Brenneke slugs - light at the end of the tunnel...

[Hogtamer]

Buck Rogers slugs!

[longbow]

Hogtamer:

Not sure if you ever saw these photos:

Rocket slugs sent to me for testing by Diehard. These were commercially made and intended to fit into a shotcup.


Finned slugs from a mould I made. These guys are bore size.

I never managed to get decent accuracy from either. The Rocket slug fins are very flimsy and simply collapsed at firing. The finned slugs had the same problems but not as bad. Oven heat treating solved fin collapse but they still didn't shoot well. Looked pretty cool but didn't shoot well.

Maybe if they were rocket powered...

[Cap'n Morgan]

I love those rubber bullets!

Notice how US standard for less-than-lethal is 426 fps while the European is 312 fps. Are US citizens tougher than the rest of us?

[cpileri]

US cops are less-less-lethal?
C-

[str8shot426]

I love those rubber bullets!

Notice how US standard for less-than-lethal is 426 fps while the European is 312 fps. Are US citizens tougher than the rest of us?

Europeans are a much thinner society. American cops need the extra punch to get through our padding.

[Cap'n Morgan]

Another chapter in the brenneke slug saga.

Good thing first. My right shoulder is more or less back to normal. In retrospect, perhaps going on a pheasant hunt a week after the operation was a bit premature, but the show must go on.

The latest part in the project was making a fixture for aligning the wad with the slug while gluing. At the same time the fixture was used to drill holes in the rear of the wads to lighten them a bit and at the same time moving the center of gravity forward as the slugs had shown a tendency to wobble when shooting at 100 yards.




While the fixture worked just as expected, the modification of the wads was a total failure. Two of three shots missed a 2x3' target at hundred yards.
I dug one of the slugs out of the berm, and from the look of it, the base wad collapsed during launch which would explain the poor precision. These polyester wad are not nearly as strong as the epoxy wads I first made, but much cheaper to make.



So it's back to the drawing board

Next step will probably be an injection molded wad in ABS plastic. (the stuff Legos are made from) This should make for for a much lighter and stronger wad.

If anything, all these experiments has confirmed my belief that the design and quality of the wad in combined shotgun slugs are paramount
to success - any imperfections will show on target. As for the 100 yards wobble, it may be caused by transonic disturbance as the slug speed goes from supersonic to subsonic - in which case not much can be done about it. With a little luck time will tell.

[fred2892]

Nice to see you back capn. I was worried this thread had died as I have been following it with interest.

[longbow]

Can't recall if I posted this pic before but it is of the old BPI AQ slug I have mentioned in other posts.

The finned wad/skirt is a fairly soft plastic like nylon or maybe polyethylene or polypropylene. Not sure exactly what it is. It does squish down quite a bit at firing though and the fins get squashed some but generally retain their shape and the attached wad is still pretty straight and true.

Whatever plastic they are is likely injection moulded.



These are some of the best shooting slugs I have ever shot for sure and I have tried to clone them so far without success, or at least without the accuracy these give.

Since you have CNC equipment available have you thought about machining plastic rod? 3/4" or 20mm would be perfect size to spin out a few in various plastics to try. Might be easier than moulding.

You are way ahead of me at this point and good to see you are still working on it and making progress. I hope to get back to some slug experiments myself shortly.

I must say those are fine looking slugs you are making. Still cast or are you swaging them? They are very nice however you are producing them.

Longbow

[Cap'n Morgan]

Longbow,

Those BPI slugs looks interesting. I just may try something along the line you suggested - probably a design where the slug and wad snaps together to keep things simple. Maybe there's a group buy idea in it somewhere along the way... You know: 500 wads and a mold in a do-it-yourself package.

[longbow]

Cap'n Morgan:

These were my inspiration to try an attached wad slug since they shot so well but they were a bit pricey for shooting many of at around $1.00 CDN each.

My first attempts were "simple":


- made paper tubes that were "bore size" on the O.D.
- drilled 0.690" round balls to put a screw into them (#10 wood screw)
- set the paper tube on the ball with protruding screw head sticking up
- fill tube with hot melt glue (poor man's injection moulding)

Well, it worked reasonably well but of course consistency was not what it could be and groups reflected that.

I have since graduated to doing it all with forms and jigs but still with moderate success.

Machined or injection moulded skirts would be the best way to get consistency in my opinion. However, my beat up little old lathe is not going to be mass producing much of anything so if I were to machine plastic rod to dimensions it would be slow and tedious. That and lack of available materials locally has kept me from going that far.

However, you have an ideal slug for inserting a stem into the cavity and with CNC equipment could make good consistent plastic skirts with a stem to suit the cavity.

The AQ slug is basically a swaged bore size ball with a flat bottom and about a 3/8" (10mm) hole to about 1/2 way through. They are so nose heavy they "stand up" on their noses if you place them on a smooth hard surface.

Anyway, I look at your slug and think that you are there with the slug ~ it is beautiful! All you need is a good wad/skirt and you will have a winner.

I am rooting for you Cap'n!

Longbow

[Mozz]

Has anybody tried plywood as a wad, glues to the base of the slug?

