Had an interesting failure with the 642 with the 32 barrel and 32H&R cylinder reamed to 327 Federal. The small group I shoot with every Tuesday evening had a silhouette set up at 40 yards to simulate the recent situation in the Texas mall. We took turns firing 10 rounds trying to stay under 14 second. I had never fired the 642 since putting it together, and my first turn using 32 longs I only got 4 rounds all right at the bottom of the target. My next turn I used a neck hold and got 7 of 10. I am not unhappy with that using a light 2" gun. I did a cylinder at 10 yards and got cluster just a bit bigger than a golf ball. I am happy with the gun firing 32 longs. I had no H&R rounds, but had some Federal 100gr jacked soft point. So I try a cylinder full on the 15 yard steel plates. It was going fine, then gun locked up after round 5. The problem was a small piece of copper stuck above the barrel extension rubbing on the cylinder face. I popped it out with the tip of my knife and gun runs fine. I don't get it. After I set the B/C gap I recut the forcing cone, the carry up is a tiny bit early if anything, going from a 5 shot cylinder to a 6 and I can feel just the tiniest bit of extra pressure right after the stop locks it up as hand squeezes by each tooth. Actually kind of stages the trigger. The cylinder is positively locked up when the hammer falls. The jackets taper so that only about .22 of lead on tip is exposed. The bullets do have a pretty deep knurled crimp groove and I am wondering if a piece of the jacket behind one tore leaving the crimp and ended up stuck between frame and barrel. As you can imagine, the recoil is pretty sharp and I also wonder if that caused the bullet in round 5 to have torn at the crimp a bit before being fired, then pealed off when fired. The cylinder is long enough the bullet could jump forward almost 1/4" before it would stick out of cylinder face.
I just find it hard to believe it was shaved of on top with the forcing cone I gave it and its alignment. If you shine light though the B/C cap and look down the barrel, the alignment on all chambers seams to be dead on. Plus, the crane on the 642 is stainless instead of alloy like on the 431pd which I first used the cylinder firing 327 rounds on with no trouble.
