Stiff Bolt on an SMLE - Need ideas

[CnRCollector]

I just received a Lithgow SMLE Mk III*. Without a round in the chamber the action is as slick as my Mk 4. However when I load a dummy round in the chamber action stiffens up quite a bit.
Cycling the action before pulling the trigger the bolt will open and eject the round with moderate force. When cycling the action after the trigger is pulled the bolt has to be slammed open. The force is so great the first time it happened I thought it was jammed. The both situations the round eject properly.
My guess is the strong force of the ejector spring is pushing the round against something and binding the mechanism somewhere.
Any one experience this? - Is there a way to fix it?

[Vlad 11]

Maybe a headspace issue or the dummy round isn't sized correctly?

[swifty]

I wouldn't change anything until you try factory ammo. If factory ammo is a problem then look into the problem.

[rojocorsa]

I say headspace or incorrect size for the dummy round.

Like swifty said, if it ****s up with factory ammo, then you got a problem.

[bruceflinch]

Try some factory ammo first.
The LE's are easy to adjust for headspace. Easy change of the bolt face.

[CnRCollector]

You guys were right. I reload 303 and neck resize only for my other Enfield to make the brass last longer. When I re-did some brass with the full length sizing die everything worked like it should. Glad is was not the gun. Facepalm!