Hey fellas - I've had two handguns go back to S&W for re-barrel and have never been happier with the results. One was a M28 Highway Patrolman that cmae with a 6" bbl and the other was aM29-2 that came with the 6.5" bbl. I got tired of long barrels after 20 yrs of having them wear a hole in my hip every time I went afield with them. So, I sent'm back for re-barrel.
The M28 now wears a 3.5" M27 bbl and is blued to match. It is one beauteous chunka blue steel in my book, favors cast 200 gn semi-wadcutters and goes with me for 50-60 yd shots when I hunt whitetail.
The M29 now looks like a 4" Highway Patrolman. I wanted the narrow, tapered barrel of the M21 but S&W said that would illegally change the caliber designation and the only other barrel that was narrow and tapered was for the M29 Mountain Gun. They said they could install it, bead blast the whole revolver and blue it to match - it now wears a field perfect black matt finish (in my opinion). This one prefers cast 295-300 gn semi-wadcutters and is more accurate that I am.
I do not remember the cost but the service was well worth it. If S&W tells you you have a cracked forcing cone and need the barrel replaced I would believe them. If you think you can get a better job elsewhere for less but with the same quality workmanship and guarantees, go for it - but I really don't think you're gonna find it.
If your forcing cone is cracked and you don't want it to happen again, have it relieved to 11 degrees - that helps greatly reduce the initial shock of the slug entering the rifling and allows the bullet to introduce itself on a truer course down the barrel, giving better accuracy. HTH. Mikey.