So, I did the unthinkable and headspaced off of a cartridge instead of a go gauge. I'm going to get a go gauge and do it right, but I wanted to break in the barrel today. The way I did it, I made sure that it was tight and there was no excessive headspace. And, I had a no-go gauge.

I intend to reload for the gun, and just bought a couple boxes of factory ammo to break it in, and get some brass fired in my chamber.

Because of that, I ran the headspace tight. The moral of the story is that some ammo loaded in easily and the bolt could just drop down to close. Some ammo, I could feel was tight closing the bolt.

Most interesting, 1 round would not chamber at all. They were all clearly within Sammi specs. But there was quite a variation. What probably made it a little more interesting was it was a belted Magnum.

So, this just goes to show that there is a reason Factory ammo doesn't group like real loads.