Brand new CZ 550, FS, 6.5X55.
The first thing was attempting to move safety to the safe position, almost impossible.
A bit of work with a slip stone cured this.
Next: Loaded magazine, great difficulty in loading 4th and 5th rounds.
Would not feed.
I figured the follower spring had waaay too much tension, compared to my 96' carbine, yes about twice as strong.

A run to my gunsmith secured another spring, all is good.
It was a "vocabulary enhancing experience"
I have three .22's with out problems, so i think it was the fickle finger of fate.