New slug design

[Cap'n Morgan]

Here we go again...

This time I will try to combine a sabot slug with a Brenneke helical profile to get a slug that is as simple as possible - yet reasonable accurate. I have had nothing but positive experiences with my Brenneke clone with injection molded wads. By adding the helical ribs to the wad instead of the slug, the casting of the slug will be faster and more simple as it can be done in a "normal" mold. Also, the slug has a spigot instead of an internal cavity and should hold up better when hunting dinosaurs.

The two parts are meant to be pressed together with considerable force - no glue or screw. The reason for the square spigot/hole is just in case I later would want to make a plain wad without ribs for rifled barrels - then the square shape will keep the slug from rotating in the wad.

The combined wad/slug is rather short and lack any form of sealing and crushing in the wad. I have yet to find anything better than the x12x seal for foundation when stacking a slug load so this what I'll use here.
Notice the rather pointed nose on the slug. While it no doubt results in a better ballistic profile, I hope it will improve the airflow over the front of the ribs and help to induce some extra spin in the slug. The pointed shape should also move the drag a bit further down the slug to improve stability (my previous sleeve-slug design became extremely unstable when crossed with a pure flat-nose slug)

https://i.imgur.com/6xq6HvG.jpg

https://i.imgur.com/TsEQQtM.jpg

This is what the wads look like so far. Next step will be to make the mold for the slug.

https://i.imgur.com/exJ7BEy.jpg

[Hogtamer]

You and Uncle Dino are brothers by different mothers!

[uncle dino]

Man those look great.. Wish you were closer. D

[KrakenFan69]

That is wicked! I'm definately interested in how this progresses!

Kraken Fan #69

[Oklahoma Rebel]

very cool, even if it doesn't spin, which it looks like it should, the rib around the exterior base of the wad will provide some rear end drag to help keep it pointed in the right direction. the point is smart, with a blunt profile, the fins will be in a low pressure "wake", which would either reduce or ruin the efficiency of the angled fins

[longbow]

I'm liking the looks of that Cap'n Morgan!

I gotta ask though... why a square shank on that lead nose cone? A press fit with cylindrical shank would be easier to make (I think anyway) and should provide plenty of hold in the plastic tail wad. Just curious... and I know you must have a reason.

You might have to beef up the ribs but recovered slugs will tell you if you do. The AQ slugs I shot had quite "beefy" ribs and they tended to flatten out quite a bit. Not sure what the plastic or hardness was on those though and they didn't have a lead shank down inside either so that may take some of the compression away from the tail wad.

Good stuff and as always terrific work!

Longbow

[Markopolo]

Wow... very very cool.. you are really having a blast with the injected wad stuff... I imagine now that you are all tooled up with the injection stuff, your imagination is your only limit... very very cool.. I imagine hogtamer and longbow are drooling all over themselves!!!

I imagine the square shank will totally prevent the slug from rotating independently of the wad... great idea!!!

[Blood Trail]

If I’d only had half the skill you and Uncle D have. I’m excited to see the finished product!


Sent from my iPhone using Tapatalk

[Cap'n Morgan]

Guys, thanks for your positive feedback. Time will tell if the project has any merit, but it's always fun to tinker with new ideas.

As Longbow pointed out, I may have to enlarge the ribs and maybe the overall diameter as well as the wads have shrunk a tad more than expected, but it's easy to enlarge a mold - not so much the other way around!

To be continued...

[CraigOK]

very cool, keep us updated

[Rally]

Great idea, especially the square shaft. The only thing I would question is the leading edge of that wad catching or folding as it leaves the casing, especially with a roll crimp. If the leading edge of the wad was flush and just the ribs extended outside the slug it would probably open the crimp better, with less chance of rolling the leading edge of the wad backwards. If the slug itself was as large in diameter as the wad, the slug shoulder would open the crimp and make it easier for the wad to pass out of the casing/hull.

[Cap'n Morgan]

Rally.

The reason for the slug being smaller than the wad, is, that the combined slug must be able to pass through a full choke without damaging the choke. My Brenneke clone utilize a full diameter slug, but here the slug has ribs (and a hollow base) to allow the slug to be fired through a choked barrel.

[Rally]

Capn Morgan,
I admire the concept and design, but at launch, the wad will compress to some extent first, before the actual slug starts moving. I'm picturing the leading edge of that wad rolling outward, to the extent the hull/ chamber will allow, upon compression, as the actual slug starts moving. The edge of the crimp is going to be in the near vicinity, and I'm guessing, going to cause some deformation of the leading edge of that wad. If the deformation is uniform, it may not hurt a thing, but like electricity, plastic tends to take the path of least resistance under pressure. If I were as capable as you obviously are, at forming this wad, where the leading edge is now, I'd add a band equal to, or even twice as thick as the ribs on the sides are. My reasoning being that there is going to be some gas leakage, and the ribs are going to help divert that gas to the top leading edge of the wad. With the rib all away around the top edge, upon launch, it would compress to hull/chamber/bore diameter and form a second forward gas seal, and also help during constriction at the forcing cone, trip down the bore, and at choke constriction( if any). I'm guessing it would also help with stabilizing the base of the slug during launch. The forward rib would likely be the first thing to come in contact with the outward edge of the crimp also.

