[Jim243]

I am trying to remember your questions while typing this. (LOL)

Your seating die will do a proper roll crimp on the case, so no you do not need a separate crimp die.

The second grove on the bullet is for "lube" and should be red, blue or white grease. If blank then it means that the lead bullet has not been lubed and sized. (separate press needed)

As to OAL, your bullet cannellure should be at the correct OAL for you to do a roll crimp on it. Your load data maybe using a different bullet for it's load data.

That present two distinct problems, One is what is the correct load for the bullet you are using? And Two how do you correct for it?

The shape and size (weight) of a similar may work out, then again it might not. Measure the length of the bullet you have and see if you can find a similar bullet and load data in your manual. A copy of the LYMAN 49th EDITION would be a wise purchase because they are less MFG specific as to bullets and cover a wide range of lead loads.

If all else fails then find the load data for a close match and start you loads at Min charge weight, crimp to the cannellure and go up 0.2 grains at a time till you find the perfect match of bullet and powder without going over pressure.

Good luck and stay safe.
Jim