Slugs

[ballisticboy]

B) if slugs are developed for sub 12ftlb market they are unlikely to offer a major advantage over diablo pellets to justify development costs


Rich.

The main advantages would be much reduced wind response and reduced need for pellet/barrel matching due to the slugs being ballistically more tolerant of launch problems.

[averageplinker]

The main advantages would be much reduced wind response and reduced need for pellet/barrel matching due to the slugs being ballistically more tolerant of launch problems.

Every day is a school day 😀

[krisko]

I will repeat it.
if have got a gun setup to shoot heavy pellets, at certain speed. I am positive that if you use a slug with the exact same heavy weight as the pellet, due to friction the slug will have lot less FPS already at the muzzle! There is someBC advantage yes but not that good result overall as many may think really. YouTube attention seekers and influencer are popular these days yes.

you will have to up the tune a lot, that costs loads of air I.e. shotcount. Plus it can easily wreck your gun/some guns, definitely putting more strain on components.

Regarding all the modelling and ballistic software:
Again I have seen comparisons when people use chairgun and that one maintains the same zero, basically you can’t compare 2 different projectiles like that at all. It will result in loopier trajectory as chairgun points to barrel up towards the sky to keep the zero, then people think look the drop is not too bad at far distance.

Man you have to keep the POA and just shoot with both projectiles in real life to assess performance.


Anyway slugs don’t come anywhere close to pellets in precision. Power is nothing if you miss, pellets are self homing lol

[the growler]

My theoben rapid is set up for Fac and it shoots the slugs faster than the diablo pellets.

But slugs would still be only of use for fac guns. Diablo still do the business at normal hunting distances.

Slugs definitely kill better with a nice hollow point. See what comes out of h&n and jsb.

[ballisticboy]

I will repeat it.
if have got a gun setup to shoot heavy pellets, at certain speed. I am positive that if you use a slug with the exact same heavy weight as the pellet, due to friction the slug will have lot less FPS already at the muzzle! There is someBC advantage yes but not that good result overall as many may think really. YouTube attention seekers and influencer are popular these days yes.

you will have to up the tune a lot, that costs loads of air I.e. shotcount. Plus it can easily wreck your gun/some guns, definitely putting more strain on components.

Regarding all the modelling and ballistic software:
Again I have seen comparisons when people use chairgun and that one maintains the same zero, basically you can’t compare 2 different projectiles like that at all. It will result in loopier trajectory as chairgun points to barrel up towards the sky to keep the zero, then people think look the drop is not too bad at far distance.

Man you have to keep the POA and just shoot with both projectiles in real life to assess performance.


Anyway slugs don’t come anywhere close to pellets in precision. Power is nothing if you miss, pellets are self homing lol

There is absolutely no reason at all why the friction drag on a properly designed airgun slug will be any higher than it is for a pellet in a barrel. They will both have the same bearing surface material and bearing area so friction is a none issue.
Chairgun is a useful tool for initial settings on a gun but it is not, and never has been intended to be, a scientific tool for projectile design and comparison. If you want to do that you need a far more complex model than Chairgun has ever been along with input data which is simply not available to most shooters. A properly designed slug, the same weight and muzzle velocity as a pellet, will have a flatter trajectory than the pellet, not more curved, due to the lower drag. If you want to keep the same POA then the slug would have to have the same brick like aerodynamics as a pellet so there would be no point in having them.
You need to try not to generalise based on poorly engineered previous efforts and YouTube heroes. What I am saying is based not just on theory and modelling but on practical experimental experience from 30 years ago.
However I will say that what I have seen of the big pellet makers attempts so far at designing slugs have appeared little better than the amateur designs.

[the growler]

There is absolutely no reason at all why the friction drag on a properly designed airgun slug will be any higher than it is for a pellet in a barrel. They will both have the same bearing surface material and bearing area so friction is a none issue.
Chairgun is a useful tool for initial settings on a gun but it is not, and never has been intended to be, a scientific tool for projectile design and comparison. If you want to do that you need a far more complex model than Chairgun has ever been along with input data which is simply not available to most shooters. A properly designed slug, the same weight and muzzle velocity as a pellet, will have a flatter trajectory than the pellet, not more curved, due to the lower drag. If you want to keep the same POA then the slug would have to have the same brick like aerodynamics as a pellet so there would be no point in having them.
You need to try not to generalise based on poorly engineered previous efforts and YouTube heroes. What I am saying is based not just on theory and modelling but on practical experimental experience from 30 years ago.
However I will say that what I have seen of the big pellet makers attempts so far at designing slugs have appeared little better than the amateur designs.