[Cap'n Morgan]

Today I got around to make a mold for the new slug:

https://i.imgur.com/XAP56Ui.jpg

Hope to cast some slugs next week.

[jmort]

You have mad skills
I have long felt the AQ design, your design is the answer. The plastic ribbed tail was larger than the business end which made sense to me. .678” v 660” ??? May have been full Bore, .730” v .690”
I am impressed by your efforts as they are way above my skill set.
I see you addressed this in post # 12

[Outer Rondacker]

Send some of those over my way I will give them a proper testing. :}

They look great. Keep up the good work.

[longbow]

Yes! Drooling all over myself sums it up!

This is impressive stuff to say the least!

Cap'n Morgan is definitely on the cutting edge.

I'll be eagerly waiting (and drooling) waiting for range reports.

Longbow

[Blood Trail]

Tagged for greatness


Sent from my iPhone using Tapatalk

[Cap'n Morgan]

Cast a few slugs today. The concept works exactly as hoped. The wad/slug fit are so tight I can't imagine them ever separating in flight. The combined weight is slightly over an ounce (450 grains), which was what I aimed for, as I would like to try a lighter (and faster) slug with the Red Dot equivalent powder I normally use.

All that remain is to load up a handful of shells and off to the range... Unfortunately, the weather is freezing cold with high winds, BRRRRrrr...... so actual testing may have to wait awhile.

https://i.imgur.com/fYpHbNZ.jpg

[W.R.Buchanan]

Didn't know you are a machinist. Nicely done Sir!

Randy

[Outer Rondacker]

Looking good. A drop of glue on the lead before putting it in the wad might help keep it in place. Dollar store crazyglue perhaps.

[BigMrTong]

Brilliant! Right up my street. Would love to test some in the future 👍🏻


Cast a few slugs today. The concept works exactly as hoped. The wad/slug fit are so tight I can't imagine them ever separating in flight. The combined weight is slightly over an ounce (450 grains), which was what I aimed for, as I would like to try a lighter (and faster) slug with the Red Dot equivalent powder I normally use.

All that remain is to load up a handful of shells and off to the range... Unfortunately, the weather is freezing cold with high winds, BRRRRrrr...... so actual testing may have to wait awhile.

https://i.imgur.com/fYpHbNZ.jpg

[Hogtamer]

No they won't come off! There's going to be some setback at ignitionthat will tend to splay the wad a bit I would think. That will be interesting to see and a mild load may be just the ticket.

[W.R.Buchanan]

I'd bet these would do good at 1100fps and literally knock the snot out of what ever they hit

That is the speed of my Round Ball Loads and snot flies when they hit.

This is one of the best slug solutions I have seen, and if the stabilize like I think they should I'd call it a winner.

Randy

[Cap'n Morgan]

I put together a few rounds yesterday. 18.5 grains of Vectan AS (Red Dot) topped with a x12x seal and a 3/8" fiber wad in a 2 1/2" RIO hull (trimmed down from 2 3/4") - then off to the range! The weather was downright awful and I only brought along four rounds just to see if I was on the right track. The range was 50 yards (52 to be exact) and the gun was my trusty Browning A1 with a Leupold X2 handgun scope. I quickly rattled of all four shot and went to examine the target:

https://i.imgur.com/vQuOeBX.jpg

The result was not bad at all. All for shots were well within 4" and the three of them was an even inch! I wish I could say I jerked one of the shots, but all four felt OK when I took them (did I mention the weather was awful?). Still, the slug has clearly potential and further testing is on my schedule. The wad could do with a little larger diameter at the bottom. Right now it's 0.72 while the front diameter is 0.728 (the Brownings's barrels are both 0.724). I didn't try to recover any of the slugs as the berm was frozen and (you guessed it) the weather was awful.

[SuperBlazingSabots]

Greetings Cap'n Morgan, that looks very good.
Wish you the very best.

Best regards,
Ajay Madan
Super Blazing Sabots

[longbow]

Looks like you've done it again Cap'n! You are a tough act to follow.

I do like the basic design of this slug. It is similar to the old AQ slug in a lot of ways and that was one I tried to copy in my simple way. While I did have some success, your approach is far more refined so I suspect you will kick AQ's butt!

I am on board with your comments about HB slugs and trying to get enough wight forward design without too fragile a skirt. Attached wad is the way to go... in my opinion anyway and you have it nailed!

There are several benefits to your design in that it could be made considerably oversize to suit almost any reasonable bore size but it should swage to fit easily, it is choke friendly which is one of my criteria for preferred slug designs, it allows for extreme weight forward design and also can use hard or soft lead and those spiral ribs should impart some spin which should minimize "wander" from any imperfections which in the case of your should be very small anyway.

Yes, I know I used to say that rifled slugs didn't spin but I was more referring to not spinning enough for gyroscopic stabilization. However, it is now proven in slo-mo that even rifled Foster slugs do get a small amount of spin and that should help keep them from wandering too far off course. I stand corrected! The ribs on your slugs should be even more effective.

As always, you've done excellent work and have the results to go with it!

