Twist rate observation with pellets & wind drift

[mtnGhost]

I've spent the last few weekends tweaking and tuning my .30 FX Maverick Compact for pellets.

Something that I have observed with both 44 and 50 grain JSBs:

• They drift less in the wind with my 1:26" TJs than they do with the slower ~1:42-47"(?) 500mm Superior liner (having tested 3 different TJ barrels in this rifle thus far)
• All of the barrels shoot lights out in calm winds, but the faster twist rate REALLY helps keep them grouping tight when it's windy

When I had my Edgun R5 long, the 17.7" twist also seemed more desirable for the 50gr JSBs in terms of wind drift, compared to the FX Impact MKII (1:42" if I remember right) that I would shoot along side the R5.

Has anyone else had similar observations? Pellet ballistics are weird lol

 

[18.13]

The new superior heavy in .30 cal. is 1--22 that might be interesting.

 

[Centercut]

What I got from the article was that more spin cause more vertical jump. I couldn’t find where he talks about drift varying with spin rate.

https://hardairmagazine.com/ham-columns/vertical-deflection-for-pellets-in-crosswind/

Article on external ballistics of pellets, both trajectory and wind drift. 

https://hardairmagazine.com/ham-columns/the-external-ballistics-of-diabolo-pellets/

As far as real world experience, I’ve noticed when I had my .30 Bobcat with original ST barrel, effective twist rate approx 1:50, it wasn’t as affected by wind as the 1:17.7 twist rate Vulcan2 that I had with 44.75 JSB.

 

[mtnGhost]

What I got from the article was that more spin cause more vertical jump. I couldn’t find where he talks about drift varying with spin rate.

https://hardairmagazine.com/ham-columns/vertical-deflection-for-pellets-in-crosswind/

Article on external ballistics of pellets, both trajectory and wind drift. 

https://hardairmagazine.com/ham-columns/the-external-ballistics-of-diabolo-pellets/

As far as real world experience, I’ve noticed when I had my .30 Bobcat with original ST barrel, effective twist rate approx 1:50, it wasn’t as affected by wind as the 1:17.7 twist rate Vulcan2 that I had with 44.75 JSB.

That kind of aligns with my experiences. I couldn't take accurate shots on breezy days with 44gr JSBs past 50-60y using the R5 (2.5-3" groups) - yet, I had very impressive results shooting them in similar conditions with my EVOL where they were stacking consistently not more than 1.5" at 830fps over 100y (minus the random bad pellet shot from a tin drenched in silicone spray). 

Oddly, the 44gr shoot noticeably better in the FX barrel in my Maverick than any of the (3) TJs that I have setup for it on calmer days. The TJs seem a little more predictable shooting them in the wind though, and they undoubtedly prefer 50gr (which are decent with my Maverick FX liners on calmer days, and not too great when the wind starts howling). 

The new superior heavy in .30 cal. is 1--22 that might be interesting.

I'm pretty anxious to see how much better they are than the Superior with 50gr. I love these TJ barrels, but they're a little heavier being solid CrMoly, and I'm always looking for ways to reduce rifle weight for field use. I have to push the 50's pretty fast with 1:26" twist (the closer I can get them in the lo 900's the better), so I'd like to see how slow I could shoot them before accuracy goes out to lunch with the Heavy liner.