Slug design: Past is prologue, from 1963.

[RMc]

"New Slugs for New Accuracy" by George Vitt.

This article traces the developmental evolution of one of the most successful shotgun projectiles designed for handloaders in the smoothbore only era.

Guns magazine, December 1963, page 28.

http://www.gunsmagazine.com/1963issues/G1263.pdf

[jmort]

All of it was fascinating, but as for the slugs, smoothbore groups were really good. Not sure how much progress has been made in accuracy for smoothbores. 2 3/4" x 4" group at 100 yards. It shows the Brenneke has withstood the test of time. What is nice is the detail of the article. Nice to know exact bore dimensions. I was only 4 1/2 years old at the time. Did not realize they had shotgun only zones back in the early 60s. Will have to review a couple more times. Thanks

[longbow]

Thanks for posting that. I saved it for future reading (again).

That has basically been my goal through all of the testing I have done ~ 4" to 6" groups at 100 yards with smoothbore. He did better than that. I have done it with factory loaded slugs and with some commercially produced slugs but not with home made slugs. Sometimes my loads will do it but not consistently enough.

I went the attached wad slug route trying to copy Brenneke slugs some time ago but I have found it difficult to produce the consistency required in my attached wad slugs. I have used jigs to drill and line everything up during attachment but still no go. Or not good enough anyway.

Some of the factory old style Brenneke slugs I have looked at appear to have been assembled before the wad is trimmed to size. Not sure but maybe they are run through a final "sizing" shear after assembly to ensure that the wads are directly in-line with the lead slug.

I think the attached wad material is also a large part of the issue. Maybe I should search out some thick hard felt and give that a go. Wads take a beating and if they distort at firing then stay that way accuracy goes away.

Part of the problem for the home slug maker is material cost, availability and assembly time. So far if it is not readily available, too expensive or too time consuming to assemble I have not considered it viable as I am not about to special order several yards of special felt, spend a pile of money or take more than a few minutes a slug to assemble them.

There are things I haven't tried yet and I will make a few more attempts but at this point I am leaning towards a rifled barrel or at least rifled choke tube to produce the accuracy I am looking for.

It will be interesting to see how things develop in the long range slug thread. I was hoping to add some this weekend but came down with a nasty cold so have not gotten out. I am off work in a couple of weeks and hope to get out slug shooting at least a couple of times.

Longbow

[tomme boy]

Part of the reason for not getting an accurate load is the factory slugs are swaged so there is no imbalance to the slug. That is my thought anyway.

[Hogtamer]

tomme, i've wondered about that. i inquired a couple of times on the swaging site about swaged round balls and got no respect! I do believe that a sprue of any size has got to affect accuracy out of smoothbore. we've got enough to contend with as it is!

[longbow]

Slug shape and consistency must be an important aspect since there is no rifling to stabilize the slug. Any significant imbalance or inconsistent surface has got to cause a tilt of wobble resulting in inaccuracy.

Personally, I think a well cast slug should be as good as swaged but that is my opinion.

Where I find trouble is in the attached wad column. It is hard to get a consistent wad column even using jigs to drill and assemble. Some of the original style Brenneke slugs appear to have been sheared after assembly and maybe that is something to try ~ get it all assembled with slightly oversize wad column then run a sharpened punch over the slug and wad column to shear the wad to slug diameter. Probably easier said than done. I suspect a push through system using a press would work best.

Even after that there is the issue with wads compressing and squeezing to bore diameter then coming out of the muzzle in decent shape because any shredding or uneven compression will affect flight. I can say for sure that stacked and screwed on nitro card wads can delaminate during firing. Hard, dense felt may be the best.

As for round balls, something you can try is to tumble them until the sprue is pounded down. I did this crudely by hand many years ago and when I finished the balls looked like golf balls with no noticeable sprue. Unfortunately they were 0.690" balls and were shot from my 12 ga. Pedersoli choked side by so accuracy was really not there anyway. I have not tried that recently but will. In fact the 0.678" RB's would be a good test subject shot as cast and tumbled for comparison.

I believe the Brenneke style slug is the best design for smoothbore but am struggling with a home production method that is not too time consuming or expensive.

Longbow

[Greg5278]

Somewhere in my Loading Stuff, I have an Article about the Vitt-Boos Slug. It mentioned the Accuracy potential, and the Loads used. I also have the Brochure from Vitt-Boos. The interesting thing was the Article showed that several of the tested slugs had Screws that were way off Center in the Slug, but did not affect the Accuracy. I was going to try them in a rifled bore, but Vitt wrote me and said they may not work well. The Problem was the Rifling is in the same Direction as the Fins, and does not give enough consistent Engagement. Leading or the need to Lube would be another Concern.

