Couple of things...
As Bogie mentioned, make sure the bolt and all bolt internals are cleaned & lubed.
Also, remember that the M-N cocks on opening the bolt...and that is one heck-for-stiff firing pin spring in there. I have heard of folks taking a couple of coils off that spring, but I have not tried it.
Was gonna say something about making sure the chamber is clean and un-pitted, but you mentioned 'dry fire'...no ammo, so that is not the issue here.
When I first got my M-44, there was so much cosmo in the barrel, I thought it had been 'shot out to smooth', plus it wouldn't even chamber a round. I soaked the bolt in mineral spirits for 2 days, plus used a 'hot-air' gun {heat-shrink tubing blower} to melt out the last of the cosmo. I would heat up the bolt with the hot-air gun till I could barely hold it, then drop it in the pan of mineral spirits....repeat