I am new to the list so please forgive me if I spew previously talked about information.
I have a CZ Hornet I had reamed out to a K-Hornet. Yes, the CZ has a tight barrel because the standard reamer pilot wouldn't fit in the barrel. I had to send the reamer out to get the pilot turned down to .223. The rifle shoots average 1/2 inch five shot groups at 100 yds going 3000 fps using lil'gun powder, forty grain .224 pills and small rifle primers.
If anyone wants to rent the K-Hornet reamer for their CZ, let me know. Why rent? No sense buying one and it will help me recoup some of the cost. It has only been used once.
I also have a pre 64 Mod 70 carbine in 22 Hornet. It went from 1 1/4 inch five shot groups at 100 yds to 1/2 inch averave when I switched to Lil'gun powder using Blitzking and V-Max 40 gr. bullets. I found a difference of 100 fps using small pistol primers vs small rifle primers, 3000 vs 3100.
Alll that being said, the CZ K-Hornet uses less Lil'gun powder because of the tight barrel to achieve the same velocity as the Hornet. I found little difference in accuracy between the .223 bullets and the .224 bullets in the CZ.
I have a friend with a Ruger 77 hornet and it doesn't shoot. We have run out of options without changing parts, ie new trigger, etc.