I would sure shoot it for groups before making any rash moves, but tight spots can mess up accuracy - or at least keep you from reaching full potential.
If you think about it, a tight spot anywhere in the bore will swage your bullet under size. Not to mention creating a nasty bit of fouling.
You might want to check out
www.beartoothbullets.com & do a search on fire lapping. Marshall Stanton, the proprietor over there has got it down to a science - & sells fire lapping kits that work. W/ regards to ballistic improvments, check out his articles in the archives on the .444 Marlin.
I shoot mostly hard cast w/ my revolvers, & am plagued w/ the characteristic tight spot that is created when the barrel is torqued into the frame. I typically lap 'em right out of the gate - to reduce leading & improve accuracy.
I also shoot a #1-S in 45-70. Accuracy w/ this rifle is outstanding w/ the right load. Although I have never noticed any tight spots (gonna have to go check now), I would not hesitate to fire lap it (as directed) w/ Marshall's product line.