slug design concept: 1) lubed 2) paper patched.

[catboat]

Group buy idea for a shotgun mold?

Not sure about dimensions, but here is the concept (it can be applied to 12 or 20 gauge, but I'll work around 12 gauge for now).

Design for rifled 12 gauge slug barrels.

Lee "tumble lube" style grooves. This will allow easy (low cost) liquid alox lubing for direct slug/bore contact (like a "regular" cast bullet), no need for a shot cup.

Hollow point: about 1/4" diameter, about 3/8" deep (but may not be needed).

truncated nose (maybe 1/8" to 1/4" high with ~ 0.5" flat meplat perhaps more accurately called "a plateau with a hole in it"), with a 90 step from bore to the base of the "plateau" (truncated nose) with a flat ring (perpendicular to the bore, sort of like an exaggerated "Keith style" step, ) that would be .73-.5"= ~ .18-.20/2 or ~ 0.10" flat concentric ring on the front of the bullet, before the "plateau" starts.

Cast diameter , from wheelweights at 0.001-0.002" over bore size ( ~ 0.731?)

Weight: 1.25 oz or thereabouts?

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option 2

Paper patched slug (avoids need for shotcup or lube)

Similar design, except, not hollow pointed, but HOLLOW BASED (to tuck / fold end of paper into.

Diameter would be about 0.006-0.008" under bore size of a rifled slug barrel (to allow for two wraps of paper to make up the difference in diameter, just like rifle paper patched bullets.

Hollow Base: Not a thin, flimsy skirt that will compress under powder detonation. A big thick skirts, at least 0.25" thick and the hollow cavity about 0.25-0.375" deep.

Nose: similar "flat truncated plateau" as above. No hollow point, as the handles would be on more important hollow base pin.

Weight: about the same;at least 1 oz, hopefully 1 1/8 to 1.25 oz of slightly heavier.


-------------------------------

20 ga: similar concept. Tumble lube at 0.002" over bore diameter for non-paper patched version, with hollow point

and paper patched version, with not hollow point, but with stout-skirted hollow base (with tumble lube grooves to hold patching), .006-0.008" under bore diameter (to allow for 2 wraps of paper).

-------------------------------

Comments? Input?

[longbow]

A little food for thought.

I've paper patched the Lyman 12 ga. Foster slug to bring it up to bore size with mixed results.

The slug as cast is considerably undersized so I thought paper patching to bore size would help minimize uneven obturation. Generally accuracy from my smoothbore improved somewhat but I still got flyers ~ bad ones. After working with the paper patching and other bore size moulds I began to wonder if the paper was not liking the roll crimp. I get better accuracy with a bore size RB than the paper patched Lyman slug.

Personally I would stickwith bore size and lube. However, since I don't have a rifled gun I won't be part of this group buy.

Like I said, just food for thought. Maybe worth some testing before getting moulds made if the paper patching route is popular.

Longbow

[crowbeaner]

I'd be happy if Lee would make the Key drive slug mic at about .715. I could add card wads to make up the difference in heighth and roll crimp to keep the chamber pressure in line. Anybody think that would work?

[missionary5155]

Just another thought... What performance can you gain over a Round Ball ? I have yet to see a SLUG that will out penetrate a round ball. Get a Dixie mold or any mold about .685 and you can dump the shot and drop in a ball (spur up) reclose the shell and you are ready to roll. All rifle barrels will stabalize it.
Or get a bore size round ball. Again it will out perform any slug

[tommygirlMT]

I'd be happy if Lee would make the Key drive slug mic at about .715. I could add card wads to make up the difference in heighth and roll crimp to keep the chamber pressure in line. Anybody think that would work?

You would be better off with a diameter of 0.727"-0.730" (that's what you tell the machinist that's limit style dimensioning/tolerances) and cast of pure lead or darn close for everything but rifled and cylinder bore (anything with choke must be soft lead). It's not difficult at all to lathe bore out the Lee mold to full bore diameter. In fact I bored mine out extensively to work for my 10ga. I put tumble lube type grooves in mine but flat sided would work just fine too. Another trick that works good and most machinest smile at and say "sure that's easy" (that's good because that means they are going to charge you less $$) is to simply have them take an internal thread cutter attachment and set their lathe up to spin the inside of the slug mold out like they were threading a fine thread nut. Done to the proper diameter this will give you some very good tumble lube grooves. Just make sure they don't F%&* up the core pin seating ring on the Lee mold.

