All three of those barrels I pictured have the integral front sight ramp characteristic of the Proof Steel barrels made for the M54 beginning in 1932.  In other words the barrels look like the '33 date barrel on Berts M54 22 Hornet.  All have the later M54/70 Style 1 barrel markings that read "Proof Steel"...

While I've seen "CMS" on early Proof Steel barrels on M70s plenty of times, this is the only Proof Steel M54/70 barrel I've seen stamped "MNS" underneath.  Which begs the question which stamp is "wrong"?  Did Winchester ever make the later M54/70 barrel pattern out of Nickel Steel, or did someone inadvertently stamp "MNS" when they meant to stamp "CMS"?

It's unusual for sure... Not important enough to resort to mass spectroscopy, just unusual.  Besides, only one of those barrels is on a gun I own and it's not the one marked "MNS"...

Thank for the help!!!

Lou

Yes, the MNS stands for Midvale Nickel Steel.  Here is an excerpt from my Winchester stamp "cheat sheet", the first number is the Winchester factory drawing number for the stamp which indicates it's usage.

So, to answer your other question, I am of the opinion that the MNS stamp coupled with the "Proof Steel" marking on the barrel is possibly an error.  Further evidence may prove me wrong though.

Best Regards,

Bert H. said
Lou,
First, the underbarrel markings were applied well before the roll marking on the exposed side of the barrel. 
My bet is that the "M.N.S" marked barrel is an incorrectly roll marked Model 54 Nickel Steel barrel.
This is of course just my opinion.
Bert
  

The "M.N.S." & "C.M.S." are hand stamps along with the other under barrel markings. So easy enough to grab the wrong stamp.

I have some of these stamps. I do need to look through my research and see what means what.

I suppose the only way to truly know is that you would have to somehow test the metal between the two stamped barrels and see how / if they differ.

Good luck with that!

Sincerely,

Maverick

First, the underbarrel markings were applied well before the roll marking on the exposed side of the barrel. 

My bet is that the "M.N.S" marked barrel is an incorrectly roll marked Model 54 Nickel Steel barrel.

This is of course just my opinion.

Bert

Since the discussion has turned to barrel steel, I'll ask a question...  

The M54 the nickel steel barrels (that say "NICKEL STEEL" in the exposed roll marking) usually have a steel/foundry identification stamp under the chamber. Early M54 proof steel barrels were also commonly stamped, but the practice was soon abandoned. 

So here are three '32 dated PROOF STEEL barrels in 250-3000 Savage.  These are all on M70s, which is not uncommon for 250 Savage.  Apparently they made a lot more 250 Savage barrels than they were able to sell on M54s and they can turn up on M70s as late as 1946 (fourteen years late!!!).

Two of these '32 date barrels are stamped "C.M.S.", which I believe Steve says stands for "Crucible Moly Steel" for the foundry and type of steel.  But what's going on with the first one that's stamped M.N.S. which would be "Midvale Nickel Steel"?  All three barrels are marked "PROOF STEEL" and have the correct integral forged front ramp.

I've never seen "M.N.S." on a M54/70 barrel.  Did they make any of the later M54/70 style barrel out of Nickel Steel, as the "M.N.S." would imply, and stamp them "PROOF STEEL"?  Is this an error in the under chamber stamp?  Or am I just confused (as usual)???

Best,

Lou

That is also great information.  Apparently, CMS (proof steel) was first used for the .22 rim fire barrels. 

For the Model 94, the transition from Nickel Steel to Proof Steel began in April of 1932.  Interestingly, the Model 55 (discontinued in early December 1932) used Nickel Steel barrels for it's entirety.  The Model 64 (the replacement for the Model 55) began production in November 1932 and it exclusively used Proof Steel barrels.

My Model 54 22 Hornet rifle was apparently manufactured in 1933 (33) date stamp on the barrel, and it has a Proof Steel barrel.  

Bert

This coincides with Steve's observations on the 52, which are always pretty accurate 😉

Best Regards,

seewin said

Bert H. said
Steve,
Additionally, the barrel on S/N 118 is marked "PROOF STEEL", indicating it is a post 1931 production piece, and approximately 12-years too late for the rifle in question.
Bert
  

Bert, the earliest Proof Steel barrels I have seen on 52's are dated "31" and in the 21xxx serial number range.
Steve
  

OK, that is good to know.  On the center fire rifles and shotguns, the Proof Steel barrels are all marked "32" or later.

That stated, Model 52 serial number 118 should not have a "PROOF STEEL" barrel on it (unless it was rebarreled at a later time).

Bert

Bert H. said
Steve,
Additionally, the barrel on S/N 118 is marked "PROOF STEEL", indicating it is a post 1931 production piece, and approximately 12-years too late for the rifle in question.
Bert
  

Bert, the earliest Proof Steel barrels I have seen on 52's are dated "31" and in the 21xxx serial number range.

Steve

btbell said
Twobit,
Not sure if you already have this in your database, but I participated in an auction in 2020 (won a beautiful 52B Sporter, lost on a deluxe boxed 75 Sporter - it's still painful!) where there were 5 boxed Win 61's, among others.
My guess, from the quality of the rest of the collection, is that all are genuine.
https://www.icollector.com/CHUCK-SCALLORN-ESTATE-AUCTION_a36597?p=1&ps=50&so=1&q=box
  

Thansk so much.  I will take a look and see if they have been captured previously.

Michael

TXGunNut said
I did spend 4-hours today at the shooting range.  I shot 100-rounds through that Model 61 you scammed me on.  The best I could get was a 1.5″ group @ 50-yards (using cheap Winchester bulk 22 Mag ammo).  I need to find a better brand of ammo and give it another try at the range. On a positive note, the Weaver K6 Steel tube scope looks good on it, and it dialed in quickly. -Bert
 
Bert-
As you probably know the 22WMR is probably more ammo-sensitive than the 22LR. Best I can tell every 22WMR I own has a different preference. I never shot my 61M so good luck! Glad you're getting some range time!
 
Mike
  

No, I was not aware that the 22 WMR is an ammo sensitive cartridge.  I do have some Federal and some CCI 22 Mag ammo that I can try. I do hope to find an ammo type that will shoot at least a .75" group @50-yds.

Bert

Additionally, the barrel on S/N 118 is marked "PROOF STEEL", indicating it is a post 1931 production piece, and approximately 12-years too late for the rifle in question.

Bert

Bert-

As you probably know the 22WMR is probably more ammo-sensitive than the 22LR. Best I can tell every 22WMR I own has a different preference. I never shot my 61M so good luck! Glad you're getting some range time!

Mike

Mike