Best for what? 38 Wadcutter is a flat front bullet used in target competition, that is highly accurate, has low recoil, and clips a neat clean hole in a paper target. Heavier solid bullets are used for hunting, and fast light hollow point bullets are used for defense.
No
.357
It is marked on the barrel.
NEVER FIRE OR ATTEMPT TO FIRE AMMUNITION IN A WEAPON NOT DESIGNED FOR THAT AMMUNITION!!!!!!!!!!!!!!!!!!!!!!!!!!! Danger,danger, danger
No, unless it's a frame with barrels that can be changed to suit different caliber ammunition.
Most say 38 special on the barrel
NEVER FIRE AMMUNITION IN A WEAPON IT IS NOT CHAMBERED FOR!!!!!!!!!!!!!!!!! No, No, NO
If this is a .38 cal (check the markings on the frame and barrell) it is chambered for .38 caliber. If it is a Police Positive ammunition would be the .38 PP If it is a Police Positive Special you could use .38 PPS Check with any reputable gun shop/dealer or range and they'll give you the information you need.
38 special unless it's a 38 S&W, then 38 S&W cartridge. should say on barrel.
They measure the width of the gun barrel in fractions of an inch. A 38 caliber will be .38 of an inch. The bullet projectile itself is a little less wide.
NO.
Online; Gunbroker and Luckygunner may be able to direct you to a brick-and-mortar store near you.