The Long Barrell all black model from Chicago Pneumatic. might be a CP 715 part numberNot to be confused with that crappy Central Pneumatic brand ************* Harbor Freight sells.
I would also recommend Astro Pneumatic's big nasty as seen on You Tube's South Main Auto Repair Channel.
If you have money to burn, the Snap on PH4650 (i think) is a stout air hammer too.
+2. I love my Snap On PH3050. I normally am a big fan of IR air tools, and not so much SO, but this air hammer is one place that I think SO is money well spent.We have the Snap On 3050 at work and it really gets the job done like no other. A tad on the pricey side, but buy it once and know that you are prepared for whatever is thrown your way.