On the earlier thread I mentioned I would report the results of fireforming in my Contender 22 K-hornet barrel.
The barrel came yesterday. I made 2 sets of fireforming loads - one set had the neck/shoulder area annealed (before loading, of course!), and the other set was un-annealed. This Remington brass was once-fired in a regular Hornet.
I used loads with 40 and 45 gr bullets, and 296, 4227, Lil Gun, and Accurate 1680.
All of it worked fine. The shoulder was nicely formed and there were no splits whatsoever. No need to go through the work of annealing if it makes no difference.
The only slight difference was in the case length. The regular Hornet cases were 1.40" long. After fireforming, the annealed cases came out 1.39" long, while the un-annealed cases were a bit shorter at 1.38".