Should I be concerned that the primers have backed out a little on my fireform loads for 22 K Hornet?

I'm using 13.0 gr. Lil Gun behind Sierra 45 gr. Hornet #1200 with small rifle primers in a 77/22 Hornet. This load shot OK when the gun was regular Hornet.

Is this a sign of excessive headspace? Should I dump this brass and start over? Would it help to seat the bullet well into the lands?

Thanks in advance.

Yes, you HAD "excessive" headspace (more headspace than needed for the bolt to close easily) BEFORE you fired your .22 Hornet rounds in your K-chamber. Now, the headspace of your fired brass is perfect, provided you don't move the shoulder during reloading.

The regular Hornet headspaces on the rim, while the K-Hornet headspaces on the shoulder (or when shooting unfired brass, also on the rim).

The bolt on the 77-22H can be shimmed between the two halves to take up some of the initial headspace. You might want to consider this if your cases are stretching more than a comfortable amount on the initial firing.

If your fired cases are exhibiting more headspace than prior to rechambering, then it sounds like your gunsmith deepened the rim recess during the process. Shame on him.

Stonecreek,

Thanks for your reply.

How would I actually determine if I have more headspace know with the K Hornet chamber than I did with the regular Hornet chamber?

If I do what should I direct the gunsmith to do. He's a very good friend and competent gunsmith in my opinion but things happen I guess.

FWIW, I'd be talking to the gunsmith about this but he's currently on a missionary trip to Russia.

Clearwater.

What you might try is using a tapered expander to move the new Shoulder a bit further forward to allow the case to have a snug fit before firing, this should help the correct portions of the case to align in the new chamber.

Whoever cut the new chamber cut it too deep. It should still headspace adequately on the rim. While best accuracy with the K will occure with neck sized cases seating on the shoulder, the rim should be within spec for use with regular ammo. The rifle should be able to shoot regular or K's interchangably. If you fireform the case and it has a backed out primer, you then have a case with too short a shoulder length. (The case is gripping the wall and staying too far forward while expanding the shoulder area.) This wouldn't happen if the rim headspace were correct.

If you don't want to set the barrel back or adjust the bolt, I would fireform by lubing the cases really well to avoid wall grip and seating the bullet out into the lands with a slight reduction in load. This will hold the case in the proper position for forming. You should avoid regular Hornet loads with your chamber. I normally just shoot factory loads when I need new cases.