Surprise short pinion/ 6-40/ "round" lock bar rear sight.

Recovering from surgery & bored, so I got out my DCM (Jan 86) M1 Rifle. After some disassembly, started to research some of the parts. It's a SA s/n 1.63 mil, so the lock bar rear sight isn't so unusual, but when checking it I found that it's the short pinion/ 6-40 thread with a "round" bar.

I can see why they didn't last very long. There's no way to secure the bar and if it's loosened more than about 5 clicks, it falls off...and in my warm, well lit shop it was a pain to replace. In a freezing foxhole in Bastogne that would be an issue.

Aren't these worth some $$$ ?

Aren’t lockbar sights worth some cash? Hell yeah they are. $100 or $150ish on eBay.

Short opinions and type 1 lockbars are worth a lot more than type 2 or 3 long pinions & lockbars

My friend in NJ paid $600 to Debbie M for a Type 1 lock complete rear sight assembly and my friend in Calif said they were as high as $900 for a complete assembly.

When I was an armorer I found some Type 1 lock bars which I took with me as everything used the type 2 & 3 lock bar except the sniper rifles which were all H&R M1D

I even found a Type 1 lock bar that some GI forced on a type 2 long pinion and crossed threaded the lock bar !

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Originally Posted by RCS

I even found a Type 1 lock bar that some GI forced on a type 2 long pinion and crossed threaded the lock bar

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WOW! That was one determined GI...to thread a 6-40 lock bar on to an 8-36 pinion.

On the Type 1 that I have, the "Battle Range" triangle lines up with the 300 yd. mark on the elevation knob. Is this correct?? So far I have been unable to loosen the screw that holds the 2 parts together. Is this screw a normal RH thread?

This image from a website.

Quote:

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Originally Posted by Boonie Stomper

On the Type 1 that I have, the "Battle Range" triangle lines up with the 300 yd. mark on the elevation knob. Is this correct?? So far I have been unable to loosen the screw that holds the 2 parts together. Is this screw a normal RH thread?

This image from a website.

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Yes, it is a RH thread.

Yes, it is a RH thread.

Thank you. After a couple days of heating with electric heat gun & penetrating oil...and some judicious application of force, I was able to get it apart & no damage. :p I don't think it had been dis-assembled since WW2.

I found a photo of my SA rifle s/n 613217 with SA -6-42 dated barrel. Stock is short channel GHS (faint cartouche)Attachment 88423