How old is your daughter and how tolerable of recoil? I loaded 120 b-tips for my daughters 7-08 at a reduced velocity around 2400 fps with very little recoil and worked very well for her first buck in 2013. The recoil factor is very important with the younger shooters, if it kicks too much...
I have shot them out of a couple of in-lines and they have shot well out of both. They can be a real pain to get started in some barrels, not fun in the Remington I had but they start pretty easy in my CVA Accura V-2. I have never shot any animals with them but recovered bullets look good and...
I also have the 700 Tactical and the Hogue stock had to go. I put mine in an HS Precision and it made a huge improvement. This gun is a shooter, especially with 53 grain V-Max and 69 Sierras. Just added a EGW tactical bolt knob to it just to give it a more tactical look and it turned out great.
I would definately try the Rackmasters especially with your smoothbore and for around 7-8 bucks a box not too crazy expensive. Who knows they just might be almost as good as the Buckhammers. The Hammerheads from slugsrus do say they are for rifled barrels but I would think they might be ok too.
Scotty there is a slug called a Hammerhead that is similar to a buckhammer and sold from slugsrus.com as a reloading component. Might be another option for you to consider.
It is a shame Remington dropped the buckhammers, they were by far the most accurate slug out of my Hastings slug barrel and they are absolutely lethal on deer, proof is in your blood trail.
Have you tried the accu-tips, hear a lot of good with them. Used them in 12 gauge and shot really well and seem to open good on deer. They are supposed to be a good combo with the savage 220.