[Dixie Slugs]

Very interesting and informative indeed! I have said for some time that there is a growing interest in shotgun bore cast bullets.
Now...before you get started on mold design, consider the following comments:
(1) what are you designing the mold for....smoothbore or rifled barrel use?
(2) What metal do you plan to use...based on the (1) question?
(3) based on (1) and (2) ....what game to plan to take.
Now, concerning (1)...there would be a different design for smoothbore and rifled barrels. Consisder that most rifled barrels will have a .727" in the grooves and 716" on the lands. There will be some variation based on who made to barrel, but the safe way is to use Hastings designed barrels. As with large centerfire handgun/rifle designs.....don't go over .003" larger that groove. And for sure if you use a heat treated design. For smoothbore barrel designs, a diameter between .727" and 730" are best in cylinder bore barrels This diameter and heat treated will give the best of all when it comes to penetration, without massive blood-shot meat. With any smoothbore barrels that has a choke...careful polishing in the choke area with a brake master cylinder hone on a variable speed drill at slow...is best. you want a firm slip push through!
As for the alloy...Wheelweight or a one in ten ratio of lead to tin is the best general alloy. For a harder heat treated slug...cook them at 400 to 450 degrees for one hour and quench in cool water.
In designing a mold for a smoothbore barrel...a hollow base at 1/3 of the overall length of the slug is fine...but this slugs skirts shold the thicker for support in the hard .250" nitro under the slug. Asmentioned...a truncated cone nose is beat, with a 75% meplat. In 12 bore, about .500" meplat is excellent. That slug should design out around 600 grs. and can be pushed, with select powders, to around 1500'/" for a 20" barrel.
With rifled barrels, design your slug to be solid and squared (length=diameter). Have a groove that is 1/3 of the side wall distance. That slug will design in about 730 grs, which the Brits felt was ideal.
Just some thoughts from Dixie

[longbow]

I'm with missionary5155 and round balls.

I have been having some fun with a 0.735" RB in both rifled and smoothbore. So far the smoothbore loads are as good as most smoothbore slugs I have shot at 50 yards (excepting Brenneke and AQ) and the rifled barrel loads, while not MOA, were much better than I expected given it was 1:38 twist and a 12 ga. RB wants about 1:120 twist. Easy to cast, easy to load and pretty good accuracy for first time out.

As for slugs, I really like the look of the Dixie Tusker and have a few to try. I will load those and some more RB's shortly for more shoulder bruising fun! Something like that with tumble lube grooves would likely be a good choice for rifled barrel ~ not that there is anything wrong with the Tusker as is.

Longbow

[catboat]

Very interesting and informative indeed! I have said for some time that there is a growing interest in shotgun bore cast bullets.
Now...before you get started on mold design, consider the following comments:
(1) what are you designing the mold for....smoothbore or rifled barrel use?
[B]Rifled[/B]

(2) What metal do you plan to use...based on the (1) question?
[B]Aluminum (that's what Lee Precision offers for a group buy)[/B]

(3) based on (1) and (2) ....what game to plan to take.
[B]Whitetail deer[/B]

Now, concerning (1)...there would be a different design for smoothbore and rifled barrels. Consisder that most rifled barrels will have a .727" in the grooves and 716" on the lands. There will be some variation based on who made to barrel, but the safe way is to use Hastings designed barrels. As with large centerfire handgun/rifle designs.....don't go over .003" larger that groove. And for sure if you use a heat treated design. For smoothbore barrel designs, a diameter between .727" and 730" are best in cylinder bore barrels
[B]So, are you stating a cast diameter of .728-.730 would work well in both rifled and smoothbore/unrifled cylinder choke barrels (naked lubed bullet, not paper patched)? What's the difference/point/need then between rifled and smooth bullet diameters?[/B]

This diameter and heat treated will give the best of all when it comes to penetration, without massive blood-shot meat. With any smoothbore barrels that has a choke...careful polishing in the choke area with a brake master cylinder hone on a variable speed drill at slow...is best. you want a firm slip push through!
As for the alloy...Wheelweight or a one in ten ratio of lead to tin is the best general alloy. For a harder heat treated slug...cook them at 400 to 450 degrees for one hour and quench in cool water.
[B]target alloy is wheelweights.[/B]

In designing a mold for a smoothbore barrel...a hollow base at 1/3 of the overall length of the slug is fine...but this slugs skirts shold the thicker for support in the hard .250" nitro under the slug. Asmentioned...a truncated cone nose is beat with a 75% meplat. In 12 bore, about .500" meplat is excellent. That slug should design out around 600 grs. and can be pushed, with select powders, to around 1500'/" for a 20" barrel.

With rifled barrels, design your slug to be solid and squared (length=diameter).
Why? Wouldn't a rifled barrel stabilize an elongated projectile?

Have a groove that is 1/3 of the side wall distance.
Why? Just for weight management/control (needed to "make realistic/target projectile weight), or is there a specific performance characteristic associated with it

That slug will design in about 730 grs, which the Brits felt was ideal.
Just some thoughts from Dixie

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Thank you for your comments. Looking forward to your further explanations.

[Dixie Slugs]

I don't know if I can answer the questions in the format they were asked.
Let's take the length of the projectile. You can check Greenhill to see if your designed slugs length will stabilize in your barrels twist. A good starting point is a squared solid bullet in 12 bore which will give you close to 730 grs. This design will stabilize in a one turn in 34" all the way to a one turn in 90" or so. The fast twist in todays barrels, say a one turn in 34", is designed to work with a slug/sabot out to somewhere around 2.00" in 12 bore. A squared slug will use the same rate of twist that an equal diameter round ball would use.
The 1/3 length groove has been used since Paradox days as a lube groove and to reduce sidewall friction...in both rifled and smoothbore designs...but by all means use what you think is best.
A hard cast 600 gr hollowbase slug/bullet can be used in both smoothbore and rifled barrels. the .727"/.730" diameter comes from the groove diameter of most of todays rifled barrels.... and yet fits tight enough in todays smoothbore cylinder barrels...or choke bores the have been polished to a slip fit.
From actual testing we have found that a hollowbase around 1/3 of the slugs length will give enough weight forward to keep the slug flying straight out of a smoothbore barrel. Many of the older foster designs had more
Bottom line is, these suggetions come from what we went through designing moden slug.bullets for Dixie.....you can make up anything you want!...James

.