Longbow

[jeremy360]

I just bought a Charles Daly over under. Remington chokes, picatinny scope mount. I have planned on setting up one barrel for slugs (so far thinking the lyman 525), the other for tight 7 1/2 bird shot with a turkey choke. Been doing lots of research and following these posts. I'd love to see if someone could capture this in slow motion to see what happens in flight.

Almost wonder of something like the old gyrojet could be accomplished by letting a little of the combustion gas through angled ports in the wad (or bullet i guess). heck, even if powder was packed in a small angled port like the gyrojet. I would think the best stabilization out of the barrel would be if the bullet was spinning inside the barrel before it exited. I've also thought about if there was a way the combustion gases could spin the slug just as it exits the barrel...or through a ported choke.

I also wondered if the channels had the small hole at the front and the big hole of the channel at the powder end could make it swell to the bore diameter. A fellow I once knew used to put tiny holes in his pistons from the head of the piston to behind where the rings are seated to allow the pressure to press the rings against the cylinder wall harder to achieve a higher compression ratio.

That being said, this is a more eloquent solution. Hats off to everyone that has been devoting their time, money, and shoulder to this research. I've always been a fan of tinkering, but you guys are taking this to the next level.

Congrats on the success y'all have achieved.

-Jeremy

[Hogtamer]

That needs patent protection. Somebody's gonna steal that Cap'n. If I had the skill I'd duplicate it for personal use. I know shotgun slugs are a small $ proposition for manufacturers, bit one would think somebody like Lee would market molds and sell wads like that and make a little money....after paying you a development fee or buy the rights from you. Definitely a better mouse trap.

[RogerDat]

Just started looking into doing slug casting and loads and your design looks like it hits all the areas of concern over deficiencies or shortcomings in other designs. You should totally go for a patent. Maybe offer the mold as a group buy, how to get those wads I don't know but if you could interest a manufacturer I'm sure they would command a premium price. Might even be able to fund a limited run off of group buy commitments.

Looking forward to seeing this project progress. Good luck getting a patent and hopefully a commercial supplier interested in your design. Impressive!

[Cap'n Morgan]

The thought of getting a patent on the "snap-slug" did cross my mind, but then again; ideas should be shared, not necessary patented. If someone would like to copy the idea or perhaps contact Lee for a feeler, by all means go ahead. I only request the name of the slug must be "Cap'n Morgan";)

I thought of a group buy as well. I wouldn't mind making the molds, but to make wads in the thousands, a "production" injection mold is needed, and it could be a problem to guarantee a constant delivering in the years to come.

Anyway, the project is still on. A friend of mine has a Mossberg with a rifled barrel and we'll try the new design and see what happens. If successful, I might add an extra cavity to the injection mold for a smooth sided wad for rifled barrels only.

[Cap'n Morgan]

Almost wonder of something like the old gyrojet could be accomplished by letting a little of the combustion gas through angled ports in the wad (or bullet i guess). heck, even if powder was packed in a small angled port like the gyrojet. I would think the best stabilization out of the barrel would be if the bullet was spinning inside the barrel before it exited. I've also thought about if there was a way the combustion gases could spin the slug just as it exits the barrel...or through a ported choke.

-Jeremy

I had some similar thoughts - like a hollow steel-slug with angled nozzles. The hollow chamber in the slug would be pressurized equal to the chamber pressure from the powder charge before the slug had started to move - and the pressure would then bleed off during the travel down the barrel while at the same time spinning the slug. As a benefit, the "two-stage launch" would increase speed without increasing pressure. A bit like the German WWII 8 cm PAW 600 - only in "reverse"

https://en.wikipedia.org/wiki/8_cm_PAW_600

I never followed up on the idea. After all; we're talking slugs here - not rocket science ;-)

[Cap'n Morgan]

Did another test today - this time at 100 yards - fired only three shots and went to look at the target. One words comes to mind... disaster! The three shots barely stayed within the 2'x2' target, and the shape of the holes clearly indicated that the slugs had tumbled. Shaken (but not stirred) I moved the target to 50 yards and shot three more rounds. This time the group was less than 4" and the holes were round! This had me scratching my head - obviously bad things happens to this slug after the fifty yards mark.

I went home and did a bit of googling and happened upon the book "Fluid-dynamic Drag". It seems that for subsonic velocities a semi-sphere has the least pressure drag of all shapes:

https://i.imgur.com/IGmlABm.jpg

I'm going to make a couple of new molds, one with a semi-sphere nose profile and one similar to the Brenneke design and see if things improve. Good thing I made a bunch of mold blanks last time.

[KrakenFan69]

**** Cap'n, you are on some next level **** here! Great work and keep refining that bad boy! Very cool to follow your progress.


Kraken Fan #69

[longbow]

Cap'n:

Something that has stuck with me is a comment made by turbo1889 that the Lyman Sabot slug becomes unstable at transonic velocities (when launched at supersonic velocity) and starts to tumble when shot from smoothbore.

I wonder if the change of location of the shockwave on your slug as it goes transonic might be causing some grief!

I am not sure turbo's comment is 100% accurate but it does reflect wadcutter behavior from handguns... accurate for a distance but unstable at long range. Mind you those are usually launched subsonic too...