Apparently Brenneke Lab tested some of their Slugs, and had erratic Pressures? I cannot verify that, and my Pressure Testing does not prove that Lube has any detrimental effect. Off the wad/Slug Subject, I can't see these Guys still shooting unlubed Factory Slugs in Rifled Bores. They are making a real Mess, and one that often doesn't come perfectly clean. I tried a few slugs of mine, that Leaded slightly, and looked down the bore after Cleaning and Scrubbing with bronze Wool, and other Lead Removers. The Bore looked perfectly clean, but shooting Sabots the Accuracy wasn;t what it should have been. The edge of the recovered Sabots had a little galling or melting where the Land and groove met. I cleaned it with a superfine Glass polishing abrasive, and the melting went away, and the accuracy returned.
Kent, I guess we have to figure out a way to hold the slug and wads together in a fixture to Drill the assembly. Maybe a Collet with a Lever to hold it tight? Then Put the screw in in another operation. BPI also has a Plastic Doughnut type wad that might go nicely under the slug.

I can try and dig out any of the Info if someone wants to try and post it.
Greg
AKA 12 Bore

[longbow]

Greg:

I'd sure like to see the info you have and can scan then PDF and post if you want. I am still working on smoothbores and I know th eBrenneke style slugs work. I just have not come up with a cost and time effective way of making them at home. My glue skirts were doing pretty well but last time out did very poorly with lighter loads. My take is that the glue skirt which is slightly undersize has to "obturate" at firing to fill the bore. With heavier loads that appeared to work and with lighter loads it didn't.

The glue skirts are my poor man's injection molding and the forms I am using are working quite well and producing a nice consistent skirt with minimal effort and cost. (I cam lazy and cheap). At this point I think fit is the issue not skirt consistency but I have to check by making some more slugs and varying skirt fit to wad and fit to bore.

I suppose I should also order some felt wads and try sandwiching them using plastic or heavy leather washers, all assembled in a jig. As mentioned, nitro card wads were not successful for me nor were several other materials I tried. They either distorted or shredded under compression/bore squeezing and when they stay attached to the slug that is bad news.

As for Brennekes and lube in rifled guns, I have an article by Ross Seyfreid on slug shooting from many years ago and he said exactly what you did is that Brenneke factory techs tried all sort of things and found that lubes caused inconsistent pressures. Not sure why but that's what they said. They also questioned why Americans were using rifled guns when the Brennekes worked so well from smoothbores and were not suitable for rifled guns. Apparently the original style Brennekes gave worse accuracy from rifled guns than from smoothbores.

I am a fan of the Brenneke style for sure, I just want one I can make for not a lot of money or time investment. If I don't get there soon though I guess I am going to get a gun with that new fangled rifling stuff.

Longbow

[bikerbeans]

Longbow,


Rifling is just a fad, it will pass soon enough.:roll:


BB

[longbow]

I hope you are right bikerbeans!

I really want to get decent and consistent 100 yard accuracy from a smoothbore... no wild fliers. I would even settle for 8" groups at this point if I could do it on demand. The original goal was 4" but as they say "When all else fails, lower your standards."

What I was hoping to do and probably still will regardless is to make a side by hammer gun into a poor man's Paradox gun by lopping the chokes off and adding rifle sights. Apparently decent regulation can be achieved by filing the muzzles. I may just have to limit my shots to 50 to maybe 70 yards. If that is the case the good 'ol round ball is what I will load and shoot. It is hard to beat the round ball to at least 50 yards.

Longbow

[Greg5278]

Longbow, I guess you have the same Article from Ross Seyfried as I do. It seemed like the Article was him just trying anything to see if something might work. He didn;t seem to be very Scientific about his Approach. Maybe his rifled Barrel 870 wasn't up to the Task. Most of the Full bore slug designs I have shoot very well, and lubed at that. The Pressure results are usually very consistent with little Variation.

Some designs just seem to shoot Poorly in rifled bores, it seems to exagerate the balance problems. I have often seen the holes in the target as olong when fired in the rifled gun, and the groups were larger. Brenneke style, round Balls and hollow base slugs all seemed to have those same tendencies. The Yaw didn't make hitting the target impossible. Groups were still under 4" at 50 yards.

The fullbore slugs That I usually shoot are around 750-770 grains. They shoot around 1" at 50 yards if I can do my part. Recoil is obviously more than the lighter slugs. I haven't seen great results in General with most of the Slug in Wad designs.
The wads are rarely the same thickness on opposing sides, and often shear off the thin petals. According to most Shooters of the Lyman 525, Flyers are common. I worked up the .660 Diameter slug in the CSD wad to try and cut down on those Problems. I had pretty good results, but a few other Shooters did not have the same. I left the wads unslit to stay with the Slug. It saved the cutting and didn't hurt anything. I have the same slug made in both Hollow point, and hollow base versions.
It's too cold to shoot right now 2 Degrees F and 20-30 MPH Wind
Greg
AKA 12 Bore

[hubel458]

I don't think rifling will go away, BUT what it did
was make the process of getting to acceptable and
less costly accuracy 5 times harder, research wise for
non sabot slugs.. Which is why sabots fill in for most
factory slug shooting.Just a quick fix for rifled.
Just an easier engineering process to get what is
close to acceptable.

