Ballistic Theory Same Weight Slug and Pellet - Slug Is Slower - Why?

[Billm]

Bill i think your getting obsessed with this and need to just wait till you can shoot. Prepare sample slugs that you have fill the gun with air and a tank if you have and wait to shoot oh make some paper targets and mark down what was shot and how the gun was set up so you remember. Let the targets tell you whats going on

You’re right lol. I don’t have a tank, I need to get one, I can see the convenience that they provide.

 

[Danman]

I may purchase the dies for .30 hybrid dies. The bearing surface on a .30 Ho dish base under 52gr is relatively short and basically I would guess that maybe 25% or less of the length of the slug is in contact with the barrel. Pthe contact is only in the rear of the slug. It’s conjecture, but it’s hard to believe that only rear contact doesn’t induce yaw or pitch. Not exactly in line with the thread topic, but relevant I think. The hybrids allow a larger bearing surface with a lower weight. I haven’t tried hybrid slugs, but maybe I will before buying more dies. Herein lies my issue with the Sonoran: any regulars slug over 52gr is going to be dropping below 800fps. Getting a 52gr slug to 850fps at max power is borderline. What is fast enough for .30 slugs at 100yds, I don’t really know?

Remind us @Billm ...what is max fpe of the Sonoran? 90fpe? The Ghost with the big boy (28in) .30cal barrel easily hits above what Brk says on their website (110fpe) And then there is the black Wolf, easily laying down 130fpe+ in .30. Clearly you are wanting to make your own .30cal slugs but the Sonoran is NOT the gun for the job here imo.
My advice: build the ammo you want, spec the gun that will shoot it to speeds you want/need. Sell Sonoran (or keep it as pellets only) and grab a meaner .30cal that fits your criteria. I have the .22 Hybrids.... like them alot, longer body compared to any of my other similar weighted slugs! Just quite expensive vs the other brands

 

[Billm]

Remind us @Billm ...what is max fpe of the Sonoran? 90fpe? The Ghost with the big boy (28in) .30cal barrel easily hits above what Brk says on their website (110fpe) And then there is the black Wolf, easily laying down 130fpe+ in .30. Clearly you are wanting to make your own .30cal slugs but the Sonoran is NOT the gun for the job here imo.
My advice: build the ammo you want, spec the gun that will shoot it to speeds you want/need. Sell Sonoran (or keep it as pellets only) and grab a meaner .30cal that fits your criteria. I have the .22 Hybrids.... like them alot, longer body compared to any of my other similar weighted slugs! Just quite expensive vs the other brands

Well when I bought the Sonoran the product description stated 90fpe. It also stated that in the AOA 100yd test video. But, when half the comments on the YouTube video were calling out their math, the description was changed to 85fpe . That’s with the power tune. I think you’re right. Another rifle. I don’t think I will sell it. But, I will buy a more powerful rifle. I was seriously considering buying a Black Wolf, but, I’m holding back on that, there’s too many people questioning it’s accuracy for the price. If they would’ve let me return it towards a Black Wolf Chassis, I would’ve bit the bullet. I really should’ve skipped the press lol. I’ve got enough lead for 8000 52gr .30 slugs. LOL. My wife surprised me and watched the videos about swaging and told me to buy the Western Big Horn press. Sure glad I ignored that advice lol. I’m already waiting for her to ask me why I keep ordering pellets, when I have all this lead . I have considered buying a barrel for the Ghost, but in .22. I’m hoping the polishing has helped the new Sonoran barrel. My first groups with the new barrel almost always had a flyer as much as 4” away from the main group. After the polishing those flyers have disappeared with pellets at 75yds. I haven’t shot any slugs yet since the polishing. The first barrel was very accurate but would quickly foul and really open up.

 

[Solo1]

If you watch any vids that jared does you would understand the 90 fpe thing he always upgrades a bit. Bill is there a reason fot a 100 fpe gun?

 

[Billm]

If you watch any vids that jared does you would understand the 90 fpe thing he always upgrades a bit. Bill is there a reason fot a 100 fpe gun?

That’s a trick question lol, you know shooting in my backyard, I don’t really have a need for 100fpe .

 

[Franklink]

That’s a trick question lol, you know shooting in my backyard, I don’t really have a need for 100fpe .

I hear the typical cedar plank yard fence and/or the vinyl plastic yard fences are great backstops for 100fpe.

At least with .30, the holes will be big enough to maybe pass for knotholes in the cedar plank fence.

 

[Billm]

I hear the typical cedar plank yard fence and/or the vinyl plastic yard fences are great backstops for 100fpe.

