New slug design

[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.

[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:



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:



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.

[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