Bolt Sticking

[50 Calshtr]

Guys,
    I have an old 303 built on a Steyr 1893 action.  When I had the headspace checked it was OK but when I fire it the reloaded rounds chamber easily but after firing the bolt shows some resistance in opening.  I'm shooting 180 gr bullets at the low end of the loading tables, trying for about 2050-2100 fps to match the original 1895 - 1900 era loads.  My gunsmith says these lower loads are the problem, not causing the case to expand enough to grip the chamber and jamming back against the bolt causing the hard opening. Does this sound reasonable?  I don't want to hot-rod this old rifle as it's a nice example of the period.
Thanks.

[Nobade]

There are quite a few things that could be going on there. The first thing that comes to mind is the finish inside the chamber. What do the cases look like after they're fired? Any scuffed places you can see? What is the diameter of the throat and the bore in relation to the bullets you're using? What load are you using? What does it do with factory ammo? There are plenty of places to look, be thorough and you're sure to spot the problem.