G-Gunter:
Unless you were using the Winchester "Power-Plus", I doubt very seriously you were getting 2,390fps from your .30-30.
All the factory ammo I've chrono'd through the years have run around 2,250-2,275fps from 20"bbls. Around 2,325-2,350fps from 24" bbls.
My personal .30/30 load is 34.0 to 35.0gr of RL-15 under a 150gr bullet. It gets 2,390-2,450fps from a 20"bbl and is notably "stouter" than any of the factory loads. 33.0gr and a 170gr gets 2,220fps from a 20"bbl.
Only real difference though, is that the faster they go, the less they penetrate at a given range.
As you noted though, there is nothing wrong with a .30/30 at 175yds to 225yds with a well placed shot. Only it starts getting a bit harder past 200yds to precisely place the shots due to misjudged ranges. Actually, for most hunters, especially those with computers and .30/30's with scopes; the best investment would be in an inexpensive laser range finder. If you have time to "lase" the range, you can look at your stock where you have (should have) taped a piece of paper listing rise and drop with various ranges to 300yds.
I suggest using one of the available "on-line" ballistic computers, such as Norma's or the JBL sites. Use a b.c. of 0.200 for 150gr Rn/HP's with factory ammo, and a m.v. of 2,275fps. Use 0.220 for 170gr with m.v. of 2,150fps for the 170grs. Any errors will be insignificant due to radius of error (accuracy) of average rifles. 2" at 200yds is insignificant due to ~3-5" accuracy, and ability of most of us to hold a rifle still enough to shoot that well from a field position.
But as you noted, the "Proof" is in the venison stew you've enjoyed!