OK, great... let me break this down further, since you want to nitpick as well...
1) Have bomb parts (noun) -> creating illegal bomb (verb that doesn't effect anyone directly)
2) Have bomb parts (noun) -> using illegal bomb (verb that does effect someone directly)
3) Having gun parts (nount) -> creating illegal gun (verb that doesn't effect anyone directly)
4) Having gun parts (nount) -> using any gun illegally (verb that does effect someone directly)
Do you see how 1 & 3 are more closely related to each other than 1 & 3 are with 2 or 4 and vice versa?
Technically, 1 & 3 don't hurt anyone, whereas 2 & 4 clearly do.
Bad analogy.