Assuming you are launching your slugs at supersonic velocity now maybe you should try them subsonic before modifying. If they remain stable that will tell you something. And/or put large pieces of paper out at say 50m, 70m, 90m, and 100m so the slug's patch with be through all then see where it loses stability. That will tell you something too and if you can work out a ballistic coefficient that may tell you about where the slug goes transonic.

Turbo also commented on ideal length to diameter ratios as well. Slugs are not arrows so longer is not necessarily better. Nose heavy and appropriate drag stabilization is what matters. It seems to me he said for attached wad slugs the length to diameter ratio should be about 2:1 max. I'd have to dig through my old downloads to find it though.

I always look at Brenneke Classic slug length to wad length comparison. old Wilhelm Brenneke got it pretty much right on!

All in all you are still on the cutting edge here and I am sure you will win in the end.

Longbow

[Cap'n Morgan]

Longbow -
You could have a point there, I didn't crono the loads, but a similar load - with the sleeve-slug - was around 1100 fps. Compared to my Brenneke clone which have a 1.75:1 length/width ratio, the new design is about 1.5:1 - and less nose-heavy. Two things that could cause instability.

Come better weather I'll try different speeds at different distances. If a slow load (about 900 fps) remains stable at 100 yards, then the transonic zone is the culprit. Time will tell.

[jeremy360]

Not sure if this helps, but take a look at shock wave location as a function relative to the speed of sound. Obviously it will change based on the shape of the bullet, but still gives a general idea.

216703

[longbow]

I wondered why Lyman came up with the diabolo slug design but it follows diabolo pellet design and at supersonic velocities the shock wave should move to the tail. This may be why turbo said they lose stability at transonic velocities when shot from smoothbores (I don't know that that is entirely true)... but I don't know that it isn't either.

Some people report quite good accuracy from smoothbores out to 100 yards. I have not tried that design yet. I am wishing I had gotten in on the Mihec 2 cavity Lyman sabot slug clone group buy. If nothing else, I'd have another excellent Mihec mould!

Longbow

[jeremy360]

Well....i just got my Lyman 525 gr mold in yesterday. It'll be fired out of a 24" barrel with the 5x scope mounted directly to the barrel (break open over under). I also bought a Carlson' s rifled choke against the odds. I will try the slug with reg choke, then with rifled choke, then with a little knurling and the rifled choke to make sure it's not the wad spinning and the slug doesnt. Maybe I can be another data point....

[longbow]

I know I'll be interested in your rifled choke results. I still lean towards smoothbore due to unequaled versatility but I would like better long range slug accuracy. It seems like an appropriate rifled choke tube is the way to go.

I say "appropriate" because I think that modern rifled choke tubes have too fast a twist and too shallow rifling. Having said that, if I had a gun tapped for choke tubes I would have bought a rifled choke tube by now and tried it out. So again... I'll be interested in your results.

I've probably mentioned it in this thread somewhere but I have been planning (for a long, long time... but I'm slow) to make a deep groove slow twist rifled choke tube. The rifling machine is build and works. Now to get the bits together to add choke tube ability to my gun. I don't believe anyone locally reams and taps for choke tubes so I am looking at the Colonial Arms choke adapter.

You will undoubtedly be shooting slugs through your choke tube before I am done so I am absolutely interested in how it does for you. Even if the Lyman Sabot slug slips in the wad, a full bore slug should grip. I have a home made mould that casts a nice 565 gr. smooth slug at 0.729". I could send you some.

Longbow

[jeremy360]

Thanks Longbow, ended up putting a 3-12x scope. I need to measure the bore to see what im working with.

[Sitzme]

Did another test today - this time at 100 yards - fired only three shots and went to look at the target. One words comes to mind... disaster! The three shots barely stayed within the 2'x2' target, and the shape of the holes clearly indicated that the slugs had tumbled. Shaken (but not stirred) I moved the target to 50 yards and shot three more rounds. This time the group was less than 4" and the holes were round! This had me scratching my head - obviously bad things happens to this slug after the fifty yards mark.


You could send some samples to Taufledermaus for testing using high speed video. He has a Youtube channel and tries all kinds of things in 12ga. The videos really show a lot of detail.

[Cap'n Morgan]

Finally got around to modify the original mold to a semi-sphere design. The modification brought the combined weight of wad and slug up to 490 grains - a bit heavier than my original plan, but I can always make a new and shorter mold. As a bonus, the center of mass has shifted forward a little which should be a good thing.

Next step will be to load up a handful of subsonic loads to test at 100 yards and see if the slugs still tumbles after the fifty yards mark. If it doesn't, I'll try with a supersonic load to see if anything changes and if a slug-tumbling gremlin really lives in the transonic area.

https://i.imgur.com/VzmmwX3.jpg

[jeremy360]

Those look great. Interested for the results!

[KrakenFan69]

Man I wish I lived near you! Very cool.


Kraken Fan #69

[Hogtamer]

Great work, good test plan. The nose heavy feature will power it through destablization forces I believe.

[longbow]

Cap'n:

Those are looking a lot like the old AQ'S! Big difference is AQ's had a hole in them that the wad inserted into where you have the lead tit sticking out to go into the wad.