Back to the smooth if you could get plastic bases with seal
and good, straight crushing, cushion section,
built like on the Brenekke KO slug then
you could cast all kind of weight slugs to attach to it.
But would cost as much as getting sabots made.
And the time.Ed

[RMc]

...the Federal Hunters Journal and Shooting Guide had articles promoting the use of just the bead and groove for slug shooting - if the gun shot to the sights. The reason was simply that shotgun slugs were not sufficiently accurate to merit "sophisticated sights" and five inch fifty yard groups were the best that could be expected.

Frankly, the legalization of "rifled shotgun bore" derailed the further commercial development of smoothbore slugs in the United States.

[longbow]

I think there are several well designed European slugs for smoothbores that perform quite well and certainly good enough for me ~ Brenneke, Gualandi, Ddupleks and some others but they require materials/methods not easily duplicated by the home caster/slug maker.

I am sure that if I machined out all my attached wads, they would be consistent enough to produce good consistent accuracy. I am not willing to spend that much time doing it though.

I did try some slugs in some thick steel shot wads with unslit petals as Greg suggested and since slug fit was good and the cushion leg looked "a lot like the Gualandi" cushion leg I figured these babies would shine! Well, not shine there! Accuracy was quite poor and recovered slugs told me why. The cushion leg collapsed and distorted. Closer examination revealed that while they looked similar to the Gualandis, they were not nearly as robust.

While I have not pursued that approach, there are probably some good solid wads available that would work that way and that makes life easier. However, I live in a reloading component desert and have to order most stuff in so I can't walk into Cabelas or Outdoor Sportsman or whatever and peruse their bags and bags of wads. So I tend to try to make do with what I have or can get easily. In some instances that makes me my own worst enemy!

I will attempt another couple of hollowbase tests and another couple of Brenneke style slug tests then I think I am done. If success does not reveal itself it will be back to the simple old round ball for 50 to 60 yard shooting. If I do get success or even close I will try to refine that system more to see its potential. I am growing weary though. It has been a long haul with few efforts beating round balls to 50 yards. Some but not many and even though I got some excellent groups at 50 yards with some slugs, the groups either weren't repeatable on demand or they didn't hold up at 100 yards.

Longbow

[Greg5278]

Longbow, did you try my slug in the CSD or some of yours? I have them in Hollow base of Smoothbores, and hollowpoint for rifled ones. I'll try and rack my Brain for some ideas. Do you have any HDPE rod available?
Maybe make a profile tool to create a stiff ringed base, and attach the slug to that. I have some Slugs that are HB with a post if you want me to send a few your Way. I was cleaning up my Reloading/Chaos area, and found them. I had so much weight on the shelf it was falling away from the Wall and falling apart. I guess a few hundred# of Lead Projectiles, and some minor Hurricane flooding don't help matters much!
Greg
AKA 12 Bore

[longbow]

Greg:

I used the slug from original prototype mould in some of the un-slit wads you sent. Not sure if they are the CSD wads or not. It seems to me you used the second version larger slug in the CSD wads but that is just by memory.

Almost every slug I have tried with attached wads suffers distortion of slug or wad except Brenneke and AQ. I even recovered some Gualandi DGS slugs that were quite distorted. Accuracy was good for most shots but some keyholed at 50 yards. So if Gualandi has trouble, no wonder I do!

I am sure that a machined wad would be good but I am not about to machine all my wads.

I am thinking I should order some felt wads and try punching and attached those sandwiched between thick plastic or leather washers. Felt is very resilient and shouldn't take a set.

The best accuracy I have gotten from hollow base slugs was from my TC 525 gr. slugs form a home made mould. At 50 yards they grouped into about 3" or better for several 5 shot groups. However, they had to be oven heat treated and shimmed to size for good fit. I never tried them at 100 yards but I guess I should cast some more and see how they do.

My new slug mould uses the same design but is slightly larger in diameter to avoid the shimming. So far it hasn't done as well accuracy wise but it also hasn't had much testing. Also, as before I might find the original groups with the TC slug are not easily repeatable. Been there before!

I'll work on this a little more.

Longbow

[Greg5278]

Longbow, I seem to recall a Company called Southern Felt or something like that here in the States. They were helpful, and have many Punches in stock, and could probably run some easily. Felt is really nice in Wad Columns, but is Pricey for the Real stuff. BPI sells some Synthetic **** now, it punches loasy and is hard to keep in the hollow Base straight. The real stuff compresses in an even manner.
Greg
AKA 12 Bore

[Cap'n Morgan]

Hi guys.

Just stumbled over this: http://www.google.com/patents/US3200751

It's the patent papers for the Vitt slug by George N. Vitt. A lot of interesting reading in there and much technical information. At the bottom of the paper there are some links to other slug patents and a couple of other weird designs. Enjoy!

[Green Lizzard]

i have shot the lee 1 oz and the lyman hour glass till my shoulder was black and blue, never got as good as federal classic in my smooth bores, but i did decide when testing resumes it will be with hard cards and stiff fiber wads. i have a few of the old alcan plastic gas seals that did seem to work well. patched round balls are shooting good enough to keep me from buying federals for now. i was determined but am losing confidence fast.