[Gbro]

I neck sized for my .257 Roberts for years and would have a little bolt closing interference that I never gave much thought to. Then when the Grand kids started using that rifle, well they had trouble chamber ing.
I then decided I had better FL size for them.
That worked well as for clambering but I found my brass was then to brittle and had case separation issues. Had to toss the whole lot of brass.

Loademwell;
I have closed my bolt on very tight loads due to neck sizing and have never had any trouble opening bolt before or after firing. The only time I had a bolt opening issue was when I had a extreme over pressure caused by my re sizing lube cementing the bullets into the cases on a batch that was a couple years on the self. I wasn't cleaning the lube out of case necks after I was Q tip ing necks with RCBS case lube., anyway, if I had your rifle in my hands I would make up a few dummy rounds and feel very carefully how the bolt handle feels closing. I am thinking you have a shoulder or indent in the locking lugs from some previouse issue or birth defect of the rifle, if you will.
If you have trouble opening the bolt handle with a dummy load chambered I guess you might bump the bolt forward with a soft block of some kind.
But in careful feeling of the bolt closing you should feel something.
Or visit a Gun Smith.