Lee 1oz Slug, weird wad impressions!

[fisherboy]

Hi

While doing some experiments with the Lee 1oz slug, a friend and I retrieved some of the wads from the sample rounds.
http://www.fishindserv.co.nz/slug2.jpg

Two strange patterns emerged.

First, the mark from the center bar on the slug is raised, not depressed as we expected.
http://www.fishindserv.co.nz/wad1.jpg

Second, on this wad the slug has clearly made an impression twice, at 90 degrees, one raised and one depressed.
http://www.fishindserv.co.nz/wad2.jpg

Can anyone explain what is happening in the barrel during firing?
How can the bar on the slug leave a raised mark?
What is turning in the barrel, the slug or the wad?

Any thoughts will be welcomed. We are stumped.[smilie=b:


Mark
Christchurch
New Zealand

[onondaga]

My guess without more info from you is that you are trying to put a load together from components you have instead of getting exact components and charge from the Lee instructions that came with the slug mold.

I shoot the recommended Lee load with Accurate #5, Win AA hulls and the specific wad Lee recommends. it always leaves a very deep cleanly shaped impression in the wad and sometimes blows off a wad petal or two.

It looks like you are shooting a light load that is a loose fit because of component selection.

You are getting gas jetting around the base seal of the wad that is blow molding the hot plastic that has just bounced around the slug with a poorly fitting wad/hull selection when shooting the Lee slug.

That would be my guess just from your pictures and question.

My advise is do not "experiment" with 12 ga Lee slugs at all with Hull, wad and powder selection, you could really get hurt or dead. Use Lee recommended loads.


Gary

[Moonie]

What is the exact load you used?

[Doby45]

I think I see an image of the Joker in the second photo. Call the Batman..

[turbo1889]

I can explain the last photo since I have seen this many times myself and have closely investigated the issue. What you have there is a classic forcing cone jump double impression.

Here is basically how it goes (time between each step is micro seconds):
----- Shooter pulls trigger and the firing pin strikes the primer.
----- Primer ignites and begins its burn cycle.
----- Enough heat and pressure builds up to ignite the powder charge.
----- Enough pressure builds up to open the crimp and push the wad and slug inside it out of the hull mouth.
----- Wad is slowed by the forcing cone once the crimp opens before entering the main bore while the slug continues moving forward due to its much greater mass and thus much greater inertia and the base of the slug is no longer tightly up against the base of the wad cup.
----- Pressure behind the wad continues to build and it catches up with the slug in very short order and slams back into the base of the slug like one car rear ending another in traffic. The drive key may or may not be aligned the same way it was during the initial pressure point that opened up the crimp when this happens.
----- Slug and wad continue down the bore together until exiting the muzzle of the shotgun.

This same phenomenon is what causes blown sabots in sabot slug loads (real sabots not wad-slugs like the Lee and Lyman) where the sabot does not hold the boolit or bullet inside tightly enough to prevent this from happening in a shotguns forcing cone. The phenomenon is especially pronounced in guns with rifled slug barrels where the forcing cone constriction on the wad or sabot is further pronounced by the additional constriction and engraving forces when entering the bore and shotguns which have an unusually long forcing cone. Having no forcing cone at all and a rifle like throat in a custom chambered gun nearly completely prevents this from occurring. Gluing the bullets/wad-slugs base to the sabot/wad with that blue silicon gasket seal goo sold by auto parts stores can also cure this issue while still allowing the sabot/wad to separate from the bullet/wad-slug after clearing the muzzle.

I don't know how far the bullet/wad-slug and sabot/wad separate during this kind of situation in the forcing cone and I expect it is probably only a mere fraction of an inch but it is definitely enough to blow both sabots and wads and leave double impressions like this. I have experienced and investigated this phenomenon, Greg a master craftsman of slug hand loading has as well, and James of Dixie Slugs is also well aware of this issue and has experienced product failure in his Tri-Ball loads if the bottom ball is not securely seated in the base of the wad caused by this same phenomenon.

At this time I choose to restrain myself from reacting to onondaga’s predictable Lee brown nosing and usually blah-blah-blah nonsense and choose not to comment on his post at this time beyond the content of final sentence of my post; I am not insulting the Lee slug design when I say that either, the Lee design can be put to good use for some purposes.

[bumpo628]

Where can I find slug data for AA hulls and Alliant Promo powder?

[onondaga]

Here is a link to the instruction sheet for the Lee slug at the Lee site. It is a PDF file and you can zoom in on loads to see them clearly:

http://www.leeprecision.com/cgi-data/instruct/SM%203529.pdf

The load I use with Win AA hulls with a charge of 38.5 grains of Accurate #5, each scale weighed as this is a MAXIMUM LOAD, worked up, and chronographs 1521 fps from my smooth bore Winchester 1300. This load consistently groups less than 2 inches for me at 50 yards.

