Just trying to see if this is barrel wear or normal machining marks. It appears the lower half of the locking lug on my s&w 5944 is different than the top half. The gun locks up fine. Take a look and let me know if this is normal - bought the gun used and have run 700 rounds through it.
Here's a thread that discusses what we believe to be normal wear. Pic of my barrel in post #8 and Fastbolt weighs in in #9 w picture. Barrel wear ? (Solved)