Trying to work up a load for my 32-40. I am breech seating and I am getting a lot of leading near the breech. What might be the problem?

If the bullet properly fits the groove diameter, and the bore is in great shape, it shouldn't lead up. What is your bullet diameter vs. groove size?

Smokeless Powder, Fast Burning, Hard Alloy? If that's your Load you are probably not "Bumping Up" your Bullet, especially if it's not big enough to begin with. Are you buying your Bullets from commercial supplier? If so many of them use a hard Alloy and some kind of very hard Lubricant. If you are casting, go to a soft alloy and some reasonable Lubricant. 50%
Bee's Wax and some kind of Tallow or at least Crisco with Black Powder. If that relieves the Leading than you have an idea of the route you need to go in. Try Seating a bullet in the throat and then look thru the Bore from the Chamber end at a strong light source. If the bullet is slightly undersize you will be able to see light around the base of the bullet. Black powder loading can often fix this if the Alloy is soft enough. But in truth you should look for a better fit bullet. HTH Regards,
FITZ. OLD TUCK.

Thanks for all of the info. I am using DGL lube works well in my BPCR. The bull it base is .3215, grooves are 3.185. When breech seated the lands make the bullet nearly to the base of the bullet.
I will tr6 lubing before I start. When breech seated I see no light shinning through. I am using a 30-1 mix. Maybe I will give black a try. This is my first experiment with smokeless.

J Louis, it just so happens I have some and Iwill give it a try. Thanks, jim

Randy I think it is .030 from his comment! If so as Joe stated way to big. I would think he needs a .319 bullet. That said I would expect some pressure signs as well.

If it were to be actually .030 larger I would be quite surprised to see him even be able to breech seat it without it being a bit of a struggle. And if so while also seating it just short of engraving all the way through the base as noted it would also leave one hell of a fin hanging off the base of the bullet of which was not mentioned. If 2 to 3 thous. over groove I have found it to shoot allot better for me and have found 3 to 4 the better but only at the base. I think the reason why is it helps to promote a more consistent power burn and for it to also take place more consistently in the same area in the barrel based solely on my own long term personal experience. I was also one who openly stated that it should be groove, or a 1/2 to 1 thous. over before knowing better and then realizing what actually worked the best for my own personal results and the additional accuracy I then founding from it. 

JLouis

It all just boils down to what each individual or individual rifle likes the best and the later being the more important. What works best for one seldom works just as good for another. 

JLouis