don't believe that any of the FNs, such as the 1951, generally need to be heat treated.

Allen Day mentioned a few years ago that he had seen two brand new, in the white, FN that had lug setback. It was believed that proof loads caused the setback. I think Allen may have said that these actions were in the shop of his favorite gunsmith.

Others have mentioned FN actions that were too hard or too soft. Someone posted a photo of an FN bolt with a cracked lug(believed to be caused by a too hard bolt).

Anyway, I have a few FNs(mostly 1951s) and the cost to have them all brought up to snuff would be around 15 each. I doubt any of them need it, but it seems like cheap insurance.

But if you are having SD build your 7X57 you could ask him if he thinks it might need it. My guess is that he would just chuckle and shake his head.

quote:

Are you heat treating the FN because you are building a rifle utilizing a higher pressure cartridge than was original chambered for the action?

I already have two in 375 H&H and I might have one of my actions done up as a 416 Rem.

And my old bang around 375 has a 1951 FN action(barreled by Sako). It has taken about fifteen head of African game including 3 of the big five. I don't think I will mess with that one.

Thanks Jason.

Did anyone ever have an FN checked to see what steel was used?

I received a message from an extremely knowledgeable rifle builder. He said that the FN actions are NOT made form 4140. He also mentioned that they were not thru hardened like M70s or m700s.

He mentioned that the soft FN that he ran into was "very" soft, something like 10 RC.

Well, did he say what they were made from?

Any comments about the ones used by Sears and Wards for their Rifles?

quote:

Originally posted by 22WRF:
Well, did he say what they were made from?

Any comments about the ones used by Sears and Wards for their Rifles?

Yeah, they're the same as the ones FN sold themselves.

quote:

Originally posted by 22WRF:
Well, did he say what they were made from?

He said that he would cheak to see if he had the material specs and would get back to me. He did mention that the were high in vanadium(sp). I will forward the specs if I get them.

quote:

Any comments about the ones used by Sears and Wards for their Rifles?

I guess I left out a VERY important tid-bit.... He said the soft action was brand-new, in-the-white.

He also mentioned that he had an FN(I assume it was not one of the NIB in-the-white ones) that sheared the bolt lugs. I guess the load was hot. He said the bolt looked very hard(60 RC) and the receiver was undamaged. He replaced the bolt and it has been fine since then.

z1r is correct in that they are the same actions. The difference is that (some of) the NIB in-the-white actions were not heat-treated.

Someone just recently posted a nice photo of a couple of Phil Shoemaker's rifles. One of them looked like it was made from a commercial FN action. I think I will post on there and ask if Phil knows whether his gunmaker had that action heat treated. (reason I am concerned is I am about to spend some considerable cash upgrading an FN (Sears Model 50) action, and I would like to know whether or not I need to get it heat treated first).

Early Commercial FN's were sometimes plauged by overly hard bolts. There are some telltale signs to look for that may indicate a potentially problematic bolt.

As to in the white actions not being heat treated, I doubt that. I have one in the shop now and it is every bit as hard as the dozen or so others I have. I won't say it couldn't happen but if you think about it why would FN ever sell actions to others knowing that they will build working rifles out of them without first heat treating them. Even in the good old 50's that was a lawsuit waiting to happen. A while back there were some un-finished FN actions that required machining and heat treating.

Just my 2 cents.

quote:

Originally posted by 22WRF:
Someone just recently posted a nice photo of a couple of Phil Shoemaker's rifles. One of them looked like it was made from a commercial FN action. I think I will post on there and ask if Phil knows whether his gunmaker had that action heat treated. (reason I am concerned is I am about to spend some considerable cash upgrading an FN (Sears Model 50) action, and I would like to know whether or not I need to get it heat treated first).

FN receivers have a Brinell ball indent on the side of the recoil lug on the right side of the action.

until recent times, NO mauser actions were made of 4140 .. 4140, in 1951, was an expensive high tech, ferric, alloy.

"in the white"/unfired is subjective... and MAKES NO DARN SENSE. It had to be barreled to be proofed, and had to be fired to be proofed .. what it was, without a doubt, was an FN action that was put together and fired with "proof" loads, of some UNKNOWN but astronomical load, and then never finished..

Could there have been exceptions to FNs being heat treated? certainly, though not what they are known for.

However, if you want to know what an FN is made of, offer that gun shop 50 bucks for the receiver, chop it up, and send it to 3 assay houses.

quote:

However, if you want to know what an FN is made of, offer that gun shop 50 bucks for the receiver, chop it up, and send it to 3 assay houses.

I misquoted the guy who quoted the smith. It was a 1909 argentine that had setback form proof loads.

The FN was a "new" action, as in not from a rifle, sold as an action only. Was it proofed? Who knows, but at 10 RC I doubt it or it would have shown setback.

After getting it back due to setback the builder machined the seats and had it heat treated and it never came back.

Just to clarify, I did not say ALL in-the-white FNs were soft. I only said that it "seems" that all the soft FNs have happened to be "new" in-the-white actions.

The smith that informed me is the top builder of bolt action hunting rifles. He is a no BS type of guy and I don't doubt a word of what he has said.

quote:

Originally posted by z1r:
Early Commercial FN's were sometimes plauged by overly hard bolts. There are some telltale signs to look for that may indicate a potentially problematic bolt.

Mike
Please share what to look for in an overly hard bolt.

Mr. Shoemaker is not a smith, but he know his stuff. Here is what he had to say about his Lon Paul built 30-06, and FNs in general:

quote:

No he did not have it heat treated. I have used the rifle with heavy loads for years and as there was no set back.
I don't know it for a fact but believe that most of the problems that occurred with FN actions were most likely with the ones that were offered in-the-white. Many of those were even advertised as "not heat treated". The ones used by Sako, Weatherby, FN, Husqvarna, Browning, JC Higgens, Marlin, et al, all seemed to be well treated.


"The whole problem with the world is that fools & fanatics are always so certain of themselves, and wiser people so full of doubt" Bertrand Russell

Phil Shoemaker www.grizzlyskinsofalaska.com

This is what I am coming to believe after conversing with some knowledgeable people.

As I said, a while back there were many unfinished FN receivers being sold. They required machining and heat treating but to the best of my knowledge they were sold as such. What happened after the wholsalers sold them is anybody's guess.

Also, bear in mind that there were a good many Spanish made receivers that were unscrupulously sold as FN's. Many of these were sold in the white too.

In my experience FN actions tend,, on the whole to be no different than most other late model 98's. Most will be good, some too soft, and a few too hard.

quote:

Originally posted by z1r:
Early Commercial FN's were sometimes plauged by overly hard bolts. There are some telltale signs to look for that may indicate a potentially problematic bolt.

Mike
Would you be able to share how a guy could tell if the bolt was too hard?