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Hi all, my first 1919 build. After machining the bolt to spec as near as I could, and assembling/testing the gun, I realized that, with the sear spring in place, the surface of the sear sits maybe 2-3 thousandths above the bolt surface (just to be clear - I'm not questioning KMP's plans - any variation from plans is purely my doing). If I push in the sear, it goes about 4 thousandths below the surface of the bolt - just estimating, I didn't mic it.

I now notice there is a wear mark on the rear of the bolt, where it hits the buffer for the springs in the handle. I'm wondering if there's a potential issue with that buffer hitting the bolt face/sear, with the sear sitting slightly above the surface. Issues like cracking the sear over time? I don't know if I messed up the machining, or if that's pretty normal for the KMP sear, and with the clearance below the bolt surface the sear having enough room to avoid stress or impact cracking. Does anyone have any input or experience with this? Should my machining have left the sear slightly below the surface, under spring tension, or is this within acceptable tolerances?

The gun operates normally, meaning it feeds, loads, fires and extracts fine, firing rounds.

I can't really do anything about it now, but I'm interested in hearing whether this is an issue, in the experience of the forum members.

Thanks,
2KYards
 

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Mine has a shadow on the sear in the same place. It rides a bit higher than flush, but fully clears and then some when pushed forward into the bolt. I think they may all be like that by design. My friend's was also that way.

Don't just take my word for it though. I've been wrong many times before.:tongue:
 

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The sear should not stick out of the rear of the bolt. Ideally it should be recessed in about 0.005" and you shouldn't have a lot of slop. Sounds like the slot was cut too shallow when it was opened up for the semi sear. If you look at a fa bolt and sear you will see the sear never contacts the buffer.

You could grind down the back of the sear so it's recessed where the buffer would impact.
 
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