Gary

[onondaga]

Your insults against the Virgin Mary and the Vatican are unproductive to the post and personally hurtful and insulting to me. I am a Catholic. This month of May is traditionally the month to honor Mary in the Catholic religion and ask for her intersession for those in most need of God's help. I had just finished praying the Holy Rosary of the Blessed Virgin Mary to meditate on the mysteries of scripture and ask for her intersession as I do every day in May and then minutes later turn to your insult of the Blessed Virgin Mary on this board. Please refrain from anti-Catholic bigotry.

Gary

[mckutzy]

turbo1889- Thankyou for the very good break down. I was curious but didnt know what to say about the "jump" cause it did bounce but how. How long did it take for you come to this conclusion.

[plainsman456]

Would having the forcing cone reamed help keep this from happening?
It does look like a double strike on the wad.

[onondaga]

Your theoretical scenario seems accurate except that it does not account for the bulging forward of the impressions of the drive key in the cup. The photo shows damage of the base seal of the wad where it has burned by gas jetting of a loose fit base seal on the wad. The wad failed due to poor fit and gasses jetted around the seal, then blow molded the the cup forward in the area previously compressed against the drive key on ignition.

Had the wad fit properly and not leaked, the forward blow molding would not have occurred.

Had the poster "fisherboy" errored the other direction of fit choosing an unrecommended tight fitting wad instead of an unrecommended loose fitting wad the results would likely have been catastrophic. This is why manufacturer specified hull/wad/charge recommendations should be followed and experimentation avoided . This is not particular to Lee at all and is a standard safety precaution to avoid serious injury or death.

Slugs in a shot cup wad don't react the same as bird shot in a wad cup and the fit and seal of the wad can tremendously affect pressure causing catastrophe with an unrecommended combination.

Gary

[Doby45]

Your insults against the Virgin Mary and the Vatican are unproductive to the post and personally hurtful and insulting to me. I am a Catholic. This month of May is traditionally the month to honor Mary in the Catholic religion and ask for her intersession for those in most need of God's help. I had just finished praying the Holy Rosary of the Blessed Virgin Mary to meditate on the mysteries of scripture and ask for her intersession as I do every day in May and then minutes later turn to your insult of the Blessed Virgin Mary on this board. Please refrain from anti-Catholic bigotry.

Gary

WOW, you have GOT to be joking. Surely you are just looking to be offended. I will leave it at that.

[onondaga]

I am not looking to be offended and not joking. Please refrain from anti-Catholic bigotry and insults against the Blessed Mother. It is very hurtful to me and any faithful Catholic, particularly during May when much prayer is devoted to her intersession.

Gary

[Doby45]

You feel better Gary? I edited it for ya.. Last thing I want to do is offend some poor struggling catholic with my rapier's wit.

[felix]

NO, Doby45, Gary is NOT joking. For your homework, please do a goggle on FATIMA and do your best to adsorb/absorb all of it including the references given within. ... felix

[Moonie]

Might look a little closer, you have also misinterpreted the person that asked for loading info, perhaps you took something else incorrectly.

Gary, I need no loading information and have a number of good loads that I have also worked up, both below your fps for light loads and well above, also with excellent accuracy.

[Doby45]

I made my apologies and will now drop the religious discussion before someone else gets offended. I have zero interest in FATIMA and have no desire to absorb anything about it. Thanks for the 411 though.

[turbo1889]

turbo1889- Thankyou for the very good break down. I was curious but didnt know what to say about the "jump" cause it did bounce but how. How long did it take for you come to this conclusion.

Several years of off and on research and testing including loads specifically assembled to reproduce the situation repeatably by deliberately exaggerating different possible causes in a process of elimination and comparing notes with the two esteemed colleagues I previously mentioned who I consider to have knowledge above and beyond my own in this area.


Would having the forcing cone reamed help keep this from happening?
It does look like a double strike on the wad.

For a rifled barrel slug gun, absolutely not. Extending the forcing cone only serves to compound the problem and no forcing cone at all and a rifle type throat instead is the solution. For a smooth bore, well it depends since smooth bore guns seem to have a mind of their own but usually the same thing applies. That being that the forcing cone is the problem not the solution, although I will say that polishing the forcing cone does usually help, not reaming it deeper rather polishing it to be as smooth as possible without lengthening it. Toothpaste being the preferred polishing medium, with the polishing being done from the breach by rotation of a soft-wood dowel whittled to a slight taper on the end to match the general shape of that particular shotguns forcing cone.


Your theoretical scenario seems accurate except that it does not account for the bulging forward of the impressions of the drive key in the cup. The photo shows damage of the base seal of the wad where it has burned by gas jetting of a loose fit base seal on the wad. The wad failed due to poor fit and gasses jetted around the seal, then blow molded the the cup forward in the area previously compressed against the drive key on ignition.

Had the wad fit properly and not leaked, the forward blow molding would not have occurred.