The Nielsen slugs only contact barrel on the rear third of the slug. These pellets are far superior than the rabbit magnum, piledriver etc

[ballisticboy]

The Nielsen slugs only contact barrel on the rear third of the slug. These pellets are far superior than the rabbit magnum, piledriver etc

They are still based on the 9mm bullet type shape and rather heavy for sub 12FPE guns. The shape is a peculiar mixture of high drag hole combined with a long nose shape suitable for speeds around 1500ft/sec which the pellet will soon slow down past even if it starts out much faster.

[the growler]

Yes. Slugs only for fac for me.

[arnie2b]

There was a time when people tried every available .25 bullet mold available with every available barrel twist rate to no avail.
The 257 mold yield results.

There are people shooting 222/223 slugs with some sort of succes.

Interesting to see what will happen in the future regarding airgun slug development.

[krisko]

There is absolutely no reason at all why the friction drag on a properly designed airgun slug will be any higher than it is for a pellet in a barrel. They will both have the same bearing surface material and bearing area so friction is a none issue.
Chairgun is a useful tool for initial settings on a gun but it is not, and never has been intended to be, a scientific tool for projectile design and comparison. If you want to do that you need a far more complex model than Chairgun has ever been along with input data which is simply not available to most shooters. A properly designed slug, the same weight and muzzle velocity as a pellet, will have a flatter trajectory than the pellet, not more curved, due to the lower drag. If you want to keep the same POA then the slug would have to have the same brick like aerodynamics as a pellet so there would be no point in having them.
You need to try not to generalise based on poorly engineered previous efforts and YouTube heroes. What I am saying is based not just on theory and modelling but on practical experimental experience from 30 years ago.
However I will say that what I have seen of the big pellet makers attempts so far at designing slugs have appeared little better than the amateur designs.

A pellet barely contacts the barrel, slugs have 10x more surface to rub against, some designs have thin rings to seal mimicking pellet style contact.

[eyebull]

Is the big difference between diabolo and slug type pellets not that diabolos are more suited to sub-sonic speeds, and slugs to trans- and super-sonic?
If this is the case it may be why only very powerful airguns (+/- 1125 FPS) really see the benefit from slugs?

[ballisticboy]

A pellet barely contacts the barrel, slugs have 10x more surface to rub against, some designs have thin rings to seal mimicking pellet style contact.

Pellets contact the barrel at the maximum diameter point on the head and at the base of the flare. There is no reason on earth why slugs should not do the same if they are properly designed. 155mm shells do not have the entire side in contact with the barrel and there is no reason a slug should do either. Your assertion that slugs have 10x more surface area is only true for a poorly designed slug based on bullets and not optimised for air guns. If you look at my avatar on other forums you will see a slug with minimal barrel contact area.

Is the big difference between diabolo and slug type pellets not that diabolos are more suited to sub-sonic speeds, and slugs to trans- and super-sonic?
If this is the case it may be why only very powerful airguns (+/- 1125 FPS) really see the benefit from slugs?

Diabolos are more suited to smooth bore which is probably where they originated. There is no reason why aerodynamically subsonic projectiles should be a diabolo shape.

[eyebull]

Diabolos are more suited to smooth bore which is probably where they originated. There is no reason why aerodynamically subsonic projectiles should be a diabolo shape.

Given that a decent diabolo in a decent barrel is capable of one-hole groups at 40 yards, how much more accuracy should we expect?

[the growler]

Given that a decent diabolo in a decent barrel is capable of one-hole groups at 40 yards, how much more accuracy should we expect?

Slugs are more for longer range fac power. Nothing wrong with standard pellets at moderate ranges. Slugs more like a mini .22lr bullet. With a good hollow point. They do mushroom on impact. As I am using them. Got them in .25 and .30. yet to try them though.

[ballisticboy]

Given that a decent diabolo in a decent barrel is capable of one-hole groups at 40 yards, how much more accuracy should we expect?

Diabolos will only give you a one hole group at 40 yards if you have managed to find the correct batch number and there is no wind blowing. But if you are happy to use the ammunition equivalent of a Model T Ford in your gun, albeit a well made Model T Ford, then that is fine. Other people are not.