Vintage SF 9P question

[donn_]

Here are 2 vintage round-body Surefire 9Ps with different turboheads.

My question has to do with the knurling patterns on the bodies. As you can see, one has a single long section of knurling, while the other has 2 separate and shorter sections.

Can anyone tell me which came first?

 

[Sgt. LED]

I guess the one on the left was first.

 

[Size15's]

I agree - the one on the left is older.
SureFire haven't always 'defined' the edge of the knurling with the 'channel'.

 

[LumenMan]

One of the first 9P's that I ever owned had a body like the one on the left. I brought it used from one of the retired L.E.O.'s in my department.