I plan on focusing on normal guns, sneak, lockpicking, science, repair, and medicine. I dropped my strength to 3 so I had more points for luck and agility. Now I am noticing that weapons have a strength value. If I am shooting a gun that says "STR 5" but mine is at 3, how much does it actually affect it?

On a side note, I just got this game today and I am in love. I don't know why I waited so long to play it.