MidSouth Shooters SupplyBallisti-CastGraf & SonsInline Fabrication
Titan ReloadingStainLess Steel MediaLee PrecisionRotoMetals2
Page 1 of 2 12 LastLast
Results 1 to 20 of 26

Thread: Need Help/Input for Custom .410 Wad-Slug Mold Design

  1. #1
    Boolit Master turbo1889's Avatar
    Join Date
    Mar 2007
    Location
    Montana, U.S.A.
    Posts
    1,282

    Post Need Help/Input for Custom .410 Wad-Slug Mold Design

    Okay, I use the Lyman 20ga. and 12ga. overgrown airgun pellet wad-slug designs and have got them to produce good to excellent results for my needs in these respective gauges. I have, however, not been able to produce an effective slug load for the .410 that will fill my needs when used in a smoothbore gun. The best load I have been able to develop to date for the .410 consists of substituting a .338 caliber 300gr. (which is 11/16oz.) round-nose, flat-base bullet for the shot inside the wad. When the bullet is loaded backwards and the tail and nose are reversed the resulting wad-slug is slightly nose-heavy and thus the slug flies straight and true out to about the 25-yard line and produces some respectable groups. Beyond that range, however, the proverbial sh*t hits the fan and slugs start tumbling and keyholing. This combination is simply not balistically stable enough without rifling spin to stay flying straight for long. Yah, every ten rounds or so you'll have a volunteer which hits the target straight and very close to the point of aim but that don't mean nothing in a hunting load. Now, I have got this particular load to work like a charm out of the rifled .410 slug gun I built for my little brother using a .303-brit action and a .405-Win. barrel blank. Prints nice tight groups all the way out to 100 yards and he has taken several deer with it in the shotgun/muzzle-loader/handgun only local hunting section. Due to the lower power of this gauge he keeps shots at 70yards or less and does quite well.

    So, I have come to the conclusion that the only way I am going to be able to produce a heavy and slow slug load for the .410 that is stable out of a smooth bore is to have a custom mold cut. Yah, I know it's going to cost me $$$.$$ but as of right now the option is on the table. So I have been figuring and doodling and figuring some more and this is what I have come up with for a tentative prototype for a 5/8oz. SWC .410 wad-slug design:





    The first picture (all of which are central cross sections) shows my tentative prototype wad-slug design beneath a conventional factory 1/4oz. slug. The second picture shows the respective complete slug loads.

    Now, I'm figuring that the first question out of chute is going to be something along the lines of, "Why are you making a 5/8oz slug for the .410? Isn't that like way too heavy of a slug for that gauge?" Well, actually no. Let's go back to shot loads. For the .410 in the 3" shell length there are 5/8oz. "high-velocity" loads with a muzzle velocity of 1,200fps., standard 11/16oz. loads with a muzzle velocity of 1,100fps., and heavy 3/4oz. loads with a muzzle velocity of 1,000fps. Now when you substitute an equal weight wad-slug for the shot in a shot load you end up with a slug load that has slightly higher velocity and slightly lower pressure then the original shot load. Why? Because under acceleration in the bore loose shot has fluid like properties that result in increased pressure and thus friction on the walls of the guns barrel. The wad-slug, however, because it is a single piece of solid lead does not exert this same additional pressure and friction and thus you get the slightly higher velocity and lower friction. Nice trade off, huh !!!

