I decided to order some 19gr Nielson slugs to try with my Hatsan Flash .22. The results at 15 yards were interesting - they shoot just a little high, and to the right at 15 yards. Will be interesting to see the results over longer distances. I don't have any longer ranges nearby so it might be awhile before I get a chance to try it.
Tried the 19's, 21's, and 23's in .217 in my flash and flash pup .22. Noticed spiraling w all of them sadly... Tried in a few other guns as well and got quite a surprise with the 19's in my prod. This was 8 @ 25, and I can consistently hit a 1in spinner at 50 w it also!