If the rifle sounded normal when you shot, it could have been shot placement. If you hit high in the chest, many times they do not start bleeding until the actual chest cavity fills with blood. Especially if you hit no bone going in, which does not allow the bullet to start to mushroom. You very well might have mortally wounded a number of deer. Since you discovered the rifle is dead on.

Bullets react different due to powder, but mostly shot placement. When the bullets are high shoulder shots, they hit, and expand, causing a massive wound and usually dead where they stand or they bleed soon. I suspect the deer you shot at and then report no blood or sign of hit, might have been hit in areas where bleeding takes time.

You can change bullets. But shot placement with any bullet is important. I really don't know what to tell you.