    So, it is entirely possible for the .410 platform to launch a 5/8oz. (275 grain) wad-slug at a muzzle velocity of 1,200fps. But why would you want a heavier bullet moving at a slower speed and the rainbow like flight path that goes with that combination? Answer, because this combination is much better at retaining nock-down power over extended range, and for a shotgun slug load respectable hunting ranges from 50 to 100 yards are for all practical purposes extended range. The biggest, baddest, hottest factory .410 slug load on the market right now pushes a 1/4oz. (109gr.) RN slug out the end of the barrel at about 1,800fps. with a muzzle energy of 784 foot-pounds. That is enough energy for humane and respectable hunting use, however, guess how much of that energy it's still packing at 100 yards? A measly 332 foot pounds, which is woefully inadequate for all but the best placed (or lucky) shot. Now, how much energy would my 5/8oz. wad-slug design still be packing at 100 yards --- a very respectable 664 foot pounds. In fact a standard factory 20ga. slug load consisting of a 5/8oz. RN lead slug leaving the muzzle at 1,600fps. has an impact energy of 752 foot-pounds at 100 yards. That means that in terms of energy a heavy .410 slug load is nipping at the heals of a 20ga. load of the same weight. In fact at even greater range (about 200 yards) it will actually surpass the 20ga. slug load in terms of energy retention performance!!! Not that it would be ethical to take a shot at such range with a smooth bore gun, but this is indeed what the numbers show.

    Now for those of you who think I pulled those numbers out of my, errr where the sun don't shine, here is a link to a respectable, accurate, and easy to use ballistic calculator on the net:

    http://www.handloads.com/calc

    Here are some figures you will need to know (verify if you wish). The diameter of a .410 slug is of course .410 (although most factory slugs are slightly undersize by a few thousandths). The diameter of a 20ga. slug is 0.615 same thing applies about factory ones sometimes being slightly undersize. As far as weight is concerned 1/4oz. = 109.375 grains (109 to keep things simple), 5/8oz. = 273.4375 grains (275 for simplicity). Muzzle velocity of factory .410 slug = 1800fps, for my prototype = 1200fps, and finally for standard factory 20ga. = 1600fps. Factory slugs are round-nosed and my design has a SWC nose design.

    Now, back to my tentative prototype slug design. First off it has a very deep hollow base cavity as well as a healed bullet style base. Both serve to make the slug very nose heavy and thus maintain aerodynamic stability during flight regardless of any spin imparted by the rifling or lack thereof. Secondly, since the vast majority of .410 shot wads available to reloaders such as ourselves are designed for use in both 2-1/2" and 3" shot shells they only enclose the bottom 2/3's or so of the shot column (or in this case wad-slug) when used in a 3" load and the forward 1/3 or so is exposed directly to the bore. My tentative prototype design takes this into consideration and the bottom portion of the slug is sized at about .350" to tightly fit inside the vast majority of .410 wads. The forward head section of the slug is sized at .410 to ride the bore of the gun and is equipped with lube grooves. These lube grooves consist of a series of deep and wide grooves separated by thin bands. This is done so that if the slug is fired through a gun equipped with a choke these thin bands are easily swaged down by the choke (easily compared to a solid head design). Thus the fact that the slug is full bore diameter does not present a hazard when fired in a choked gun. The nose design of the slug is basically that of a SWC with a very shallow angle. This is a direct off-shoot of the nose design used on the Lee "Modern Minie" and "R-E-A-L Bullet" that are designed for use in muzzle loaders at very similar velocities to that of shotgun slugs and have a nose angle optimized to give maximum accuracy and good performance on game at these velocities. For further information on this particular nose style reference page 119 and 200 of the Lee 2nd edition load manual.

    So, I guess that's about it for the blab from me. I need some input from more experienced casters out there on my design. Comments and input on the general design and logic behind it? How thin can I make those bands on the head and how thick do I need to make the cylindrically shaped base to get the mold to full out okay with my intended alloy (soft range lead plus a little tin --- about 40/1 alloy)?

    Thanks, y’all.
    Last edited by turbo1889; 09-30-2007 at 03:02 AM.

  2. #2
    Boolit Mold
    Join Date
    May 2009
    Posts
    6
    turbo1889,
    In the Lyman Reloading Handbook - 44th edition - they show two .410 slug loads, both using a 238 gr slug from a Lyman mold. No pic is shown and no mould # listed either, but velocities range from ~1350 to ~1550 fps, which beat the 240 gr 41 Mag loads and a few others. Any idea where a person could dig up a profile of this slug Lyman refers to?

  3. #3
    Boolit Master

    Join Date
    May 2005
    Location
    Castlegar, B.C., Canada
    Posts
    3,700
    turbo:

    The push out moulds I make are pretty easy to produce if you have access to a lathe.

