Quote Originally Posted by CROWMAN View Post
My Howa has a "trap door" magazine and I have been inserted them as I would with loaded rounds.

I'll try one just resting on top of the "trap door" plate and I'll try loading a dummy round with bullet inserted, that possibly could be the answer as loaded rounds I've tried chamber and eject fine.

I've just googled the problem and several people have stated that in their experience cases fired from another rifle never chamber at all or not well in another rifle due to headspace etc.

It's the first time I've had this problem with "once fired" cases, and it could be totally new cases from now on instead of a mixture.
cases from another rifle will chamber in yours when you full length size them as you take them back to saami spec.
they wont chamber if you only neck size them.
i set lee dies up by raising the ram fully then inserting die until it touches shell plate. lower ram them give the die another 1/4 turn ish......size then try etc
if you dont want the onced fired .223 i will take them etc