Bending the hammer may not be the right fix. Have you tried checking the position of the lock plate in the stock? You may have over tightened the lock screw, causing the lock to sit at a slight angle in the mortise. Try loosening the lock screw, positioning the hammer in the correct position over the nipple, and while holding it in that position, gently tightening the lock screw. It doesn't need to be real tight.
Another fix is to shim the lock plate to change the angle of the hammer to the nipple. The shim should be about an inch long and 1/8" wide, and about the thickness of paper cut from a business card or plastic cut from a Coke bottle. If the hammer is off to the right of the nipple, put the shim between the lock plate and the mortise at the bottom of the lock plate. If it's off to the left, put the shim at the top of the lock plate, between the lock plate and the mortise.
Another fix is to gently scrape wood in the mortise to change the angle of the lock.