All rifle casings in the game look the same, all pistol casings in the game look the same. Most people don't pay attention to the casings as they eject from the weapon, which is probably why they all look the same. The devs wouldn't waste hours of work to make sure each shell casing looks like it should when it is ejected, that is what I meant.
Actually, they did make more than one shell casing animation. As far as I can tell looking in the GECK, there is one shell casing animation that is used for all the auto pistols except the .22, and at least 3 casing animations for rifles: assaultrifle, 762 and 44. It is odd in that some are used where more appropriate ones are available, eg: while the Trail Carbine uses the 44 casing animation, the Cowboy Repeater uses the assaultrifle one. The .22 smg uses the assaultrifle one also. BTW, just in case anyone was interested, the .50cal AMR does use the 762 casing animation.
I stand by my earlier prediction that the K9xxx is at least .308 if not .50. Probably .50 since we already have an automatic .308 and Josh is probably sick of hearing us [censored] about not have a M2.
-Gunny out.