It's my understanding the 19 dash 4 is the last model that has the pinned barrel & recessed cylinder. It's also the 1st model of the famous 19 series K frames that had the strengthened top strap above the cylinder.

Previous 19's (no dash, 1, 2 & 3) were known to develop weakening at the front of that top strap if they were fed a steady diet of 357 magnum rounds.

The recommendation was to plink or practice with 38 special, and use the more powerful 357's for carry or self defense.

I never agreed with that because I've always felt you should practice with what you carry, especially in a self defense or every day carry situation.

So, my 19-3 is always at the ready with 38 sp ammo.