Go here http://ut3.gamersmafia.com/descargas/show/5402 and cut and paste the code provided into your utgame weapon .ini like it says. I like a dot and and used that one - bUseCustomCoordinates=TRUE
CustomCrosshairCoordinates=(U=476,V=29,UL=5,VL=5) and also changed the color to this as well- CrosshairColor=(B=255,G=255,R=0,A=255) this will make a teal green dot which is easier for my old eyes to pick up even over red or pink or gold ! you cna change the size of whatever crosshair in game under the weapon tab to scale it up or down. This was one thing that was driving me crazy about ut3 ,was the stock crosshairs are too hard to see.
Give it a try !