I know the film industry likes to have 'bullet strikes' as highly visible, however most rounds fired into trees have no visible effect. This is especially true of the calibres you are suggesting. If you want to be realistic you do not need to show any explosion of material from the trees. As a matter of interest the same is true of strikes into most other material other than water, mud, sand and dust.
I agree with that , but you know many directors want to everithing "blow up" !!
Somebody can help me and say me what is the particularity of each series ?