I have a 1978 14" T/C .30-30 barrel that is a true 1/2 MOA barrel. No one would consider that inaccurate.
I've also had a 10".30-30 barrel, that was not nearly as accurate, but was satisfactory. Although I like that cartridge, it is just a bit overbore for a 10" barrel in my opinion, and either the .30 Herrett or .300 Whisper could be considered as good alternatives. Any of the 3 could be considered adequate for deer.
Personally, I wouldn't impose the arbitrary 10" limitation, and would go with a 14" in .30-30, .30-30 AI or .309 JDJ. All are excellent, and there is a noticeable step up in power to each.