Lots of factory ammo is made on the lower end of the spec so it will load even in tight chambers. As mentioned in several of the prior posts, it sounds like your sizing die is not adjust down far enough to bump the shoulder.
I have 100 WSSM on my bench that I just resized. I had my gun out and actually sized them so they fit and the bolt just closed smoothly. I had adjusted the die per book when I loaded them the first time, as new, and a few of them were hard to chamber. This got me really upset because they were hunting rounds and I didn't need that in the field. I ended up having to sort them and the ones that were harder to close the bolt on were used for sighting in and plinking. This time I made sure I adjusted my die so every one of them chambers smoothly in MY gun.
I spray my brass with Dillon spray lube. I also have a little imperial sizing die wax on my index finger and as I place each brass into the press I wipe my finger across the mouth of the case. This leaves just a spec of lube inside the case mouth which is enough to make the decapping pin and/or sizing button slide in and out real smoothly.
Another suggestion is to seat your bullets per YOUR magazine or per your chamber/rifling. COL in the book is just a reference. It may not be optimum for your gun.
Good luck,
Steve