[longbow]

I have not tried plywood but I suspect it would crush and break up under the pressure. A good hardwood plywood might survive and could be worth a try. It would be simple enough to turn some "wads", drill and screw them on. You would need to make a jig to line everything up while the wad is being attached. Also, any little fibers sticking out of imperfections will affect flight (in my experience anyway).

Also, from the results I have gotten with screwed on wads, the slug has to have a fairly long bearing surface of at least bore diameter or preferably longer which leads to heavy slugs unless they are hollow base.

I guess the simple answer there is to look at a cross section of a Brenneke and use the same proportions. It is a proven design.

I think there are several ways and materials that could be used to achieve Brenneke/Gualandi/AQ accuracy but for the home caster/tinkerer, injection moulding is out so machining is next in line and while quite doable it is too much work to be practical except to make a few test slugs up. In my opinion anyway.

The more people in the game trying different things is going to lead to a reasonable solution at some point so get to tinkering and let us know how it goes.

It's all good stuff.

Longbow

[Ballistics in Scotland]

What marvelous work! Somebody has to do it. Any fox that gets culled with one of those, is going to stay culled. I hope I can avoid being distracted by a mental image, possibly perverse, of Henry Daniell dueling with Error Flynn and saying "You'll not be as lucky this time as you were at Panama."

I wouldn't have thought the helical orientation of the ribs would make a difference, and it would be interesting to know if you find differently. Early in the twentieth century there used to be a McLeod slug, long and cylindrical, which had four tapering holes from front to rear, splayed in a slightly helical shape, on the principle that those skewed air-jets, speeded up faster than the slug's velocity... maybe... would spin it. It was found that if it had the energy to spin the bullet enough for stabilization, it slowed it down too much. So if the Brenneke isn't slowed down too much...

Normally it is hitting a bore obstruction that produces the surest and worst kind of shotgun burst. It is surprising what overpressure, if it is only overpressure, you can get away with. The usual theory is that the usual process leading to a ring-bulge or burst doesn't apply to the choke, though. It happens when the slug or shot is slowed down by a collision, and the pursuing gases build up in a cushion of enormously high pressure behind it. But this takes time, and if the obstruction lets the projectile keep on moving, the bulge happens about 3/4in. further towards the muzzle than the slug base was at the collision. With the choke, the slug has exited by that time.

That leaves physical, metal-to-metal impact with the choke. It can happen with steel shot in a soft, thin old shotgun barrel, and assuredly if someone were unwise enough to shoot a ball-bearing larger than the choke (It's been done!) I would want a solid lead ball to pass through the choke by hand. But your ribbed Brennekes should be safe in any choke, and I would be surprised to find improved cylinder giving worse accuracy than cylinder.

If alignment of the wad is so crucial, how about using the slug itself as the bottom of the wad mould? You could introduce some resilience and reduce the quantity of epoxy, polyester, silicon rubber or whatever, by pressing in a mixture of that and cork powder. An electric coffee grinder grinds up noticeboard cork quite effectively. I think it would require a card wad to stop it crumbling away at the edges. Or covering the whole assembly with heat-shrink Teflon tubing could substitute for the ribs.

[Cap'n Morgan]

BiS.

I have tried both felt and paper mache wads with little success, probably because I didn't use a hard card disc, but relied on some rather flimsy double-sided plastic seal wads, where the lip had a tendency to fail under pressure.

I have shot the slugs through a full choke without any problems, but I have also experienced a bulged barrel, caused by an erratic ignition due to a combination of too light a load of Steel powder and a non-magnum primer. My guess is that the primary "explosion" pushed the slug into the start of the choke where it couldn't get up to speed once the second pressure wave hit it from behind. Since then I use only Blue Dot or faster powders, like Herco or Unique.

[hcpookie]

Those slugs' "drag section" look simply like a plastic gear. Like something I'd see on a sewing machine or an RC racing car. It may be worth looking at these smallparts or other kinds of "hobby biy" places for some basic plastic gear sets.

[Cap'n Morgan]

I'll start with an apology to the members in here. The pink color you see in the pictures are the result of having funny co-workers operating the injection machines

The mold for making polypropylene wads are finished and the wads looks promising. The weight for the full length wad is 45 grains and the smaller one 26 grains. Since the small wad is meant to be used on top of a felt wad I have left the cavity fairly open, but it would probably have been better to have the support walls meet in the middle. It can be changed if necessary.

As you can see the full length wad has a solid concave bottom and will sit directly on top of the powder. I still need to make a simple mold for the slug to insert in front, but it is no big deal. I must admit I have high hopes in this design as it will simplify slug loading tremendously (unfortunately high hopes and shattered dreams are often travelling together)

I'll postpone the testing till both types of slugs are ready - then we'll see what happens. Although I have sunk quite a bit of time in this project so far it has been fun and educational most of the way.

[Hogtamer]

Outstanding and easy to find your wads at the range!

[longbow]

Yikes! Let me get my sunglasses... much better now.

While the pink wads are not very manly they look good. And I have to say that is one fine looking slug!

I am hoping the best for you when you test. If that doesn't do it I am not sure what will.