How does that leading edge of the wad hold up? I had thought it looked a little fragile and might flare out after being squished between bore and slug nose.

Those slugs do look good though. I'm with Kracken... I wish we were closer so I could pilfer your slug stock and do some field testing.

That design looks like a good one for zinc slugs too. I suspect that in not too many years lead will be on the endangered list for boolit material. A guy has to look ahead!

As always, terrific work and pics!

Longbow

[Cap'n Morgan]

Longbow.

I haven't got around to examine any of the slugs after impact but I plan to do so. We have a small shooting range a few miles from here where I sometimes run impact test. The range is situated in an old gravel pit which holds some extremely fine-grained sand which does very little damage to the slugs. A large snowdrift would be better, I know, but most winters we're low on snow - which is a darn shame as my favorite hunting objects are foxes in the wintertime.

It shall be interesting to see if the tumbling is somehow related to the transonic area and if the new design will improve things. Should it happen that the slug will behave at subsonic speeds but cannot cope with the transition I'll probably change the mold to as heavy a load as I can safely get away with. Might as well pack some punch...

[longbow]

Many years back when I tested some Dixie Tuskers I got mediocre to poor accuracy from them from my smoothbore (while HB they are designed for rifled guns). Holes were round in the paper at 60 yards so not showing signs of wobbling but I decided to try them to 100 yards to see if they still flew straight so lined up target frames at 60 yards, 60 yards, 75 yards and 100 yards with about 3' x 4' paper and set a target hig hon the 50 yards paper then shot. While groups were large all holes were perfectly round through all the papers.

The Tuskers I had were sized to 0.727" and hard cast (like cast iron! Hard!) and shot from a 0.733" bore so rattly. I figured they were nose heavy enough to be stable but were leaving the muzzle at slightly different angles each time. Regardless once in the air they seemed to fly well. I may have mentioned I like the Tusker design!

There I go rambling on again! Point being that you might try the same thing and line up 3 or 4 target frames with big paper then shoot and check holes at each range. If the slugs lose stability past 50 yards you'll know in very few shots.

We have very fine sand here too and lots of it! I was shooting into it last Sunday and recovered several slugs. I'll be writing that range day up shortly.

I've got faith in you Cap'n! You'll beat this instability thing.

Longbow

[Cap'n Morgan]

Did a test yesterday to see if the new slug profile would be stable at subsonic speed. I didn't use a chrono, but the estimated speed was about 1000 fps or less. The range was 90 yards and I just fired 3 rounds to check if the slugs still was flying nose-on at that range. Well, let me tell you; They didn't! All three shots hit the target sideways as per the picture.

The three shot marked with a triangle was the result of my previous test at 100 yards. At that time I was a little puzzled that all three imprints was sideways in the target, but thought it was just a coincident. This time around the three shots (marked with a circle) showed the exact same behavior. This can't be a coincident. I wonder if the slugs are not tumbling, but actually fluttering the "tail" from side to side like a car out of control on a slippery road. This could explain the sideways impact as the slug is only flying nose-on for a very short time between the jerks. Notice that the group is a respectable 6" - not bad at 90 yards, but the ballistic must be horrible.

I'm afraid this slug is too short and the center of mass should be further forward. There's still a couple of things I will try, but chances are this slug will not fly properly beyond 50-60 yards.

https://i.imgur.com/oN0yQgN.jpg

[Hogtamer]

Perhaps the result would be better with a much faster load, say 1500 fps.

[longbow]

Maybe you should try the AQ approach and put a hole into your lead nose cone then put a tit on the wad to press into the hole. That would move the CG forward about as far as it can go. You can always lengthen the nose cone a bit to get to same weight as now. The AQ's I had were very nose heavy and basically balanced... just a nudge and they would stand on their noses.

Did you recover any slugs to examine the plastic tail wad? I still wonder if that thin front lip might be opening up a bit after being squeezed between bore and nose cone. That could make the slug unstable if it is opening up at all.

My solid "Brenneke/AQ" like slugs are flat bottomed then I put a #10 wood screw in a cast-in starter hole and cast the hot melt glue skirt onto the base. That holds amazingly well. Yours would be classier than that by far so should work well. I was actually trying to copy AQ's as best I could with what I have and they work well if the skirt is well cast.

As for the wobble you mention, I agree that is likely what's happening... a rapid/violent flipping from side to side. There's some slo mo video I've seen (likely Taofledermaus) with slugs showing that sort of tail oscillation.

Like I have said... I think there is black magic involved with getting good and consistent performance from smoothbore slugs!

Longbow

[Cap'n Morgan]

I think I'll try HT's suggestion and try raising the speed - probably make a new mold as well; 1500 fps with a 500 grains slug is not my cup of tea.

Longbows suggestion will be next in line. It will be a little more complicated than my first design, but it will be much better wrt the balance in the slug. It's back to the drawing board once more <sigh>

[longbow]

Not sure if you are familiar with the AQ's but I believe they are of European origin though BPI marketed them here like they were a BPI product.invention.

