Short answer: I don't believe just polishing the chamber will improve your accuracy.

I had a similar issue, also with a 7-08, and replied to another post about a month ago, repeated here: I bought a new 110 Storm in 7-08 this past February. After trying dozens of different combinations of bullets, powders, charges, seating depths, and scopes, I could not get groups smaller than 2.5-3" I checked the bore with the help of a local gunsmith and found some strange rifling images. I sent it back to Savage. They sent it back to me with a note saying they "polished the chamber" and the rifle is shooting 3/4" groups. Going back out to the range, I could tell no difference, so I asked Savage what they used to test the rifle. Their answer was Winchester 140 gr Ballistic Silvertips. I bought a box (rather pricey) and they shot a little under an inch. I loaded some Nosler BT's (same bullet, except for the black coating) and they shoot 0.8 to 1.0" I have since tried other bullets and factory loads; the only bullets that shoot well are Nosler BT's in 120 or 140 gr, neither of which would be my first choice for a bullet. I will try some Accubonds as soon as I can find some on sale.

As to the time issue, total time to get it back into my hands was right at one month. I called a couple of times to check, because I needed it back for an upcoming trip. As it got finished up and I was approaching my departure date, a very nice young lady went out of her way to ship it back to me via UPS.