Question about M27 and F mark

[kworm99]

Okay guys and gals, I'm having an issue with a Finn I just purchased. It's a 1930 m27 "F" stamp, no "D" stamp, could I assume that it's chambered in 53r? Any help is greatly appreciated.

[desdem12]

What is the problem you are having? The F is a throat relief designate. Not sure of the dimensions of the relief right off but it was a test for accuracy. The D is also a throat relief and was employed to use the larger d166 bullet. If you are having trouble chambering a round then I would suggest a switch to brass case ammo and see if that doesn't help out.

[Fishin Finn]

As I recall, the F stands for Fägernas, the type of steel used in the manufacture of the barrel. The M27 is said to have a .3095" groove diameter bore. I am not sure if I would assume that the chamber is for the 53R cartridge. Only the casting of the chamber and subsequent measurement would reveal the truth.

I believe the D mark was stamped on the barrels beginning October 1939, according to Doug Bowser a Finnish MN expert. Perhaps the rifle was diverted from the military before they were rechambered and the D marks were added, therefore the boxed SA stamp should be missing, as well, since the boxed SA stamp was used starting in 1942.

The D marking indicates a reaming of the chamber to lengthen the chamber, to avoid the seating of the bullet in the rifling while closing the bolt, when using heavier and therefore longer Russian bullets. To be on the safe side, I would not use milsurp ammo until it is checked out. The case may get pinched onto the bullet causing the chamber pressures to increase.

Not to get confused, on the Finnish Tikka M91's made in 1925 through 1927 had the markings A, B and C, depending on the groove diameters.

Also, B markings appeared on M39's and M91's of identifying barrels made of blanks of Belgian manufacture.

[Darryl]

From Vic Tomas at http://www.mosinnagant.net/

http://www.mosinnagant.net/finland/The-Finnish-M27.asp

"This "D" stamping denotes that the rifles chamber has been altered to accept the Finnish D-166 heavy ball bullet. This change was done to accommodate a chamber size that would be able to use all types of 7.62x54R ammunition. The Finnish forces had captured vast quantities of Russian ammunition and it often was not useable in the m/27 due to the Finnish rifles tighter chamber tolerances. This alteration solved that problem and enabled the use of all captured ammunition as well as the new D-166 ball ammo and MG cartridges of the Finnish weapons of the day. It is very uncommon to find a Finnish rifle of any kind that has not been marked with this "D" stamping to indicate this modification. One of the most puzzling markings commonly found on the m/27 is the capitol letter "F" found over the date of the rifle on the barrel shank. This letter was erroneously thought by others to be the designation of Swedish Fägestra steel used in the fabrication of the barrel production. This is not the correct meaning of the "F" marking. In actuality the "F" marking is one of three that were used. The trial rifles of the m/27 series were marked with an "A" to denote the shape and contuor of the neck area of the chamber. The Finnish army had been experimenting with different bullet loads and shell casing measurements to determine the optimum cartridge to achieve the greatest accuracy out of the m/27. The first shell designation with a modified casing measurements in the neck area-that was made with a much steeper shoulder than the normal Finnish 7.62x53R cartridge, was the "A" cartridge designation. This shell was not adopted for wide spread use and the marking was dropped. No known m/27 that I am aware of are found with this "A" chamber shape marking. (The author would be glad to offer a great trade should one pop up!)


The other marking that was used on the barrel was the capitol letter "F" which identified the chamber measurements of the "F" designated cartridge. This cartridge used a shallower neck incline as found on early Finnish 7.62x53R ammunition. The final marking of "D" is as outlined above. The final letter code of "D" indicated an alteration of the chamber diameter and shape to accept the Finnish D-166 cartridge that differed very slightly from the "F" chamber. So in review the barrel markings of "A", "F" and "D" were marked on the barrel of the m/27 just above the date and between the serial number to indicate the barrels chamber characteristic and what type of ammunition was capable of being fired through the weapon.
Vic Thomas"

[kworm99]

Yes I'm leaning toward chamber casting. Fishin Finn, the boxed SA is there. Dolk, so with the comment you posted, without having a chamber cast done I could assume there was no upgrade to this particular rifle?

[Darryl]

Yes I'm leaning toward chamber casting. Fishin Finn, the boxed SA is there. Dolk, so with the comment you posted, without having a chamber cast done I could assume there was no upgrade to this particular rifle?

That would be Vic Thomas' comments, but yes, I would agree with him (based on what you told us). Would rather see a photo of the barrel shank first though.

Dolk

[kworm99]

It's telling me that my photo is to big to upload.?

[desdem12]

You have to reduce the size for it to fit on here. I use paint.

[kworm99]

2013-11-27_16-41-08_219-1.jpg

[desdem12]

Don't be stingey. Pics of the stock and other features also. Not to mention if there are upgrades to it then there is a possibility that it may have other upgrades then just the stock.

[kworm99]

This is definitely my "new" favorite rifle!! There's also a very faint 1916 stamp on the stock behind the butt plate, but I couldn't get a clear picture of it.

[desdem12]

SKI TROOPER
Non upgraded front end and wing connectors on the bolt so I would say this is a straight up non refurbed hell of a beauty m27 ski trooper model, I love it.

[zeebill]

I have a winged bolt and unit disced M27 that is very finicky about what it closes on and excepts in the way of ammo. It will shoot well with certain vintage brass cased ammo and it is also F stamped. I assume it is an early rifle also. I shoot it but not much with brass cased surplus ammo. If it won't close easily on a shell it is not fired. I have checked the head space with different gauges and it is fine that way. Sounds like you may have a sister rifle huh? Bill

[kworm99]

Thanks desdem12. Sounds like it Bill, I've yet to fire mine though because I was trying to figure out the whole 53r or 54r dilemma.

[sgtheindl]

[Genetically Swiss]

Where can one find the exact dimensional criteria for the "F" chamber? And cartridge too for that matter? I have looked, so far, no luck.

GS

[desdem12]

http://en.wikipedia.org/wiki/7.62%C3%9753mmR Not sure if this is the F throat but is the cartridge that would have been used probly.

[desdem12]

Differences between 53-54r
* Round length: 77.00 mm (54R: 77.16)
* Case length: 53.50 mm (54R: 53.72)
* Rim diameter: 14.40 mm (54R: 14.48)
* Bullet diameter: 7.83 mm (54R: 7.92)
credit: surplusrifle forum and wiki

[desdem12]

From mosin.net
The other marking that was used on the barrel was the capitol letter "F" which identified the chamber measurements of the "F" designated cartridge. This cartridge used a shallower neck incline as found on early Finnish 7.62x53R ammunition. The final marking of "D" is as outlined above. The final letter code of "D" indicated an alteration of the chamber diameter and shape to accept the Finnish D-166 cartridge that differed very slightly from the "F" chamber. So in review the barrel markings of "A", "F" and "D" were marked on the barrel of the m/27 just above the date and between the serial number to indicate the barrels chamber characteristic and what type of ammunition was capable of being fired through the weapon.

[Joeinthehills]

My M27 popsicle 1931 Tikka is also "F", and no "D"; I know that the previous owner that shot it used 54r w/o any problems.

It also has the wings retained on the bolt so it never had that conversion.