Another for the data base:Daisy 753 and 853 Lothar Walther barrel has 12 lands and grooves, 1:17.7” right-hand twist.
I have heard that the "trash can" shape JSB monsters in .177 don't perform well. I assume by the shape, that they are not as drag stabilized as a diabolo shape. Would a faster twist rate serve these pellets better or are they just a lost cause ? Do they need more of a spin stabilization ? How fast might they have to go to get proper stabilization ? Man, this is a fascinating hobby, so much to learn.
Most pellet gun barrels don't have much twist as compared to powder burning rifles.
Supersonic with an airgun is a fool's mission, IMO.... Even bullets have a 5-fold increase in drag through the Transonic region, and since we can't push them into the 2000 fps range with any practicality, they end up falling Subsonic as they travel downrange.... The physics occurring inside an airgun mean that to even approach Supersonic drops the efficiency to virtually unusable, so we spend huge quantities of air to get Supersonic, only to lose that extra velocity in the first few yards.... Additionally, the wind drift increases dramatically in the Transonic region as well, you get a lot less drift below 900 fps than above.... Combine all these factors, and you are FAR better to stay below 1000 fps (maybe 1050 with a really good bullet)….Bob
I think Tom Gaylord ran some tests on various twist rates from 1:12 to 1:20 on an airgun to see which one was optimal. Results indicated that 1:16 was the best. This was published in one of those gun newspapers like Shotgun News I believe. If anyone can find this article, it would be helpful to publish it here.