I also have to ask if you have had any problems with ribs collapsing at firing? I have had several versions of my ribbed slugs that seem to tilt in the barrel and I find diagonally crushed ribs ~ leading edge on one side and trailing on the other. Very strange! the first ones had quite thin ribs and only 6 so not a lot of bearing area. My current version still only has 6 ribs but very beefy ribs.

I have to think they are tilting during the jump from a 2 3/4" hull through the forcing cone of my 3" chamber. I have had this happen even with attached wad styles and with hard card wad columns. I am a bit baffled by it.

I notice that the ribs on your slugs are very narrow as with original Brennekes so am curious as to whether you have noticed the same issue.

Looking good Cap'n Morgan and I hope they shoot as good as they look!

Longbow

[Cap'n Morgan]

I have not seen any signs of (unevenly) flattened ribs on recovered slugs. Most of the slugs has been shot from my Krieghoff with 2-3/4 chambers, but with an at least two inch long forcing cone (the gun will easily close on a 3-1/2 empty shell) Of course, the long taper may be more gentle to the ribs, but I have seen no distortion in my Browning either and it has ordinary forcing cones. My slug/wad combination rides pretty tight in the paper hulls I'm using for the moment. Perhaps this is part of the reason I don't have the problem.

[Ballistics in Scotland]

I'll start with an apology to the members in here. The pink color you see in the pictures are the result of having funny co-workers operating the injection machines

The mold for making polypropylene wads are finished and the wads looks promising. The weight for the full length wad is 45 grains and the smaller one 26 grains. Since the small wad is meant to be used on top of a felt wad I have left the cavity fairly open, but it would probably have been better to have the support walls meet in the middle. It can be changed if necessary.

As you can see the full length wad has a solid concave bottom and will sit directly on top of the powder. I still need to make a simple mold for the slug to insert in front, but it is no big deal. I must admit I have high hopes in this design as it will simplify slug loading tremendously (unfortunately high hopes and shattered dreams are often travelling together)

I'll postpone the testing till both types of slugs are ready - then we'll see what happens. Although I have sunk quite a bit of time in this project so far it has been fun and educational most of the way.

What wonderful work! Somebody has to... But I've already said that.

I have always doubted whether long forcing-cones are really an advantage with any kind of load, and more especially with slugs. If I were designing a shotgun specially for slugs, and for shells of a known length, I would do it with an almost sharp step up from chamber diameter, and possibly with an enlarged bore to match the internal diameter of plastic or brass cases.

I'm not sure whether you intend the short wad to stay attached to the slug (like the original Brenneke with felt), or to detach. It has to be one or the other. It's got to be one or the other, and if it is detachment, it ought to happen pretty close to the muzzle. Separation should be certain if the flat top rather than the sloping sides of that short plastic spigot bear on lead. If you need adhesion, the recess and spigot needn't be tapered, but either it should be glued together or the wad moulded in an internally grooved or indented slug - and you can't make it that way with a removable base-pin mould. I think a pair of circlip pliers, which squeeze to open rather than to close, could be adapted to do it.

Attachment 139635

While you might be right about making the internal ribs meet in the middle, I think the chances are that you have done all that needs to be done to prevent collapse of the wad. If heat were that harmful to polypropylenee would surely see its effect on ordinary wads with shot.

Since you already have the moulds for the difficult (i.e. ribbed) part of these injection moulds, I wonder if you have considered making them with a hemispherical recess for round ball? I maintain that it can give accuracy about as good as any slug in a smoothbore barrel, if properly handled. It is the proper handling that is difficult, but such a wad might do better than shot-sleeve ones. In fact is there any reason why the rear recess in the long wad shouldn't be hemispherical, so that it can be used either way round, for either type of projectile?

It is a sobering comment on human nature that if this ever came to be a commercial venture, pink wads would undoubtedly hamper sales compared with brown or green. I think translucent would be most easily made biodegradable. The best seller of all, by a piece of logic which seems pretty bizarre when you think about it, would be one in camouflage pattern. Strange reloading rooms some people must work in! You could even call them tactical, which is surely one of those twenty-dollar words Abraham Lincoln used to talk about.

I certainly don't intend, by making a few suggestions, to criticize some of the most promising work on shotgun slugs I have seen in a long time. There isn't really much that can be shot in the UK with shotgun slugs, except urban legends against them. Even a rare exemption for landowners protecting crops against deer caught in the act, doubtless framed by people who had heard of the kills to cartridges ratio at Waterloo, requires non-spherical projectiles.

But you are causing me to think thoughtfully about an antique of the 1880s that is on its way to me from an Australian auction house. It is a W&C Scott single 10ga sidehammer gun for the 2 7/8in. case, and due perhaps to the punishing effect of light weight, the Damascus barrels are much thicker than they would be in a double. The wood and engraving seem as good as they put on their best doubles, and since people with money usually bought doubles, but didn't spend much on guns that would be taken wildfowling on salt marshes, I nurse the idea that it may have been to Africa or India and seen the elephant.

I wish I had kept my 1950s Lego bricks, surely one of the finest things to come out of Denmark since Prince Hamlet.