types of skirts in slugs

[joselitovillasboas]

Hi, my name is Joselito, I from to Brazil.

I was doing some tests with slugs with 3 types of skirt, concave, straight and diahbase, but so far I haven't reached an exact conclusion regarding what really changes depending on the skirt.

Can someone explain to me in a more technical way if there is any change and what effects each skirt provides.

 

[JungleShooter]

One thing that CAN change is the seating depth of the slug in the barrel:
straight or flat base = deeper seating
≠
concave base = less deep seating


Saludos del Perú,

Matthias

 

[Engg.Ken]

What gun are you shooting slugs from @joselitovillasboas ?

 

[subscriber]

What gun are you shooting slugs from @joselitovillasboas ?

Good question, Ken. Some airguns have a pin probe, and some have a partial tube probe. The pin type is more likely to alter the seating depth between different projectile base configurations.

Joselito; As for pellets with a flared skirt, VS slugs or bullets with a flat base; their aerodynamics are different. Slugs need a faster rifling twist in the barrel than pellets. Meaning 1:16 twist in .22 caliber is good for slugs up to 40 grains, while also faster than pellets need for shooting smallest groups; especially as range increases.

Shooting heavy slugs with too slow a twist barrel will tend to have the projectile yaw and then tumble, to cut long holes in the target, rather than round. Grouping ability will be very poor under such conditions. Pellets can shoot well using very slow twist rate barrels (or even smooth bores), providing there is an effective air stripper at the muzzle to prevent the initial air blast as the pellet leaves the muzzle from upsetting its flight.