12 gauge 2 3/4 shells, is #4 shot the same for all loads (buck, field etc)?

[waloidian]

After shooting some #4 pheasant loads, the pellets appeared much smaller than what I rememeberd #4 buck being...maybe Im having bad memory and there is no difference in size?

edit, read online that buck and field are definetly different ratings. so the numbers are not comparable.

 

[Don]

#4 buck is LARGE, #4 shot is like BB's from a airgun.