the gun is new, so some issues are possible.
Generally speaking there are two reasons you get lead build up on the frame. The first is that your cylinder chamber mouths are not fully and correctly lined up with the barrel forcing cone. This results is shaving lead off the bullet (amount varies with degree of misalignment) and if bad enough results in "spitting" bits of lead out of the barrel/cylinder gap. A sharp edge in the right place left by machining and not properly polished out can do it, too.
This is a gun problem.
Another possibility is that your lead bullets are being very slightly melted during firing and a small amount of lead is being vaporized, and is condensing on the frame resulting in a lead "build up" there.
This is an ammo problem.
To check for spitting, put some white paper on both sides of the gun, far enough away so as not to be shredded from the gas from the cylinder gap alone (a few inches should do). Fire a round and check the paper. Torn by gas? ok, move them a back a little and try again. Look for holes and tears in the paper. Tiny little specks from burnt/unburnt powder is ok. Anything larger and perhaps jagged holes indicate larger things are hitting the paper, and that's from the bullet.
In extreme cases revolvers can be so out of time as to spit chunks large enough and hard enough to break skin.
If your new gun is spitting time to talk to the factory,
BUT before you do that shoot something ELSE in the gun to see if it spits with a different load, or not. IF its a gun problem it will be some level of problem with everything.
If the problem is the ammo, (and poor ammo can spit too) then other ammo should not show the same problem.
Clean the gun and run some tests, with different ammo, and your original ammo, cleaning inbetween. Nothing softer than steel (that isn't an abrasive) will harm the steel but it can "cloud" or dull a polished surface.
If you get lead build up with ammo A and not with anything else, the obvious answer is stop shooting ammo A, or put up with what it does and clean it regularly.
If you get build up with everything, then its time to talk to the factory and see about possibly repair.
SOME build up of carbon is normal. Nature of the beast.
I used to polish my black wingtips the first part of the weekend and spend the rest of it trying to get the polish off my hands. I did have occasion to get a couple of shoe shines at the airport when I traveled. Haven't seen a shoe shine station in a long time.
