Odd sized action screws *FOUND*

yorgi

yorgi

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Planning on de-sporterizing a M1903 Greek Mannlicher Schoenauer soon, so I'm gathering all the needed tools.

Action screws are apparently threaded in an odd and hard to find pattern, namely 1/4"-27. Would like to find
a die of that size to make a couple of action inletting screws for the project but they're impossible to locate.
Apparently, the 1/4"-28 dies are easy to find but there's a risk of damamging the action threads.

Some people say that the metric 7mm-1 size is close enough -and easy to find- does anyone know this to be true?
Again, it's only for test fitting the action to the stock, won't reside on it permanently but I'd like to have
a reasonably good grip between action screws and action while I'm working on the stock. Thanks.
 
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If that 1/4-27 thing is right then metric screws won't fit either. A 1mm pitch is going to result in 25.4 TPI. And that's a worse fit than a 1/4-28. Also 6mm is only 0.23" so you'd only be touching the tips of the threads with the wrong pitch.

Do you have the screws? Never mind what folks say. What do YOU measure the screws as being? And if you don't have a thread gauge then now is the time to buy one.

If the screw measures very close to .25 I'm thinking that the thread size might be a 1/4-26 BSF. It just depends on what threading system Greece used back in the day that this rifle was made. After all, it wasn't until WW1 that the Unified Thread Standard gave us the UNC, UNF and UNEF thread sizes.

But either way measure what you have and figure out what it is before you leap to a fit which will ruin the threaded parts you have.
 
BCRider said:
If that 1/4-27 thing is right then metric screws won't fit either. A 1mm pitch is going to result in 25.4 TPI. And that's a worse fit than a 1/4-28. Also 6mm is only 0.23" so you'd only be touching the tips of the threads with the wrong pitch.

Do you have the screws? Never mind what folks say. What do YOU measure the screws as being? And if you don't have a thread gauge then now is the time to buy one.

If the screw measures very close to .25 I'm thinking that the thread size might be a 1/4-26 BSF. It just depends on what threading system Greece used back in the day that this rifle was made. After all, it wasn't until WW1 that the Unified Thread Standard gave us the UNC, UNF and UNEF thread sizes.

But either way measure what you have and figure out what it is before you leap to a fit which will ruin the threaded parts you have.
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Just going by what I gleaned from Google, sorry. Your knowledge on the subject is obviously leaps and bounds above mine but from what
they said the pattern in question is a 1/4-27 Whitworth, identical to the Steyr M95 action screw threads.
Forgot to mention that the rifle was produced by Steyr and they kept the thread sizes the same until the end of WWII. Thanks for the response.
 
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Unified Thread Standard is American. That'd be the 1/4-28. Your 1/4-27 screams European and not metric. Rumoured to be British Standard Whitworth. Not a Greek thing, Steyr-Mannlicher. However, like BCRider says, if you don't have a thread gauge, go buy one.
 
sunray said:
Unified Thread Standard is American. That'd be the 1/4-28. Your 1/4-27 screams European and not metric. Rumoured to be British Standard Whitworth. Not a Greek thing, Steyr-Mannlicher. However, like BCRider says, if you don't have a thread gauge, go buy one.
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Thanks, I will.
 
Princess Auto in Scarborough. 1455 McCowan Rd. Leave your credit cards at home and give yourself lots of time. Princess Auto is a guy's store.
 
Sometime it is cheaper to pay for it, rather than buy tools and to attempt it.
Find a local machine shop with a lathe that can do this.
threads-0.jpg
 
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Or you could pillar-bed the action. Make the pillar, screw the action, bed the whole thing (putting devcon to glue up the pillar in the stock) and when all is dry unscrew the action, pop out from the stock and be happy.
 
Doggone it! The fine pitch put me off and I completely forgot about Whitworth. But hey, if I helped point you in the right direction it's still a win, right? :D

I've worked with and talked with a bunch of folks over the years that grew up over in "Jolly Ol' England" and worked with the mish mash of threading standards. Not only did Britain have three unique systems of their own but then the rest of the world tossed in UTS and metric on top of it all.

Then again even metric isn't one solid system. The Asian metric system tosses in oddball pitches that are not used in Europe.
 
Found a source for a couple of spare action screws at $6 a pop. I could take the easy way out and cut the threaded
portions from the screws and have a friend weld them on to 1/4 rod.
 
Watch it and read up on the thread form. It's a fair bit different from the angles and flat top you're used to on the UTS and metric system threads.

Also cutting thread pitches that fine on a lathe is a real bugger. I've done it but such a small amount of movement makes such a big difference to the fit.

If all you're after is to make up something temporary to hold the action for some work to be done what I'd suggest is simply thread in some short lengths of 1/4OD nylon tubing as used for water feeds to fridges and the like and then screw a 10-32 into the inner hole of the nylon tube bushing. This should lock things well enough to get by for the work you're doing.
 
BCRider said:
Watch it and read up on the thread form. It's a fair bit different from the angles and flat top you're used to on the UTS and metric system threads.

Also cutting thread pitches that fine on a lathe is a real bugger. I've done it but such a small amount of movement makes such a big difference to the fit.

If all you're after is to make up something temporary to hold the action for some work to be done what I'd suggest is simply thread in some short lengths of 1/4OD nylon tubing as used for water feeds to fridges and the like and then screw a 10-32 into the inner hole of the nylon tube bushing. This should lock things well enough to get by for the work you're doing.
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What a neat trick! Thanks for advice BCrider. A CGNer with an appropriately sized die is going to make a couple of screws for me.
Man I love this site! Thanks for everyone's help.
 
There is also a company in New York that carries Whiworth and BSF screws. I'm not at home at the moment so don't have the details here but I'll find it in the next couple of days and post it here for reference. I got a couple of screws from them for my P-H .22 Hornet Martini earlier this year.

Happy New Year, everyone.

:) Stuart
 
josquin said:
There is also a company in New York that carries Whiworth and BSF screws. I'm not at home at the moment so don't have the details here but I'll find it in the next couple of days and post it here for reference. I got a couple of screws from them for my P-H .22 Hornet Martini earlier this year.

Happy New Year, everyone.

:) Stuart
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Found it: http://www.britishfasteners.com/ :)
 
Received the package from a fellow CGNer (remp49) and couldn't be happier with his work. Two action studs as well as two T-handle screws properly threaded for a MS, tried them out and they work just fine.

 
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