Ray try the same load and adjust down in 1 tenth increments until your verticle displacement is at its very minimum only if it is required.
My rifle likes the same load for both those bullets mentioned.

JLouis

If it's a 32-40, you probably won't see much difference in POA/POI with that change of weight.  When I was shooting an original high wall, for instance, I used 13.6 grains of the late, lamented 4759 behind bullets from 165-200 grains weight with good results and very little change in impact at 100 yds.  I shot mostly Ram Bash with it like that.

Froggie

Range tested yesterday. The .322 based tapered bullet was tight to breech seat, when compared to my Mos with a .322 base. Tried charges from 12.5 - 12.9 in 0.10gr increments - none showed improvement over my Mos. Leading was severe. The 20;1 mix was identical to that with which I normally cast. Could the leading have been caused by the very tight bullet fit?I don't understand the leading, but feel I have a fine bullet from the Mos and will continue with that until I am inspired to try something new.

Ray where exactly is the lead build up taking place in the barrel? If its in the first third you could be shaving a little lead off the bullet. If it is more towards the muzzle it would typicaly be related to your lube.

JLouis

After knocking the seated bullet out of the bore - if there are land cuts to or past the bullet base ... shorten the seater plug so the land cuts stop about a 1/16th inch before the end of the base.  This will provide a perfect base on the bullet to preclude gas stripping in the grooves

John we quite typicaly seat the bullet until it engraves just beyond and all they way through the baseband to achieve the best in accurac. This is somewhat of the same approach as one does when loading through the muzzle where the bullet is also completly engraved. If one has a rifle that does not quite shoot I highly recommend one giving it a try and more times than not it will make a substantial improvement.
This could also be very helpful in eliminating Ray's issues as well as it also tends to help when one has leading issues if the bullet does indeed fit the rifle properly based on my personal experiences. Also if Ray does indeed try poping a primer and he does get gas leaking by it would also be a good time to try seating it per the above.

JLouis