I agree with Bill.
I FL re-size and would stick with bullets under 50Gr's. The hornet made its mark with 2400 and its still an excellent choice of powder for it!! Lil Gun is a new one but showing much promice in the Lil hornet case.
You will see, but handling the little hornet cases takes a bit more care as that neck is mighty thin. Its not a difficult one to load for once you realize its one issue. (those necks)
I had thatbarrel and did some excellent chuck eradication with it. It is also the caliber I used for my longest pistol shot. About 240-250 yards on a coyote. Quick story:
I was woodchuck hunting in the spring and in a field where I knew a big fat chuck frequented. After a short time he came out and was sitting up eating looking to my left. I was lying prone about 140 yards distant. I aimed right at the top of his head and squeezed off. He just sat there, never moving. I quickly reloaded and got ready to shoot again, when I knoticed movement in the trees to my left. It was a coyote stalking my chuck!! I had no shot until he entered the field at the bottom. He was still, I pout the crosshairs just over his back and squeezed off again. This time I herd the "plop" as the little bullet struck. He wheeled and ran back to where I first saw him about 100yards to my left and piled up. I hit him just right, just under the spine but high in the lungs pass thru. I guess because of the distance the bullet didn't come appart, no bones hit IIRC. back to that chuck, I didn't miss. As a matter of fact I hit him just under the chin, breaking the neck and exiting. He was so freaking fat, he didn't even fall over, he looked line a furry "jaba-the-hut" from star wars fame!!!
You will have allot of fun with this barrel. Good luck with it!!
CW