    I can draw one up for you if you want. A wadcutter hollow base is real easy in whatever diameter you want. A shaped nose can be done pretty easy too. I use an steel insert with nose shape and handle it with a magnet because I am too lazy to make a more complicated mould.

    You have seen my finned slug. That was cast in a push out mould that was very easy to make. The wadcutter and TC slugs I showed there were made in a push out mould too and those hollow base slugs work as well as slugs from any other Foster moulds I have tried.

    Unfortunately the finned slug was a flop but I soldier on! That mould will be casting bore size Fosters shortly and ribbed hollow base (kinda look like Brennekes) when I get time to bore out the finned mould insert some.

    The link is here:

    http://castboolits.gunloads.com/show...t=50599&page=2

    Let me know if you want a drawing.

    Longbow

  4. #4
    Boolit Master turbo1889's Avatar
    Join Date
    Mar 2007
    Location
    Montana, U.S.A.
    Posts
    1,282
    Wow !!!! Posted that over a year and a half ago and just now got a response. Incredible -- boy have things progressed in this particular project since then.

    Well first off I guess I should start by addressing the first response:
    Quote Originally Posted by 40cal View Post
    turbo1889,
    In the Lyman Reloading Handbook - 44th edition - they show two .410 slug loads, both using a 238 gr slug from a Lyman mold. No pic is shown and no mould # listed either, but velocities range from ~1350 to ~1550 fps, which beat the 240 gr 41 Mag loads and a few others. Any idea where a person could dig up a profile of this slug Lyman refers to?
    Unfortunately, I have already examined that particular option and found it to actually be a miss-print. The defunct and no longer produced Lyman 410 slug mold actually produced a simple foster type slug that weighed 138gr.

    The design I put forth in my original post turned out not to work. The thin walled hollow base part that fit inside the wad simply could not sustain the structural stress during firing even when cast from 20+ BHN type-metal. Design was a failure but valuable lessions were learned.

  5. #5
    Boolit Master turbo1889's Avatar
    Join Date
    Mar 2007
    Location
    Montana, U.S.A.
    Posts
    1,282
    As to where my current designs parameters are now. Well a picture is worth a thousand words:






















    And, as soon as swage die punch #4 is done next step is to put a solid 200+ grain rifled slug head on top of the plastic finned, diablo tail.

  6. #6
    Boolit Master

    Join Date
    May 2005
    Location
    Castlegar, B.C., Canada
    Posts
    3,700
    Pretty slick!

    I can talk a lot about slug skirts and fins not standing up to the forces of firing! In the end my finned slug oven heat treated and well cushioned did survive firing but did not produce any sort of accruacy at all.

    My next try will resemble your 410 slugs only in 12 ga. ~ ribbed hollow base but due to my mould the full bore band will be at the nose instead of the base.

    I think a long bore contact slug with an attached skirt Brenneke style is the best way to get good accuracy from a smoothbore. Making consistent skirts is the problem there (or at least for me). Where did you get those tails?

    Longbow

  7. #7
    Boolit Mold
    Join Date
    Mar 2009
    Posts
    7
    turbo1889,
    How did you come up with using a .338 caliber boolit mold? I was thinking of doing the same thing.

    Thanks,
    Scout

  8. #8
    Boolit Master
    Join Date
    Feb 2009
    Location
    NH
    Posts
    303
    How hard would it be to make a mold like this? Would this design actually work in a .410?





  9. #9
    Boolit Master

    Join Date
    May 2005
    Location
    Castlegar, B.C., Canada
    Posts
    3,700
    diehard:

    Take a look at the link I posted above. I made a mould that casts a slug very similar to that but with 6 fins. It is actually quite easy to make and casts well.

    So far the problems have been that even with air cooled wheelweights the fins crushed when the slugs were loaded over hard card wads and once I solved that by heat treating, cushioning better and reducing charge somewhat I certainly didn't get anything resembling accuracy.