Here's a link with pics:

http://www.guns.com/2017/06/02/slugging-it-out-the-quest-for-the-perfect-self-defense-shotgun-slug-load/

The ones I tried shot very well from my Browning BPS slug barrel. If they hadn't been so expensive to buy I'd have bought a truckload of them. The only real downside is that they were soft lead. A wad slug version with hard cast would be great and is what I tried with my hot melt glue skirts with some success. With your injection moulded wads you would be able to reproduce these or similar maybe as a short fat conical weighing 500 to 600 grs.

What I liked was that they were so nose heavy they just rocked up on the nose with the slightest nudge.

I know you'll get this beat however you approach it Cap'n!

I am a bit familiar with that "back to the drawing board" thing...

Longbow

[megasupermagnum]

It always makes me wonder how Brenneke got it perfect so long ago. To me, just laser eye-balling that stem, it has quite a bit of meat to it. I think those are just too tail heavy. I like that you went with a cast stem slug, rather than a hollow base, but I think you will need a longer plastic tail. For a test, I've thought about trying to glue some felt wads on slugs. I've never tried it, but it might be just the trick here.

[longbow]

I think glue will fail or the wad will fail at the glue line. It's worth a try but those wads take a beating at 10,000 PSI! I tried screwing nitro card wads on as tail wads and they delaminated and were all scraggly when recovered. Some of the scraggly was due to impact but not all of it I am sure. Accuracy was poor.

The screw through the butt has worked well for Brenneke, Vitt Boos and some others for a long time.

In fact, next order I put in will include some felt wads from BPI to try something similar to the Brenneke with screwed on felt tail wads. It is something I have not tried but should have long ago. I went to the cast on glue wads which work but are a bit tedious to do. I think making up a punch to put a screw hole in the center of a felt wad would be pretty easy and fast to do. My slugs have a cast in screw starter hole so not problem there. If it works, great! If not I've got some felt wads for spacing/cushion.

It is amazing that there never seems to be an end to what can be tried at this game! I've slung hundreds of pounds of slugs downrange over the years and am still looking for the elusive 100 yard "nice" group. Done it with factory slug loads and factory made slugs handloaded but not home made slugs... yet! Consistency is the name of the game I think, that and solid wad column.

Give it a go and see what you get. It's all good stuff and fun trying things. We keep learning.

Longbow

[megasupermagnum]

I've been buying a lot more from Precision Reloading recently, and I've found their felt wads to be better. BPI 1/8" thick are OK, but their 1/4" versions look like two 1/8" stuck together. The PR ones are perfect by comparison. I also find the fiber wads from PR are less stiff, yet hold together much better than BPI. I think a dab of silicone with a 1/4" felt wad would stand a good chance. I've had card wads glue themselves to slugs accidentally with nothing but a tiny dot of bullet lube. It would at least show if a longer tail would help.

[longbow]

I may have to try Precision Reloading for those then. Not sure if they'll ship to Canada though. BPI used to but there is a Canadian BPI rep in Alberta who is good to deal with so no cross border problem there. It depends on the dealer and product whether they will ship to Canada. Makes it tough in rural areas where there are no large guns shops and reloading supplies.

I'd still think that the felt should be trapped between a couple of leather or tough plastic washers like Brenneke does. If the trailing edge of the felt gets ragged it will affect accuracy. I've long maintained that consistent dependable wad column and in the case of attached wad slugs, consistent attached wad are essential to consistent accuracy. It doesn't take much to cause inaccuracy.

The old Brenneke classic slugs looked to me like they were assembled then a punch run over the assembled slug to shear the wad to final size. However they did it the slugs were extremely consistent. Nowadays with injection moulded plastic tail wads can be virtually identical. It is tough for the basement tinkerer to match that.

Longbow

[Cap'n Morgan]

Well, I'm finally getting ready for round three with my latest slug design.

The previous design, while accurate and stable up to about fifty yards, it would hit the target sideways at longer ranges. I decided to go with Hogtamers suggestion of a faster load - preferable around 1500 fps to keep the slug supersonic for as long as possible.

To accomplish this the slug had to be lighter - alas, a new mold had to be made. The new slug is much lighter - combined weight of slug & wad is 375 grains or 24 grams - same weight as the 1500 fps target loads we use over here.

https://i.imgur.com/ltaLhqZ.jpg

I hope the new profile and increased speed will create a true drag on the rear of the slug and keep it pointed nose forward.
The old subsonic design would start wobbling profusely after fifty to sixty yards - perhaps caused by the pressure wave building up in front of the slug.

Now it only remains to work up a chronographed load and test for accuracy and stability.

[jeremy360]

That's awesome...unforunately my 525 Lyman still is covered I in factory oil.

Those look good for sure...good luck!

[longbow]

Good to see you back at it again Cap'n!

Looking forward to range reports.

[BigMrTong]

Same, excited to see the results on these new ones

[centershot]

Well, I'm finally getting ready for round three with my latest slug design.

The previous design, while accurate and stable up to about fifty yards, it would hit the target sideways at longer ranges. I decided to go with Hogtamers suggestion of a faster load - preferable around 1500 fps to keep the slug supersonic for as long as possible.

