FOLKS,
I have a 20" SS Contender barrel made by BULLBERRY in 22K HORNET.
When I was fireforming brass it was shooting SUB MOA. Now with the proper brass loaded with 12gr of LIL-GUN & a 35gr VMAX - my groups are opened to 1.5".
I know this barrel shoots..it has to be something I'm doing. I use the Redding Deluxe die set ( FL-NK-SEAT.). Perhaps I should only neck size ??? Please keep in mind BULLBERRY cuts a VERY TIGHT CHAMBER. This was Fred Smiths barrel -he donated it to the TCA for their 20th Anniversary bash & I won it in a raffle.
Got any ideas , it shot sub moa at the bash !!
Thank you in advance for your time & help.
SOUP

Now that you've fireformed the cases, have you tried a little more powder? I shoot 13.5 grains of Lil-Gun with 40 gr. bullets out of my Ruger 77-22H (not K).

Did you work-up to that load you are complaining about, or did you just grab one load out the the thin air and decided that is what you want?

I think Steve has your problem. What bullet shot the small groups? what OAL was it loaded to? What powder was used?
Change anything and the load/firarm performs different.

Don't forget small pistol primers too.