I noticed that if the polymer m&p bodyguard 38 isn't indexed properly after the cylinder is closed, then there is a chance that the first trigger pull doesn't rotate the cylinder.

If you close the cylinder and don't align the chambers, then the chambers will align when you pull the trigger. This isn't the problem.

The problem specifically is that there are two clicks when indexing the cylinder. If you close the cylinder and rotate the chambers into a locked position, you will hear one click. If you pull the trigger at this point, the cylinder might not rotate. But there is an extra step that involves twisting the cylinder back and forth with some force until you hear a second click, at which point the cylinder is now locked and indexed. So now when you pull the trigger, the cylinder does rotate.

I looked in the manual and I don't see anywhere mentioned this extra step of wiggling the cylinder until you a hear a second click to index it. The manual just simply says, "close the cylinder until it locks" (my paraphrase).

Now I've heard that the polymer bodyguard uses a slightly different action than the old J-frames; it doesn't have an arm, but some kind of star that rotates the cylinder. So, it may be that this is a design feature for the cylinder to not have to rotate on the first pull, as long as the chambers are aligned.

Anyway, I emailed S&W asking if this is a feature or defect.