Thankyou for your reply,
I have considered the M4, and may purchase one at some point.
The M3 has always interested me in its dual capability and also the possibility of using a longer vented barrel if I desired.
So far from what I read the M4 has no barrel options. I understand that for the purpose it was designed it seems to have no rivals, but at this time I am looking for a little versitility as oppose to a straight combat weapon.
Thanks, Don