Really depends what you are wanting to use it for. If looking for a pistol, then get the tac 8. Are you going to carry it in a holster like a backup? They also make a good day of paintball when using only a pistol. If you are wanting to make a rifle or long marker with all the add ons, then go with the Tac 9.

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"A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort." - Herm Albright