Enforced idleness reaps dividends

[ukrifleman]

I have owned a circa 1942 Australian Lithgow No.1 Mk.111* for a number of years and it has always had a problem with a tight spot on the bolt when I extracted a case.

I lapped the bolt body and receiver with fine grade valve grinding paste to smooth out the action which improved things a bit but the problem remained.

I did this some years ago and the rifle spent most of its time as a safe queen, only coming out the mandatory 3 times a year.

With all this enforced idleness of late, I decided to revisit the problem and finally found the cause and the solution!

I noticed that cases were being marked on one side near the base as they were extracted and my first thought was a rough surface in the chamber, which proved not to be the case.

Running out of ideas, I removed the extractor (original OA marked Australian) and measured it against a spare Fazakerly extractor I keep as a spare and found it was 0.010 thinner under the claw than the Aussie one.

I fitted the Fazakerly extractor and Bingo! problem solved, no more binding of the bolt.

The action is now as slick as a SMLE should be, definitely a `mad minute` contender now!

I was surprised that such a small difference in dimensions, would have such a big impact on the pressure brought to bare on the bolt causing it to bind up.

I am relieved that in the end it was an easy fix and am looking forward to more range time with this old warhorse, now that is more user friendly.

ukrifleman

[snayperskaya]

A good result, it’s nice when things come together and don’t really cost anything

[ovenpaa]

A very good result and a nice looking rifle as well. I have a couple of .303 rifles to take out and shoot for the first time in the new year and sat down and made a reasonable amount of ammunition earlier this year, all labelled and fitted with O rings ready for the first firing of the brass. Roll on 2021.

[snayperskaya]

A very good result and a nice looking rifle as well. I have a couple of .303 rifles to take out and shoot for the first time in the new year and sat down and made a reasonable amount of ammunition earlier this year, all labelled and fitted with O rings ready for the first firing of the brass. Roll on 2021.

Might be a silly question but what are the O rings for?......

Edit......just read about it in the Shooting Shed Journal

[ovenpaa]

They make a huge difference to fit and longevity and the process can be applied to most bottle necked rimmed cartridge cases.

[snayperskaya]

They make a huge difference to fit and longevity and the process can be applied to most bottle necked rimmed cartridge cases.

Am I looking at it wrong or is this more of a headspace issue?, I’ve not seen this with any of my Mosin chambers.If I was to add an O ring to my cases I don’t think my bolts would close.

[ovenpaa]

Beware the the term 'Headspace' - this is for generous chambers. The O ring holds the case head tight to the bolt face and you can use O rings sizes to suit. I have seen case head separation on multiple cartridges including 7,62x54R and half of me is of the opinion I should bin my brass before it gets to that state, the other half questions why on earth anyone would shoot a case that is stretched just above the rim and this applies to many cartridges.

A customer rang me in the week and mentioned a case head separation on a .243

[snayperskaya]

Beware the the term 'Headspace' - this is for generous chambers. The O ring holds the case head tight to the bolt face and you can use O rings sizes to suit. I have seen case head separation on multiple cartridges including 7,62x54R and half of me is of the opinion I should bin my brass before it gets to that state, the other half questions why on earth anyone would shoot a case that is stretched just above the rim and this applies to many cartridges.

A customer rang me in the week and mentioned a case head separation on a .243

Ah, I see