Just a thought but if you use take aim each shot is worth 4 rep so if you use your lowest damage ammo and use take aim just long enough for the scale to come up you will do the lowest damage to get the 4 points making it possible to shoot each baddie 25 times for 100 rep then switch wep as this is the max allowed per wep. You may not be able to shoot everything 25 times but you will get max rep with your gun for each enemy this way. I know somebody made a leveling guide back in the day I will try to find it and give a link.
K found page talks about rep for all weps hope this helps
http://www.piratesonlineforums.com/f...ead.php?t=6155