To accomplish this the slug had to be lighter - alas, a new mold had to be made. The new slug is much lighter - combined weight of slug & wad is 375 grains or 24 grams - same weight as the 1500 fps target loads we use over here.

https://i.imgur.com/ltaLhqZ.jpg

I hope the new profile and increased speed will create a true drag on the rear of the slug and keep it pointed nose forward.
The old subsonic design would start wobbling profusely after fifty to sixty yards - perhaps caused by the pressure wave building up in front of the slug.

Now it only remains to work up a chronographed load and test for accuracy and stability.

This is confusing to me. Brenneke Classic 12 ga. slugs are 1-1/8 oz. (490 gr.), muzzle velocity of 1500 fps and fly accurately to 100 yards or more even though they become sub-sonic somewhere between 50 and 75 yards, according to factory data. This slug/tailwad is a close approximation of Brenneke's design, albeit with some differences; Wouldn't it make sense to increase the slug weight and load to higher pressure? 1500 fps should be attainable even to us handloaders, yes? Or, no?

[Cap'n Morgan]

Centershot

While 1500 fps is certainly possible with a 1-1/8 ounce slug, I'm too much of a chicken to go down that road. The new design may look a bit like an original Brenneke, but it's only the helical ribs that remains from that design. As long as the slug is not properly stabilized those ribs will not work as intended and the whole project will be somewhat moot. But until the slug is tested and fails I'm suffering from incurable optimism ;)

[Cap'n Morgan]

At long last I got around to re-test my latest slug design.

As you may - or probably may not - remember, I had high hope in this finned wad/solid slug combo. Unfortunately, the design proved to be quite unstable, with almost every single shot hitting the target sideways instead on nose-on. Hogtamer mentioned, that since a slow subsonic speed didn't work, maybe more speed would improve things. I had nothing to lose and made a new, lighter slug - upped the speed to 1450 fps and gave it a shot, so to speak...

The range was 50 meters. I fired five rounds, one on them either missed the target or went through a previous hole. The four holes measure a little over 4", and all four slugs has hit the target sideways! Clearly, although the slug has the center of gravity well forward, the overall length is too short to stabilize it flight.

I'm throwing in the towel here. Next design (and last, I promise) will be a swaged Brenneke slug of proven design.


The pictures speak for themselves:

https://i.imgur.com/BWac8bw.jpg?1

Notice how nicely the slugs fit the holes:grin:

https://i.imgur.com/4MYxtQx.jpg?1

[bikerbeans]

Capt.,

That lower hole looks like two impacts to me. Maybe one of your slugs hit nose on? Good luck with the Brenneke clone.

BB

[W.R.Buchanan]

Capt: I went back and read this entire tread. I see some issues that might help.

What you are trying to do is essentially an "AQ/Brenneke style slug." I just happened to have a new one on my desk in front of me so I took some pics.

The center of gravity on the AQ slug is WAAAAY forward. The entire slug is 1 1/8" long and the CG is less than 1/4" from the Front! It is approximately at the juncture of the nose radius and strait portion of the slug. The tail wad, or more properly fins are flared to insure bite and the tail plugs into the slug the exact opposite of what you did. That slug is so weight forward that with the slightest nudge it will roll right up on it's nose and stay there.

I just happen to have a Brenneke slug on my desk as well. I unscrewed the wad and the base is hollow except for the post that is threaded so the screw can hold the wad onto the slug.This is similar to Longbow's modified Lee Slugs,,, once again CG well forward.

The other type of Brenneke slug has a plastic wad that is plugged into the hollow base of the slug and is shoved into that base farther as it collapses at the moment of firing.

Even my Lee Slugs will roll up onto their nose with little assistance. The Russian Slugs are similar in that they also have hollow bases.

The Lightfield slug is supposed to be the most accurate shotgun slug there is. Hollow Base, weight way forward.

All these slugs have one thing in common. They all have deep hollow bases and their CG's are all at 1/4 to 1/3 of the total length, off the nose.

My STI Slugs with the brass inserts are 1 7/8" long and balance at slightly less than 1/2" off the nose. (They are for rifled barrels but the same holds true for them.)

I think the problem you have is that your CG is not far enough forward.

I think if you reverse the design so that the wad plugs into the nose, as opposed to the nose plugging into the wad, you'd have it beat.

On another note,,, Your mould work is excellent!

Randy

[longbow]

turbo1889 had some balance point guidelines and length to diameter relationships he claimed were correct and that a slug over 1 1/2 or maybe 2 times diameter would be unstable. Now, I think he was talking Foster lead slugs not attached wad slugs but that always stuck with me and is the reason I have questioned form versus CG. The AQ is certainly long and very nose heavy but apparently like a rifled slug there is some spin imparted by the spiral vanes so maybe that plays a part. turbo maintained that the Lyman sabot slug was unstable at transonic velocity and would start to tumble (from smoothbore)... yet, I see Taofledermaus video of the Moose .69 Minie and Lyman 730 gr. .69 Minie flying perfectly stable from smoothbore. Both have pointy noses where the weight is and large bodies where the weight isn't. I'd think if they tipped there is noticeably more drag on the tail than the nose.

So, point being that maybe a somewhat more streamlined/pointy slug might be better?

