My K-hornet shoots factory hornet or reloaded hornet ammo extremely well. I would almost say it shoots hornet rounds the same as it did before the reaming. You do loose a few feet of velocity due to case "fire-forming", but I have noticed no difference in accuracy. The k-hornets does shoot higher due to the increase in velocity so you can't expect the same zero out of both.

Benifits of the k-hornet: longer case life, more case capacity, and increased accuracy. I can now cloverleaf three shot groups, covering it with a dime at 100yards. Before the reaming I could only do about 1 inch or so at 100yards.

Accuracy comes because the k-hornet headspaces on the new shoulder instead of the rim of the case.

As for fireforming, if I don't shoot factory ammo I just buy the cheapest components I can find to load hornet rounds. I have heard of people packing grits over powder instead of a bullet to fireform but I wouldn't trust it.