    My thought is that the fins travel in the partial vacuum created by the shockwave in front of the nose so are not really effective. A Foster style has a broader surface exposed to the air when it tips. That is my thinking anyway.

    The two finned slugs in the middle of the photo were recovered from our 300 yard berm after bouncing along from about 100 yards. They are virtually undamaged due to heat treating but were going through the paper sideways at 50 yards.

    I have made several hollow base moulds and all have worked reasonably well. This one did not.

    Have you tried loading and shooting any of the Rocket Slugs? If so how did they shoot?

    If those work then mine should unless there is inaccuracy in the mould. In any case so far mine are a bust ~ but they sure look cool!

    Longbow

  10. #10
    Boolit Master
    Join Date
    Feb 2009
    Location
    NH
    Posts
    303
    I haven't tried the Rocket slugs yet, but I hope to soon.

    I follow your posts with much interest longbow. I'd like to make a mold myself of any kind (just for the sake of doing it) that gives reasonable accuracy. I lack machining equipment, but I do have a friend at the local voc tech school who loves to play with his toys. Someday I'll hit upon something, maybe. Until then I keep trying to tinker and plug away. I admit I haven't been loading shotshells long (loaded 30-30 win amd 8mm for years), so I have a lot to learn.

    Thanks for your reply.

    I'll be sure to let you know when I shoot the Rockets (if I win them on auction, that is).

  11. #11
    Boolit Master turbo1889's Avatar
    Join Date
    Mar 2007
    Location
    Montana, U.S.A.
    Posts
    1,282
    Quote Originally Posted by Scout82 View Post
    turbo1889,
    How did you come up with using a .338 caliber boolit mold? I was thinking of doing the same thing.

    Thanks,
    Scout
    For a gun with a tight choke the 0.338" bullet is the way to go. For a gun with a little more open choke 0.348" diameter bullets inside the wad in backwards position will work even better. They are a just a smidgeon tighter so they fly straighter farther. Harder to find though, since only one cartridge made my Win. ever used that diameter of bullet.

  12. #12
    Boolit Master
    Join Date
    Feb 2009
    Location
    NH
    Posts
    303
    I shot 15 of the Rocket slugs yesterday (along with 100 othrr home-rolled slugs), and like I promised above I am just reporting on their effectiveness. I apologize for lack of pictures, but I accidently threw away the targets with the others I was using. I even threw away my bragging targets, so I'm bummed.

    Anyway the old Rocket Slugs averaged 406 grains, so I choose three 1oz loads from Sapp's Reloading for Shotgunners. I went with the following recipes hoping the hull would make the difference I guess:

    1. 25.5 grains of SR 7625, Win 209, Fed 12S3 in a Fed. GM hull ...1255 fps, 6,600psi
    2. 24.0 grains of SR 7625, Win 209, Fed 12S3 in a Rem Nitro hull...1250 fps, 7,900psi
    3. 25.0 grains of SR 7625, Win 209, Fed 12S3 in a Win AA hull ...1250 fps, 7,100psi

    My first shot at 25 yards was with the Fed GM loads through a Mossberg 500 using an IC choke. Aiming at a 2" square, the round impacted in the dirt pile almost a foot above the target frame. Adjusting my point of aim, I managed to hit the target 7" above the 2' square and 5" to the right. At this point I decided to go with more choke.

    The next three Fed Hulls were shot from my favorite slug gun: a JC Higgins model 20 with a fixed modified choke and a Redfield peep site. Still at 25 yards and aiming at 6'Oclock on the
    2" square, I put three Rocket slugs into a group a little over 2", right at point of aim.

    The next five shots were the Rem Nitro loads fired from the modified choke at 25 yards. Three of the shots hit the 2"square, and a fourth shot hit just outside it. Very tight. A flyer on the fifth shot made the groups size just over 5" though.

    I fired one of the Win AA loads at 25 yards and hit the 2" square. Then fired my remaining four rockets at a 2" square on the 50 yard target frame. The first two shots hit the 2" square...and probably because the shooter is a moron, the last two scattered into a 12' group.