Of course I am guessing and somewhat grasping at straws having tried many things but mostly being marginally successful of failing. My Moose Minie copy yet to be tested (after the archery shoot!).

Maybe a Moose Minie copy with attached wad would be something to try?

Longbow

[Cap'n Morgan]

Randy, one of the reasons I chose the "hollow wad" design instead of "hollow slug" was to have a slug that was easy to cast without a core pin in the mold. Also, the "stem" on the slug should support the wad against compression during launch. I may take another look at the wad injection mold to see if it can be modified without too much work involved.

LB, I have contemplated a more streamlined/pointed design myself. But apparently a hemisphere is the best ballistic profile as long as the speed is in the subsonic area. Federal's Foster slug is still supersonic out to 100 yards, but they start out at a brisk 1520 fps with a 1-1/8 ounce load and I'm a little reluctant to go the highspeed way (besides, I'm running low on Blue Dot with little chance to find more)

[W.R.Buchanan]

I used to think that a drag stabilized slug would be accurate. Then my mind drifted back to my Airplane Mechanicing days.

I remembered that tail surfaces on certain planes, got "blanketed" by the Airflow deflected off the leading edge of the wing causing them to be ineffective. In effect, the wing would block the airflow over the tail surfaces so they wouldn't do anything. In the case of the Bell X1 that Yeager flew, the leading edge of the stabilizer deflected/blanketed the airflow over the elevator, rendering it useless. The fix for that was to tilt the whole stabilizer. In the case of the F4 which was a evolution of the F101 the Tail Surfaces were angled down so they couldn't be blanketed by the wing. No matter what attitude the plane was in some part of the elevator was in the air stream.

With Slugs none of them are all that aerodynamic to begin with. As a result the airflow off the nose is well outside of the tail wad and thus the slug relies on it's weight forward to keep it going in the assigned direction. If the slug tilts enough in flight the airflow can contact the off side and push it back the other way. However it won't tilt it back to the center line it will simply tilt it back the other way until it hits the other side of the airflow. In other words the slug will oscillate back and forth as it travels down range. If the tail wad was truly "In the Wind" the tail would keep the slug flying strait by virtue of drag. Since the airflow is well outside of the tail, it can't happen, and thus the slug relies on it's weight being well forward to keep it on track.

I don't see how a Lyman Sabot slug can fly strait unless it is released from the wad perfectly true to the line of travel. If it is spun, sure. It is weight forward but not nearly as much as Lee slugs or others. The Foster Style slugs have far superior Aerodynamics and the accuracy I've seen from them out to 50 yards is fine from a smoothbore. I got one group that is 1 x 1.5 form the A5 which is not half bad.

Same with round balls which seem to have alot more potential than we give them credit for. If you can get a ball with no Sprue sticking out, it should go down whatever path it was directed on and only be affected by gravity. Seemed to have worked fine for 250-300 years and if they would have figured out that the guns needed decent sights earlier they probably would have lasted longer.

This is an interesting subject and I think we are approaching a more comprehensive understanding every day. I have not seen any definitive source on this subject and if anyone has any published information on Slug Aerodynamics a link to it could be helpful.

Randy

[longbow]

Randy:

I am with you on the oscillation thing. I have felt for some time that a "too long" and "too light tail wad" will result in oscillation. As I mentioned, turbo1889 had some comments about length to diameter ratios and what works best but I believe that was more for all lead Foster style slugs.

The blanketing issue I am sure I have run into as I am sure we all have but in particular when I made my 6 finned slug mould I thought it would work as well or better than a Foster style... Wrong! They did fly nose first but accuracy was quite random where similar length and weight Foster style slugs shot not badly. I believe the "blanketing" kept the air away from the vanes where the solid Cylindrical skirt of the Foster has more surface area to pick up whatever air/drag it can.

I am still thinking that hemispherical or pointy type noses are better than big meplats too but until I test my Moose Minie copies I am, as usual, guessing. Look where that's got me!

Archery is still keeping me from shotgun slugs and will for another week or so, but I'll be back!

Longbow

[W.R.Buchanan]

The area behind the nose of the slug is actually in a vacuum, as the slug moves forward it displaces the air outward from the nose and there is nothing to replace it until the slug is farther down range. Thus the area directly behind the slug is evacuated as the slug travels forward and ambient air pressure is insufficient to close the gap behind it until the slug slows enough to reduce the deflection of the airflow until it hugs the slug more tightly. It never really touches the slug as there is always a laminar layer of non moving air around the slug. Because of this Laminar Layer the slug is actually larger in the air than it actually is.

Same holds true on boats with shiny hulls, the Laminar Layer around the hull is larger than one around the same hull with a rougher finish. Harley Davidson actually figured this out with respect to polished intake ports which were essentially smaller than the same port with a sand blasted finish. Thus allowing a larger volume of air to pass thru the rougher finished port. It was immediately picked up by the Americas Cup Engineers and our crews got busy sanding the bottoms for a flat finish. In the 1968 Races our boat picked almost 1 full knot of speed off wind which in 12 Meter Mono Hull Racing is alot!

This is now Basic Fluid Dynamics.

Randy