At least with .30, the holes will be big enough to maybe pass for knotholes in the cedar plank fence.

I have shot through a 2x4 on the long side with it at Around 85fpe. I don’t have a back fence loI. I use a 3/16 steel plate for most of my shooting. Followed by 600,000 acres of public hunting land behind my property. The bottom of my target stand has a galvanized steel sheet over 5/8” cedar and I’ve punched through that 3 or 4 times, but only at 50yds or less and I usually shoot at 100yds. I’m getting ready to put up 12-20’ length of double sided fence with filler in between at the end of my property to catch any errant flyers. I’m comfortable with .30 and below, if I purchase any big bores, I’ll have to put a berm in. The .30 did a number on my rim fire trap at 35yds lol.

 

[PapaT]

18-24" of rubber mulch have served me for my .457.

 

[Billm]

18-24" of rubber mulch have served me for my .457.

I’ll keep that in mind. Eventually I’m going to put up a 24”x48”x1/4” steel plate.

 

[Cantona256]

It’s 100% due to the increased friction of the bearing surface. Pellets don’t have much contact surface in the barrel and that’s by design. Pellets need only a minimal amount of spin which is why Fx does the “smooth twist” on the pellet liners. The pellet skirt flairs when hit with the HPA to form the seal and off it goes. My karma EQ needs .3025 or .303 slugs to shoot slugs properly but it shoots any .30 pellet I want very accurately. Even with the skirt flairing there’s no way the undersized pellets are sealing the barrel to the same extent a properly sized slug will.

Slugs absolutely need to be spun and thus have a larger bearing surface to engage the rifling. Some slug makers I’ve worked with have been very particular as to the minimum amount of bearing surface a slug needs. That’s why certain slugs can’t be made at less than a certain amount of grains. For example one slug I’ve tried is a 71gr hybrid boattail. Slug maker won’t do lighter because the amount of bearing surface is already at the minimum level…

So with the increased friction you will get less fps.

It does not have to do with the seal because if you’re using a properly sized slug the seal you get should be as good if not better than the pellet. For example, I just ordered a .30 cal barrel from Lothar Walther. Going through the specs I saw the groove diameter is actually .306… so I emailed Lothar until the actual head of Operations John McBrayer sent me an email saying:

“With a groove diameter of .306, I would start with a .307 or .308 slug. You need a good seal, so this is probably the best place to start. This should keep the slug from being too loose or too tight.”

So as you can see the barrel maker themselves is actually advocating a slightly oversized slug for a proper seal.

It’s just friction in the barrel because once out of the barrel the slug is about 10000000x more aerodynamic than the pellets are

 

[Billm]

It’s 100% due to the increased friction of the bearing surface. Pellets don’t have much contact surface in the barrel and that’s by design. Pellets need only a minimal amount of spin which is why Fx does the “smooth twist” on the pellet liners. The pellet skirt flairs when hit with the HPA to form the seal and off it goes. My karma EQ needs .3025 or .303 slugs to shoot slugs properly but it shoots any .30 pellet I want very accurately. Even with the skirt flairing there’s no way the undersized pellets are sealing the barrel to the same extent a properly sized slug will.

Slugs absolutely need to be spun and thus have a larger bearing surface to engage the rifling. Some slug makers I’ve worked with have been very particular as to the minimum amount of bearing surface a slug needs. That’s why certain slugs can’t be made at less than a certain amount of grains. For example one slug I’ve tried is a 71gr hybrid boattail. Slug maker won’t do lighter because the amount of bearing surface is already at the minimum level…

So with the increased friction you will get less fps.

It does not have to do with the seal because if you’re using a properly sized slug the seal you get should be as good if not better than the pellet. For example, I just ordered a .30 cal barrel from Lothar Walther. Going through the specs I saw the groove diameter is actually .306… so I emailed Lothar until the actual head of Operations John McBrayer sent me an email saying:

“With a groove diameter of .306, I would start with a .307 or .308 slug. You need a good seal, so this is probably the best place to start. This should keep the slug from being too loose or too tight.”

So as you can see the barrel maker themselves is actually advocating a slightly oversized slug for a proper seal.

It’s just friction in the barrel because once out of the barrel the slug is about 10000000x more aerodynamic than the pellets are

I think you will find that the minimum length of the bearing surface has more to do with the balance of pressure and cg of the slug, rather than the seal.

 

[Cantona256]

I think you will find that the minimum length of the bearing surface has more to do with the balance of pressure and cg of the slug, rather than the seal.

Yeah the bearing surface on a slug is so that it engages the rifling properly so that it gets spun correctly… I was pointing out that a properly sized slug won’t seal the barrel less than a pellet.