Don't know that it needs to be but I would . I shot them for a while in .50 and run them thru my Ideal #1 sizer . Did not change the size but it made sure they were perfectly round and lubed the grooves . Did the same with the .575's in my Zoli Zouave to straighten the skirts and squeeze a tad of the old black powder Lyman lube into the grooves to bolster the axle grease in the base .
Well, the same thing that say Eddie Southgate: calibrated and greased.
That may-be will not helps you but when I'm using that kind of bullets , Minié or compression bullets all them are calibrated and greased from the first groove to the last one. Only round bullets are fired out of the mold without grease but the patches are greased, so the bullets are always greased in a way or another...
Not an expert! I quoted T/C on another thread about bore size in .54. The top band is larger than the bottom and middle bands. I do no size them, but run them through the lube "tool" they use to sell. I do not believe this sized the bullet at all. When the bullet is in the right position ( a bit tricky!) a squeeze of the tube pushes grease (bore butter) into the 2 grooves at the same time.