Yes the chamber could be too tight. Sometimes you get a minimum tolerance chamber paired with a maximum tolerance die. If that's the problem, some suggestions are:
1. Contact the die maker. Usually, they will remedy the problem for free if you send them your full length resizing die and a fired case.
2. Buy a small base resizing die.
3. Grind about .005 inches off the face of the shell holder. Then adjust the sizing die down, until the resized case JUST chambers easily in the rifle. Remember that headspace will always have to be manually adjusted when you use that shell holder for other rifles or that rifle.
4. Buy another resizing die and hope you get lucky, and I'm not being snarky. Everyone has their favorite die maker, but I've always had the best luck with Redding dies.