I shoot BPCR silhouette,using rem.rolling block,1in16 ,30in badger barrel,chambered for 40-60 maynard. I am getting 2 in.groups at 100yd.with iron sights,and would like to tighten it up a little.Can anyone that shoots this cartridge give me any hints on accuracy loads. I am using goex fff,410gr.(20/1) out of saeco mold.

Sounds like you are on track already to me. When I have a rifle that will shoot bullets into the same hole at 100 yards, my groups are about 2" with open sights because my eye cannot tell the difference in sighting at that range.

However, I have heard that some guys take their volume measure, weigh the charge-then weigh the other charges to match the first one. Apparently they get a little more consistency this way and slightly tighter groups.

Are you using regular open sights? A rear peep and front globe always tighten things up. Perhaps you already have these on your rifle.

Haven't done a bunch of 40/60 shooting...but have a couple of questions. Nice round groups, or a bit more vertical or horizontal than round? Is that RB a converted Military (with a big crashing heavy hammer) or a more sporting version?

Like the old Rollers, but they can be "fussy" about little things that other rifles seem to just ignore. Know headspace with a rimmed round is supose to be simple....but one (an old 50-70) gave me fits. Think about the way the action works...as that hammer comes down, it does contact the breech (tightening it up just a bit). Now if the case is set just a tiny bit too far back, it will still shut...but as the hammer falls it runs into some drag as it forces the breech fully closed. That sometimes drag, sometimes no drag changes the force of the hammer blow.

Digging the grunge from the case rim recess each and every time I swabed the barrel cured that problem.

Big Country - Who did your barrel work? I have re-lined a Ballard barrel to .40 and have about decided to chamber it in 40/60 but cannot locate a chambering reamer.
My BPCR rifle is a Rem RB that I built on a #5 action, changed to pistol grip and converted to side lever (Like the Hepburn) I like the RB's, very simple and strong.

Big Countyr - you did not mention a wad.

Are you using any kind of wad?

Firstly, a 40-60 Maynard chambering reamer can be rented from Shawney for about $33. If you buy your brass ready formed from Dave gullo then get the headspace gauge supplied with the reamer or use the 30-40 Krag guage.
A 2 inch group at 100 yds is not a true measure of accuracy that can be achieved at 500 meters. Do your group shooting at 300 yds or meters. A load that gives consistant SD;s of 5 or less should provide verticle dispersions of not more than one minute of angle. Because of the wind sensitivity of BP cartridges in the 1100-1300 fps range I would not worry if the horizontals exceed a minute. While competeing in silhouette matches your spotters primary duty will be keeping track of the wind. If you do not have a person that shoots with you on a regular basis it becomes more difficult making wind allowances. Use 3F Swiss powder drop tubed to a height equal to where the base of the bullet will be when seated. Do this several times to ensure that you are arriving at the correct height, then weight the charge and record the number. Seat a .030 card wad lightly on top of the powder and seat the bullet to its proper depth. Use CCI or Win large pistol primers. DO NOT CRIMP THE BULLET. Give this a trial and see what you get. If the SD's are still more tham 5 try increasing your powder charge one grain at a time. Shoot a least ten shoot groups to get a good indication of what your load will do in a 10 shot stage with sighters. Foul your barrel before group shooting and blow tube properly.

Try 2fg ! JAGG