What is a bigger bullet 45 caliber or 357?

The .45 caliber is bigger in diameter. If you mean weight. The .45 caliber is generally heavier. However there are some lightweight .45 caliber bullets that are lighter than .357 caliber bullets. Generally speaking .45 caliber bullets weigh between 180 - 230 grains. While .357 caliber bullets generally weigh between 158

• 180 grains.

If you are talking about diameter, the .357 caliber bullets are approximately 0.357 inches in diameter. The .45 caliber is approximately 0.450 inches in diameter. Again, using this measure, the .45 caliber is the larger bullet.