[Dixie Slugs]

And....we do use a heavy Alox wash on all of our designs, including Tusker....James

[catboat]

Your comments are much appreciated. Thanks.



1.00 oz = 437 grains
1.50 oz = 656 grains
>>>>>>>>>>>>> 1.67 oz = 730 grains
1.75 oz = 765 grains
2.00 oz = 875 grains

[kycrawler]

i would be interested in a couple moulds if it were 500-650 gains .500 meplat tc style boolit 728-730 dia cast from wheel weights

looks like i may order some of the tuskers from dixie as they look pretty nice

[Dixie Slugs]

Since reloaders and casters seldom buy loaded ammo, to show that Dixie supports what you all are doing.......give me an email at jcgates@bellsouth.net and I will send you a machine drawing of Tusker.........or see the attached jpg.
This drawing is based on bullet alloy dropping at .728". I dom't think any other ammo maker will do that indeed! I hope this shows that we support Cast Boolits!
Regards, James

[scrapcan]

James,

You are correct in that not many others will openly share. And I am also very glad that you are willing to share. Thanks a bunch for sharing your knowledge. I am not a slug gun shooter but it is nice to know you are out there and willing to help the rest of us.

[johnly]

I've just started a similar project.

I ordered a 20 gauge rilfled Encore barrel and some brass cases. I'm planning on using an altered 20 ga slug mold or 58 caliber BP mold so that the bullets will have standard lubrication grooves and match the bore diameter of the barrel.

NEI offers a 20 bore rifle mold, as well as a 12 bore; I just wanted to be different.

John

[Dixie Slugs]

You want to check the diameter of the shotgun bore molds at NEI. We use NEI molds that have been cut for our custom bullets. We find that their regular shotgun bore molds run too large for todays rifled barrels....for example. Hastings barrels are .716" on the lands (bore) and .727" in the grooves. You do not want more that .003" compression in the grooves.
Regards. James

[longbow]

James:

That Tusker is one nice looking slug for sure.

I have to get out and try the few I have. I'll be using a smoothbore so I'd be curious as to what range they stay stable with nose forward - without the help of rifling.

Thanks for sharing James.

Longbow

[crowbeaner]

Ditto what Longbow said; a very good looking slug. What powders do you recommend for the Tusker? Wads? How much are you charging for precast ones? Roll crimped?

[Dixie Slugs]

Let's see if I can answer these questions. First of all, the Tusker is about the third generation of molds and tests. iI knew what I wanted. (1) a nose heavy slug for smoothbores, (2) a better design nose with a big meplat, (3) and....one that had appliction in both smoothbores and rifled barrels. (4) Plus, a big plus...was one the would stand up to stress involved in deep penetration and busting big bones! Tusker does all that!
Now, how far will the nose stay forward? Don't really know...stayed straight within what we consider smoothbore slug ranges. Gregg shot them at 50 yards and said they hit absolutely straight.
Wads....we tried a bunch indeed! We found that a slug must have a firm wad column! Our wad stack for Tusker is....50 grs of Primex 513 - X12X op - .250" hard nitro - 3/8" hard filler - .250" hard nitro - Tusker - and rolled crimp. Leave plenty of room for the rolled crimp to reach down on the slope of that truncated cone nose.
No....we are not selling any Tuskers as a component. That's why I posted the machine drawing. By the time they are hand cast, heat treated, and lubed... and made from certified bullet alloy....they would be costly indeed.
Primex 513 is not available to the general public, but 46 grains of Blue Dot would be a good starting point...but I doubt you will be able to get to 1500''/" with Blue Dot. We did sme work with Longshot, but found it to be tricky on the top end of pressure.
Tusker is 1 3/8 oz and we tested another brand that was supposed to get to 1500+'/" with that weght.....it clocked only 1275'/" from our 20" test barrels. I suppose they published the velocity from a 30" pressure barrel?????
I will say this...Tusker at 1500'/" is not for guns under 7/8 pounds! One big shot visiting the Linebaugh Seminar found that out when he busted his eyebrow with a scope ring.
If the truth be know....Tusker loaded anywhere between 1300'/" and 1500'/" will knock over about anything indeed!
Regards, James

[Johnch]

Thanks for the drawing !!


I have been working on a slug mould , based on a wild Idea I dreamed up
A nose pour solid base , with a small drilled through hole
That I am going to TRY and attach a wad to , something along the line of a Brenakee
But I am just going to use a machine screw and nut through the whole wadd colum and slug

Figured a .6 meplate didn't need to expand

First time I cut the mould it droped to small of slugs

Had been working to much , to get into the shop and bore out the mould

John