Had the poster "fisherboy" errored the other direction of fit choosing an unrecommended tight fitting wad instead of an unrecommended loose fitting wad the results would likely have been catastrophic. This is why manufacturer specified hull/wad/charge recommendations should be followed and experimentation avoided . This is not particular to Lee at all and is a standard safety precaution to avoid serious injury or death.

Slugs in a shot cup wad don't react the same as bird shot in a wad cup and the fit and seal of the wad can tremendously affect pressure causing catastrophe with an unrecommended combination.

Gary

I offered no explanation for the second photo with the rib that is bulged upwards instead of the usual impression. I have no solid basis of experience to explain that so I make no attempt to do so.

You are correct that a proper gas seal is important in a shotgun load (or any load for that matter). As to your “reloading book God religion” I would kindly point out that you cannot serve more then one God via your own admission of Catholic faith. Those who write the reloading books are not God and their loads are not scripture. There are book loads out there that are dangerous some so dangerous that they actually get recalled and there are “pet loads” that seriously outperform the book loads and are safer and more trustworthy then many book loads. In fact, as far as shotgun loading goes of all the major commercial loading companies out there Lee is by far the least reverent to the “reloading book God religion”, a simple reading of their instructions they provide with their loading machine and the “universal loadings” sheet that comes with it as well completely throws the whole idea of exact combinations of components completely out the window and basically lets you load almost any shell you want merely divided into two categories by shot weight and powder type and lets you use whatever primer you want and any plastic single piece wad that gives you the correct crimping height.

A guy comes on the forum and makes his first post (probably his last too) and you instantly start assuming that his problem is due to him not following the book loads exactly. Surely no-one that followed a load put out by the ordained “reloading book Gods” would ever have a problem with that load. Oh, no, that just wouldn’t be possible must have been some nut job that dared to substitute a primer or something like that.

Time to get the big religious hammer out and thump the numb skull back into his place. SINNER !!! . . . . . . SINNER !!! . . . . . . THUMP !!! . . . . THUMP !!! . . . . . THUMP !!!

Some of the very best results I have ever seen (not my own work since I fairly quickly migrated over to heavier weight slugs) with the Lee slug were with loads that don’t appear in the Lee data and even dare to use powders not used in any of the Lee loads . . . . . . OH !!! . . . GASP !!! . . . Better call out the Inquisition . . . another heretic needs silencing. They did the same thing to Galileo Galilei. I suppose the original poster can count himself in good company at least, if it’s any consolidation.

[44man]

First I see a recovered wad that is still a WAD---WOW! [smilie=l:
I use the same wad and the Lee loads and the slug expands against the barrel and just rubs all the petals off. I have never found a full wad with all of the different slugs I have.
Foster slugs get any wad of any type blown into the hollow base, the Lee is supposed to stop that but I have never been able to keep petals on a wad.
The best foster slug long ago were the WW loads. I have duplicated the wads and tried every load and powder but the wads blow into the base. I have never figured out how WW did it.
I tried the one sabot that BP came out with and it was miserable.
I understand they have a new one out now but I have not tried it.
Please tell me the load info too.

[jerry_from_ct]

http://castboolits.gunloads.com/showthread.php?t=115839

[fisherboy]

Wow.

Thanks for the input. All of it is appreciated. The load is taken from powder manufacturer ADI, a brand you probably don't get in the US.

Win AA Hull
33.6gn ADI AP70N Powder
Win 209 Primer
WAA12 Wad
And obviously a 1oz Lee slug.

We have quite a lot of sample wads so we will have a really close look at them in view of the info given and see if we can gain enlightenment.

@onondaga - You are correct in that we do not always have easy access to the exact components listed by a manufacturer. With experimentation comes risk! And satisfaction. Your explanation of the raised bar mark may well be spot on. Thank you.

@turbo1889 - Thank you for an excellent and thoughtful explanation of the double strike. Very much appreciated!

Regards

Mark
Christchurch
New Zealand

[44man]

http://castboolits.gunloads.com/showthread.php?t=115839
Yep, I tried the exact things and have all of those wads. I have shot some decent 50 yard groups but can never duplicate them.
I do not hunt with the shotgun but have a Rem 870 with both the smooth bore and a Hastings barrel with a scope. Been fooling with them for years and years for fun.
Every time I get a pattern it is the destroyed wad causing it. I pick up every wad I can find.
James sent me some bore size slugs that worked pretty good but I have not finished testing them, lack of time from other work. The shotgun is just a toy for me. I do not even need one because there are no birds here either and I deer hunt with the bow and revolvers.
I bought some Hammer Head slugs once and actually had several 1" groups at 100 with them. They have a real tough sabot that locks in the slug. I don't want to spend the money! :drinks::drinks:
I don't think a shot wad is tough enough for a slug. I have not tried a real hard alloy either.