Unless the gun is actually not performing the way you want it to, it's a waste of your time and effort and their time and effort and money.
Ok, forget all that and let's just assume that you feel like you need to pursue this based purely on measurements--without verifying that the gun actually shoots accurately or not.
1. You need to do the measurements properly. For accurate inside diameter measurements you need a pin gauge set. Get that (or find a gunsmith/machinist that has a set) and verify the throat measurements. It would not be smart (or ethical) to send the gun off for work based on measurements that may not be accurate.
2. You need to slug the bore. If the throat measurements are about the same size or a bit larger than the groove diameter then there's no reason to expect accuracy issues.
3. Keep in mind that since you have no data to verify that the throat issues (if they really exist) are actually causing accuracy problems with the ammo you are using, nor have you verified that there is not some other issue that could cause accuracy problems, you could get the gun back after the work (assuming Ruger agrees to do it) and find that it's not accurate.