Is it me or are bolters the most confusing weopon around? they have massive bulky mags but only ever seem to have around 10 rounds in. Pics of marines firing seem to show them as semi auto or full auto surely the mag would would last for about what... a second?

I also realise that in firewarrior there are vid clips of marines firing that show bolters firing on single shot and they almost seem to be firing small rockets( which i accept is what the bolts are)

anyone else a little confused?