Ross M1910 Pump Action conversion

[harry mac]

6.3x57 would be .257 Roberts. 6.3mm is the metric designation for .25". The Roberts utilises the 57mm Mauser case, so 6.3x57mm = .257 Roberts

[vykkagur]

6.3x57 would be .257 Roberts. 6.3mm is the metric designation for .25". The Roberts utilises the 57mm Mauser case, so 6.3x57mm = .257 Roberts

Well done, that man!

Why did none of us pick up on this sooner? I was so fixated on the metric designation, I never thought to look at American cartridges by another name. (The fact that I didn't know the .257 Roberts was based on the Mauser case is down to my ignorance.)

[Daan Kemp]

The 6.5x57 Mauser cartridge is almost identical to the .257 Roberts and predates it somewhat. 6.5x57 Mauser would be a logical cartridge for use in Finland.

[vykkagur]

The 6.5x57 Mauser cartridge is almost identical to the .257 Roberts and predates it somewhat. 6.5x57 Mauser would be a logical cartridge for use in Finland.

You're absolutely right, and we all went down the metric road too. But why, then, would the maker clearly stamp the barrel 6.3mm? The rest of the work (other than the nut and bolt trigger stop) does not suggest someone who makes such glaring mistakes. Short of being able to talk to the original builder (please chime in if anyone knows who that might be), the only way to settle the question is a chamber cast. If my geographic situation were different, I would love to get my hands on this rifle just to delve further into it's story!

[Eaglelord17]

People have used many different terms for different ammo in the past. 8mm Mauser is called many different things for example. 8mm, 8x57mm, 7.92mm, 7.9mm, etc.

7.5 Swiss or 7.5 French both use .308 (.762) bullets. 7.62 Russian uses .311 (7.7) bullets. Lots of different reasons for different namings based off what your measuring, how your measuring, etc.

[boltman]

Although this rifle looks odd and it looks like it would be awkward to shoulder, isn't it basically made in, "bullpup" style?

[NORTHOF60]

"Bullpup" configuration normally requires the trigger group to be in front of the magazine.

[vykkagur]

I think the flat and unfinished butt fits with the earlier suggestion that there is a thick and perhaps elaborate buttplate assembly missing.

[Promo]

The 6.5x57 Mauser cartridge is almost identical to the .257 Roberts and predates it somewhat. 6.5x57 Mauser would be a logical cartridge for use in Finland.

I agree with vykkagur, Sako is not the company who would by mistake put a wrong caliber designation on a barrel. Plus the mystery on the caliber was solved, it is .257 Roberts. Why should we now assume a company with such a tradition would make a typo or on purpose write the wrong dimensions on a barrel?

It is quite amazing that this conversion attracts so many people over the years and so many share their thoughts and input. Makes me happy I'm not the only crazy one who has such a passion for items this weird! And yes, I agree, the buttplate must had been an adjustable one. But based on the small size of the thumb and hand holes it might not had been a big one, since the person very obviously was rather small.

Edit: now imagine yourself out in the woods going hunting with this rifle in hands, atop a red dot sight

[vykkagur]

... based on the small size of the thumb and hand holes it might not had been a big one, since the person very obviously was rather small.

Perhaps it was just a guy with small hands. Not that that would be ME, of course. Just sayin;....