I know this thread is quite dated, but I found it helpful as I knew the diameter, but not length anywhere.

While searching my collection of Metal scraps I couldn’t find the correct size. I didn’t want to sacrifice one of my good letter drill bits. I finally found the EXACT diameter, a TIG rod, .059. Hope this helps others.

Mines for a retired 65-3 I’m restoring to use as a shooter for training youngsters. I’ve restored 2 model 10’s and model 64. For some reason the younger crowd are drawn to the revolvers as I think they’ve never seen them.