Ross M10 MkIII striker issue

[Gingercat]

Hi,

I took my new to me Ross to the range for the first time last week, but after firing the first 3 rounds fine it then failed to strike the primer. I had a couple more attempts but then gave up.

The cocking piece was moving forward ok, but the firing pin was not contacting the cartridge primer at all...

I disassembled the bolt when I got home, but found it relatively clean inside and no obvious damage to the mainspring or firing pin.

Any ideas? I was using factory ammo and had no difficulty in closing or opening the bolt.

If the spring is weak and needs replacement, do you know any sources for a mainspring?

Thanks for reading 😊

Information

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[steveu]

Was the bolt fully forward and locked into battery?

[Gingercat]

Was the bolt fully forward and locked into battery?

Hi, I thought so, but perhaps I just didn’t push the bolt firmly enough home. I will try with some different ammo to see if that makes any difference, as I’ve asked the question elsewhere and most responses are saying it’s a bolt closure issue rather than a weak spring.

[AGB-1]

https://www.gunsprings.com/RIFLES%20&%20SHOTGUNS/cID2
They do not list one for the Ross, but they might be able to make one with the measurements from yours.

[Surpmil]

When dry-fired how does the speed of the firing-pin's travel and force of impact appear to you, compared to other surplus arms such a Lee Enfield? Quite a few MkIII Rosses seem to have quite weak springs.

I'm guessing they were sourced in wartime from factories that didn't know or didn't care, or cared more for the Central Powers!

[Warren]

Drop me a PM...
I still have a pile of parts.

[Gingercat]

When dry-fired how does the speed of the firing-pin's travel and force of impact appear to you, compared to other surplus arms such a Lee Enfield? Quite a few MkIII Rosses seem to have quite weak springs.

I'm guessing they were sourced in wartime from factories that didn't know or didn't care, or cared more for the Central Powers!

Many thanks for your reply. The primer impacts on the 3 cartridges fired did vary, with one much deeper impact than the other two. The speed of travel dry firing seems good and the spring itself felt pretty strong when I was working against it to disassemble the bolt. So I’m not sure whether it was a bolt closure issue. I’ve thoroughly cleaned the area of the screw threads in the receiver with Hoppes and a tooth brush, so will see if it has made a difference.

Kind regards

Mike

[Surpmil]

Many thanks for your reply. The primer impacts on the 3 cartridges fired did vary, with one much deeper impact than the other two. The speed of travel dry firing seems good and the spring itself felt pretty strong when I was working against it to disassemble the bolt. So I’m not sure whether it was a bolt closure issue. I’ve thoroughly cleaned the area of the screw threads in the receiver with Hoppes and a tooth brush, so will see if it has made a difference.

Kind regards

Mike

I would bet your deduction is correct that if the bolt was not fully forward, the spring expended most of it's energy in first closing the bolt, then striking the primer.

I happened to see an advert recently for a Ross Mk.III in decent shape over there for whopping £2100. Yikes!

[Gingercat]

I happened to see an advert recently for a Ross Mk.III in decent shape over there for whopping £2100. Yikes!

Not surprised on the price. They are a very scarce rifle here and I’ve only seen a handful advertised for sale in the last few years.