I have a tang saftey Ruger in a swift thats got me puzzled. Normally I full length size this round but recently bought a neck sizer.Before and After neck sizing the round will not chamber. Brass has only been loaded once and not a hot load at all.If I FL size bolt closes slick.I called Ruger to ask them and they said just shoot factory loads....( to release them from any possible issues with reloads.)

Ive been reloading for over 20 years and have never run into this.Any ideas as what might be going on? Tight chamber? Brass is Winchester.

It could be an out of round chamber or one not aligned with the bore. The case is formed to it and will not go back in unless exactly aligned with the way it came out.
A barrel not screwed in straight to the reciever will also cause it.