Air Rifle Research - Slugs vs Pellets

[DocUSMCRetired]

We are delving into the world of Air Rifles, have been for over a year now. We are developing systems and integrations into the AB Ecosystem that will include Air Rifles tools in the future. What I can share is limited but we are attaining some very good research material to be published later. With that being said, I can only share what you see here.

Air rifle slugs vs. pellets

Initial radar testing shows an interesting stability trend for slugs vs. pellets: drag is minimized for pellets in slower twist barrels, while drag of slugs is minimized for a faster twist.

Also, consistency of drag/BC is best when drag is minimized (BC maximized).

Attached are data for .300 caliber 44.5 grain Slug and .300 caliber 44.8 grain Pellet, both around 800 fps.

Experienced air rifle shooters told us to expect this so it's nice to see the measurements supporting this trend!

So why is fast twist good for slugs / bad for pellets and vice versa?

Air rifle pellets with a skirt are mostly drag-stabilized, not spin-stabilized. So, they don't need much if any spin at all to fly point forward; the skirt catches the air like the fins of a rocket. As such, spinning the pellets faster only becomes a problem of dynamic stability. If I had any suggestion after looking at this data, it would be to try an even slower twist for pellets, perhaps a 1:60" (one turn in 5 feet) or even 1:120".

Slugs are spin-stabilized so it reasons that more spin suppresses yaw and maximizes BC, to a point. Based on these results, it appears the slug is reaching max stability/BC with the 1:22" and the 1:18" provides no further benefit.

Again, these are just initial findings, we're eager to explore further in the coming weeks! To view our recent testing visit: https://thescienceofaccuracy.com/video/v023-getting-started-with-air-rifles-part-1/

If you would like to see further research or have any ideas please email us at [email protected]. Again I cannot share more than you see here.

 

[woogie_man]

Have been using Strelok for a while now and it isn't to bad for airguns. Though wouldn't mind trying something else for the airguns, espically with something that has a library for the different pellets and slugs out there. Then you can get into swaging your own slugs, or pellets, and really get the sizes and weights that you need down to the .01 of a grain! Being able to really fine tune the weight of the projectile, as well as being able to fine tune the exact blast of air behind the projectile really lends it self to some substantially accurate rifles!

I find that I am shooting my airguns much more than I do my fire arms!

Typically we will see that pellets like the 850-950 fps range for stability. For slugs we see that you can push them over the 1000 fps mark and still have great accuracy. I have found that some guns like to push slugs slower as well. Of course you will loose range, but the accuracy and the energy on target it much greater than a pellet of the same weight.

 

[steve123]

Doc, just wait until you try some of the higher BC Altaros slugs in the proper twist rates and power levels?!

I think it was a GA drag profile that fit pellets best, but I use G1, except oft I have to change parameters slightly to get the dope nearest to perfect. I still use the old SHOOTER app program but I might have to consider modernizing in the future.

 

[mikehotel]

Have been using Strelok for a while now and it isn't to bad for airguns. Though wouldn't mind trying something else for the airguns, espically with something that has a library for the different pellets and slugs out there. Then you can get into swaging your own slugs, or pellets, and really get the sizes and weights that you need down to the .01 of a grain! Being able to really fine tune the weight of the projectile, as well as being able to fine tune the exact blast of air behind the projectile really lends it self to some substantially accurate rifles!

I find that I am shooting my airguns much more than I do my fire arms!

Typically we will see that pellets like the 850-950 fps range for stability. For slugs we see that you can push them over the 1000 fps mark and still have great accuracy. I have found that some guns like to push slugs slower as well. Of course you will loose range, but the accuracy and the energy on target it much greater than a pellet of the same weight.

I use Strelok also, but you might try Hawke ChairGun pro mobile. It has a pretty good pellet library.