    Anyway....the point is that although these slugs really did no better than the Lee and Lyman slugs I was shooting yesterday, they did okay. They definitely need to be fired from a choked gun, and may have benefited from a slower powder. Hull choice really made no difference that I could see. I wish I had more to try at 100 yards, but I didn't.

    To bring this back to the point of the thread, I'm still wondering if a finned .410 slug wouldn't be worth trying.


    BTW...I have 5 Rocket slugs left, plus the old box. I know you have experimented with finned slugs Longbow...if you want the remaining 5 slugs I will send them to you for free for you you to check them out. PM me. Also any collecter out there who might want the the old box for free PM me.

    regards,
    diehard

  13. #13
    Boolit Master

    Join Date
    May 2005
    Location
    Castlegar, B.C., Canada
    Posts
    3,700
    diehard:

    Did you recover any of the Rocket slugs? I am wondering how they looked after shooting. Any signs of fin collapse?

    I figured my cast finned slugs had enough fin area that they wouldn't collapse but I wound up heat treating, cushioning and downloading to reduce pressure. Also, I was using Blue Dot which is fairly slow powder. In the end they shot fine and didn't collapse but I didn't get anything resembling accuracy.

    I doesn't look like the Rocket slugs have fins any thicker than mine. Did you check hardness?

    What did you use for wad column? I used a plastic gas seal, hard card wads then 3 polyethylene disks under the slug as card wads were shredding into the fins.

    I was about to modify the mould to make a more traditional Foster style but with thick skirt and with ribs to allow for making a tight fit and to allow choke usage. Maybe I had better try the finned slugs again!

    Nose shape may be an issue too. The Rocket slug looks a little more streamlined than mine.

    Interesting stuff.

    Longbow

  14. #14
    Boolit Master
    Join Date
    Feb 2009
    Location
    NH
    Posts
    303
    Longbow,

    I didn't dig out the slugs from the sand pile behind the targt frame, although I probably could have since no one else was at the range. Didn't even occur to me.

    My wad column consisted of simply inserting the slug into a F12S3 shotcup, just like the "directions" on the back of the box suggests.

    I'm serious about sending you the last 5 slugs. I'm interested in what information you can get from them that I (in my newbee ignorance) have failed to provide. Your attempts at finned slugs look like they may be viable to me, especially in regard to the .410. I am very curious about that design.

    PM me with an address and I will put the slugs in the mail. Only thing I ask is a report back on how they did for you.

  15. #15
    Boolit Master

    Join Date
    May 2005
    Location
    Castlegar, B.C., Canada
    Posts
    3,700
    Well, that answers one question then ~ they are design to fit into a shotcup.

    Mine is bore diameter. I really thought they would do better than they did.

    Possibly the nose size and shape of the Rocket slugs is more aerodynamic allowing the air to flow around and over the fins? I can change the nose shape of my mould some. I could also go to 4 fins instead of 6 which may make it more nose heavy though balance point is pretty good now.

    If the Rocket slugs do work at least as well as Fosters they have some benefits like they should go through any choke even if they are hardened since the fins should swage to size. Should be applicable to any bore size. I like the solid nose ~ also a reason I made the finned mould.

    Testing continues!

    And back to turbo's thread ~ how are those working for you? It looks like a nice set up.

    Longbow

  16. #16
    Boolit Master turbo1889's Avatar
    Join Date
    Mar 2007
    Location
    Montana, U.S.A.
    Posts
    1,282
    Quote Originally Posted by longbow View Post
    . . . . And back to turbo's thread ~ how are those working for you? It looks like a nice setup. . . .
    Very Good - For a full report look over the contents of this thread in the swaging section of the forum:

    http://castboolits.gunloads.com/showthread.php?t=41865





    Here are some teaser photos:


















  17. #17
    Boolit Master

    Join Date
    May 2005
    Location
    Castlegar, B.C., Canada
    Posts
    3,700
    Got to say I am impressed!

    That is a pretty nice bit of equipment you have there.

    I am still working on slug loads and had put the finned slugs on the back burner but diehard got some good results from his Rocket slugs so I guess I will resurect the finned slug project.

