Slugs / Bullets

[oldsparky]

I haven’t been bitten by the slug bug yet. But have some questions. I have cast bullets for years so I understand how a bullet in a firearm works. As a correctly sized bullet it is fired it obdurates and seals the barrel from gasses passing by the bullet. I hear a diablo pellet skirt is a larger diameter than the head and seals the barrel when it is pushed into the barrel via the pellet probe. My question is, does a slug seal with the same principle as a diablo pellet? Is that why the base is cupped? What started this thinking is I wondered why slugs are shot rather than bullets. Any discussion would be helpful. 



thanks, Sparky

 

[TNT19]

Hey oldsparky. Just my 2 cents on your post. I am a powder burner peep for 38 years and have done some reloading myself. I recently dipped a toe into the airgun slug pool and noticed the slug tends to create a tighter seal as there is more surface area touching in the barrel. I have a mid level pcp that I modified for more power and was able to get the NSA 17.5 gr .216 slugs in 22 going about 890 to 900 fps and achieved some amazing results. I recently purchased a high level pcp that will be able to push slugs in 22, 25, and 30 caliber at a respectable fps. I also noticed when I went back to the pellets my poi drastically changed 

 

[AirSupply]

For the FX hybrid slugs I’d say yes for sure that is the “hybrid” part of the slug. That is the ability for the rear to expand and seal. That and the lighter weight for its overall length . They seem to work in a wider variety of barrels and velocities. 
Plenty of guys have had great results with flat based slugs so they don’t have to expand to seal to work well. They do have to be the right diameter. That’s for sure. 
Michael

 

[Xbowsniper]

Oldsparky,

As the gentlemen above said, it's all about barrel fit.

When I decided to dive into swaging slugs, I did it backwards. I told the diemaker that I wanted 4.52mm, and 4.53mm, because that's the size pellets most of my guns liked. When I received the dies, and made my projectiles, I was very impressed with their consistency and uniformity. Then I shot them. Never shot anything this bad in any of my guns. Ever. The best groups I could get at 30 yards, was about 8 inches, if I was lucky.

I then contacted the die maker, and upon his recommendation, wanted me to send him pellets shot out of a couple of rifles. I chose my RAW TM1000, and my Steyr LG 110 FT, both at 12 ft.lb. I shot several dozen out of each, sent them to him, and he inspected them under a microscope used for precision measuring. He determined that my size was .1775, which is considerably smaller than the 4.52 that I initially started with. 

Fast forward to today, and I can safely say that the newer dies are perfect, and my results have shown that. Being that the lockdown has me handcuffed until my range opens, I can't really test my different designs and weights properly.

That being said, they shoot halfway decent through most of my guns, I need to tinker with weights and base shapes in order to have a better projectile for Field Target competition. 

Tom Holland 

Field Target Tech 

Fieldtargettech.com 

 

[bandg]

I'll venture a couple of poorly informed ideas. It seems that the slug would need to be either much more accurately sized to the barrel (land and groove depth could also be in play) or softer where a slightly larger size could be pressed in to seal the bore in order for them to function as well as a pellet mechanically (aerodynamic advantage not considered). Airguns have much less energy to drive the projectile than any firearm and they generally don't have the robust action able to seat the projectile into the leade. Any leakage past the projectile due to poor seal in the bore would seem to be a major drawback to the concept. Similarly, their much lower energy levels would be more sensitive to variations in or additional drag from larger contact area of a traditional "slug". It's amazing to me that people have been able to make it work as well as it has and it is a testament to those who've done the work involved. My air gun shooting is perfectly well served by pellets and I have plenty of firearm options to step up to if more is needed. But I do appreciate the effort by others to make the slugs work for air guns. Very interesting.

 

[mercado]

Manly I imagine that slugs weight could be more easy to control in a slug versus bullets maybe are easier to design..but my cricket shoots cast bullets 25 acp better than anything else on the market...that's why I don't believe in half the BS such expert says I keep trying other things..better that keep collecting every one's slugs .that only work for close shots.. unless you have the 2k gun ..I order a 4 cavity solid and 3 cavity HP .. and ask the mold dimensions to be down sized to .217 if that one works as good as the. 25 .. slugs buying is over for me ..