Sounds like you got to a good place!
For others who are still wanting to get a good feel for changes in barrel length, there are two things that can help. First, a tool that can give one a feel for how much muzzle velocity changes with barrel length for a given load. Here is one:
Velocity Estimator « Shooters Notes
Second, one needs to get a feel for what that change means in terms of bullet drop and drift. Remember, drop is a lot more consistent than drift, so look at the drift figures to see how much you will be affected by the unpredictable wind components in your calculations. (Most trajectory calculators use 10 mph crosswind component as the default. You may be good for a 2 mph uncertainty in steady wind and a little more for gusts. Either reset the 10 mph for your uncertainty value or use the 10 mph as your guideline.)
There are a lot of good trajectory calculators available, but my favorite is:
JBM - Calculations - Trajectory
You will be surprised at how little a 50 ft/sec difference changes things at typical .260 Remington velocities! It may still be important to you, so doing your own assessment is the way to go.