Buffalo Bore makes very hot ammo and does not adhere to SAAMI pressure limits. They have a unique approach compared to industry standard companies. They put warnings on their ammo saying not to use it on certain guns. Just because they label that box of ammunition as 357 Magnum, doesn't mean you can shoot it in any 357 Magnum firearm. Buffalo Bore says to use it only in steel frame guns and warns against using this load in any lightweight alloy framed revolvers.
Interestingly the box end flap is labelled as "For use in all 357 Mag firearms in normal operating condition." Except it isn't according to their website!
Here is Buffalo Bore's warning on their website regarding your particular load.
BUFFALO-BARNES LEAD-FREE 357 Mag Low Flash-Short Barrel Field Proven pistol and handgun ammo. Maximum firepower bullets. Best ammunition for pistols and handguns for sale. Buffalo Bore. Strictly big bore. Strictly Business.
www.buffalobore.com
"Buffalo Bore type HEAVY 357 Mag. load and as such, should only be used in revolvers made of all steel. It should not be fired in a lightweight, alloy framed or cylindered revolver.
Feel free to use it in ANY/ALL 357 mag. chambered rifles and all steel revolvers/handguns."
Make sure you disclose what ammo you shot to S&W when you return the gun. S&W will probably blame the ammunition (rightly so) and Buffalo Bore will probably say you should have read their fine print.
When I'm not shooting my own reloads, I chose factory ammo from the well established companies that adhere to SAAMI. Buffalo Bore touts some impressive ballistics but it comes at the cost of higher than standard pressures and increased wear on your gun. Plus their small print says not to use it in certain guns. Bear that in mind when you buy ammo.