The most common bullet grain weights vary depending on the caliber and intended use. Here are some examples of commonly available bullet grain weights for popular calibers:

1. 9mm Parabellum (9mm Luger): Bullet weights commonly range from 115 grains to 147 grains. 115 grains and 124 grains are particularly common for 9mm.

2. .40 S&W: Bullet weights usually range from 155 grains to 180 grains, with 165 grains and 180 grains being popular options.

3. .45 ACP: Bullet weights typically range from 185 grains to 230 grains, with 230 grains being the most common.

4. .223 Remington/5.56x45mm NATO: Bullet weights commonly range from 55 grains to 77 grains. 55 grains and 62 grains are the most widely available.

5. .308 Winchester/7.62x51mm NATO: Bullet weights often range from 150 grains to 180 grains, with 168 grains and 175 grains being popular choices.

6. .30-06 Springfield: Bullet weights typically range from 150 grains to 180 grains, with 165 grains and 180 grains being common.

These are just a few examples, and there are numerous other calibers and bullet weights available on the market. Bullet grain weights can vary significantly within each caliber, and different bullet weights may be preferred for different applications, such as target shooting, self-defense, or hunting. It's important to consider factors such as barrel twist rate, intended use, and manufacturer recommendations when selecting the appropriate bullet grain weight for your specific needs.