    I am thinking that possibly the nose on my slug was too blunt to allow air flow over and through the fins.

    I was heading in a direction much like yours in making a finned slug mould that would have an attached wad with the fins (or more accurately ribs) included simply to allow shooting through a choke and to reduce barrel friction.

    I still think it is likely the best way to go. Brenneke had it sorted out about 100 years ago. I have had trouble making consistent attached wads though. I like your set up!

    My finned slug mould can be converted to produce a ribbed slug like yours with the exception that the "driving" band will be at the nose instead of the base.

    I will try some more finned slugs but if they are not successful, I will be following in your footsteps.

    Longbow

  18. #18
    Boolit Master
    Join Date
    Mar 2005
    Location
    East Coast
    Posts
    373
    Turbo, did you have the Diablo bases machined? How do the Mold blocks look that were made?
    I am still working on the 660 diamtere 625gr 12 ga HP in a wad.
    Greg

  19. #19
    Boolit Master turbo1889's Avatar
    Join Date
    Mar 2007
    Location
    Montana, U.S.A.
    Posts
    1,282
    Quote Originally Posted by Greg5278 View Post
    Turbo, did you have the Diablo bases machined? How do the Mold blocks look that were made?
    I am still working on the 660 diamtere 625gr 12 ga HP in a wad.
    Greg
    If you are referring to the plastic fin bases for some of my 410 slugs those were cut on a rapid prototype machine by McBirch for me. As far as mold blocks go the ones Brian made for me are beautiful. Probably won't get the cavities I want cut in them done for a while though, my "Projects" fund is almost completely depleted as of present. I had that custom swage die for the 410 slugs made, ordered molds for making swage cores for it, have two full bore Dixie style 12ga. molds being cut for me by Brooks Moulds, bought those extra large blank blocks from your friend Brian, and on top of all that bought a used bottom pore pot that is actually decent size (holds 50+ pounds) and has a decent bottom pore system that fills big 1+ oz. slug molds in about a second flat and doesn't drip - lot better then being able to whistle yankee doodle with a regular bottom pore while the mold fills. Long story short that all used up well over a grand out of that "Projects" fund; so there is going to be a pause period in place for a while towards new development. Time to fully finish what ones I've got on the burner, let the savings account build back up, and finish the CAD prints for the cavities I'm going to have cut in those two oversize blocks from Brian. Since I'm having the full bore molds for rifled barrels cut by Brooks Moulds I'm planning to use those blocks for my idea for a smooth bore slug with four longitudinal ribs that bring it to full bore diameter and allow it to be cast of hard WW alloy and still swage down easily and safely in a choked gun. I intend to make one the exact same weight and length as the Lyman 12ga. foster only cast from WW so it can be used with the same load data and the other one is going to end up a slightly larger size of the same design for use in smooth bore 10ga. guns. These designs will require a two step process to cut with the main mold cavity being cut via a lathe boring and then the two mold halves will need to be milled with a small diameter ball end mill cutter. Definitely, work best done by a custom machinist rather then your average mold cutting outfit.

  20. #20
    Boolit Master
    Join Date
    Feb 2009
    Location
    NH
    Posts
    303
    I'm seriously impressed. I'm not only not even in your league, I feel like a T-ball player looking up at Derek Jeter. I can't wait to see how all this turns out. Sounds to me like some new options for us smoothbore shooters!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Abbreviations used in Reloading

BP Bronze Point IMR Improved Military Rifle PTD Pointed
BR Bench Rest M Magnum RN Round Nose
BT Boat Tail PL Power-Lokt SP Soft Point
C Compressed Charge PR Primer SPCL Soft Point "Core-Lokt"
HP Hollow Point PSPCL Pointed Soft Point "Core Lokt" C.O.L. Cartridge Overall Length
PSP Pointed Soft Point Spz Spitzer Point SBT Spitzer Boat Tail
LRN Lead Round Nose LWC Lead Wad Cutter LSWC Lead Semi Wad Cutter
GC Gas Check