Also check each chamber throat to make sure that they are not smaller than your barrel measurement. I have several model 29's and I have never seen one where the throat was smaller than the barrel but there is always a first time, they usually measure .430-.431
Ruger on the other hand is more prone to a miss match and there are lots of articles out there on how to fix it.
Easiest way to check is once you have slugged the barrel, drop the slug in to each chamber and the slug should either come out the other end with mild resistance or fall right out. If the bullet stops in there and needs to be pushed back with force with a pencil or something then we have a problem. The chamber is smaller than the bore and leading and inaccuracy are it's lot in life if there is a big difference, until the chambers are opened up by a gunsmith.
Measure the slug with calipers/micrometer and usually 1 thou over is good.
As far as molds go I will echo Ben's remarks and go for a good quality mold design and bullet design.
The lee 2 cavity molds are crap, after about 100 pours the mold hinge bolt starts to loosen and it gets hard to align the crappy alignment ridges together. You find yourself forever cleaning out the lead residue from the ridges and you physically have to put the two halves back together with your gloved hand to align them for the next pour.
The Lee 6 cavities are totally different and will last a long time and are good quality.
Lots of mold makers out there with different designs and quality of molds, jump over to
http://castboolits.gunloads.com/ and there are lots of specialty group buys going on and lots of info to correctly choose a design and mold maker.
I have over 30 different molds for the .44 Mag and basically I have narrowed the ones I use to 3 different ones with the Lyman 429421 that I had specially made to .432 diameter in a brass 6 cavity mold as my favorite and most accurate in all my .44's.