The 30-30 AI is an awesome round for the Contenders and Encores, you will find it a pleasure to load and shoot.
That said, I have found that simply using factory rounds to fire form, will save you both time, and money in the long run and will generally shoot just as well as most handloads in formed cases do.
IF you insist in loading your own to FF, I have seen the .375 Winchester Brass recommended time and time again for being better than the standard 30-30 cases in strength and longer lasting. Myself, I have yet to wear out any of my standard cases. One thing they will allow you to do is set a false shoulder to get a tight fit on the case form the start. This can also be done with the standard cases by sizing them up to a .311 first then necking them down until you get a good tight close of the action.
I would however hesitate to recommend using the 125gr Ballistic Tips for hunting deer. I have found that with my CT and while using them in some reduced loads for my grandson through my .308 that they will not always give good penetration, and act more like a varmint bullet in most cases. The decisive turning point was a broadside shot on a coyote at 150 or so yards that did not pass through. When the taxidermist skinned him out he said the bullet was simply in tiny pieces, and didn't even reach the offside shoulder. Granted it dropped him, but not what I would want to use on a whitetail.
I have had great luck with the plain ol Rem 150gr CL's in both the spire point and the round nose made for the 30-30. They are also cheaper in bulk than most other brands. If I were going to recommend a BT it would have to be the 150gr ones simply due to a bit tougher jacket. Out to 200yds you should get great results form them. Another great bullet would be the Barnes TTSX in 130gr. You should be able to get it moving to about as fast as the 125gr loads and it will penetrate and expand properly at impact velocities down to around 1750fps. This was what we switched to for the grandson and we have taken quite a few hogs with them up to 200 or so pounds and out to around 200yds with no issues.
Good luck with your loads and your new barrel, I hope you enjoy it as much as I have mine.
