DB... all the info above is correct. There are a number of known issues with Ruger wheelguns... mismatched cylinder throats is one, barrel restriction from overtorquing the barrel are the two biggest. I am dealing with both of those with my Flattop right now. I've had a good number of Rugers over the years... including a beautiful .41 Bisley stainless that was on my Bucket List... and none of them shot worth a poo, and I've sold all of them. Now that I know about the Ruger issues, and how to fix them, I kick myself in the rump for giving up... but I just didn't know.
The issue with the mismatched cylinder throats is one cylinder chamber may swage (or size) down a bullet more than a different cylinder chamber, and give you inaccuracy issues. The other facet is, on undersized cylinder throats, is the bullets are getting swaged down too small for proper fit in the barrel.
The barrel bulge issue... even with a perfectly sized cylinder, once the bullet pass into the barrel they are being swaged down by the restriction in the barrel caused by the overtorque of the barrel (just in front of the barrel forcing cone.) I don't know if this is a common issue with the REDhawk, but it is with the BLACKhawk.
Easy way to find if you are dealing with a barrel restriction or bulge is... get a very tight fitting jag and patch combo and run it down the barrel, if it hits a notable restriction... you have a bulge or restriction. There are different methods of dealing with it, depending on how carried away you want to get.
And the other poster is correct... you need to measure your cylinder throats with a pin gauge. If you send your cylinder off to get it reamed, it helps to know what your barrel bore size is so they can properly ream the cylinder throats for the proper sized bullet. In my case, my .44 throws all bullets high and left... way high and way left. I sent my cylinder off and got it reamed, but didn't know my bore diameter... so we guessed. It did help... sort of. My bullets still go high and left, but they group better. My next task will be to lap the barrel bulge down and see if I can get the barrel to throw the bullets more to POA.