New full bore slug

[megasupermagnum]

I ended up buying cast bullet design software, made by member Tom Myers. I got the basic, and it works well enough, I'm not sure it's worth its price though. I was under the impression it could estimate ballistic coefficient's, but it seems only the professional version may do that. Anyway, I decided to use it to draw a slug I've had rolling around in my head for a while. I wanted to get the longest bearing surface I could on it to reduce the jump to the rifling as minimal as possible. I hoped to keep it a bit lighter, but 725-760 grains depending on alloy is ok. Taking a cue from other bullet designs, I put a meplat of .500", just over 68%. Small meplat's are a complete waste on a shotgun slug, and is my biggest fault with my Accurate 73-770S. I feel like a tangent ogive with no shoulder should provide the best self-aligning in this case. I'm not scared of the slug jumping the crimp at all, most factory rifled slugs are the same without problems. Along with the weight thing, I wanted the lightest weight I could, so I think a hollow base is the best way to do that. The walls should be plenty thick, and nose left thick so that it does not deform on firing or impact. I'm not sure how the balance will effect it, I would think if anything it would help. Anyway, here is the slug I'm hoping to have Tom (Accurate molds) make, and then sent for a hollow base pin. Don't be afraid to criticize. Presumably, I could have multiple base pins made. How thin do you think I could go?

219013

[bikerbeans]

Mega,

One thing to check is Tom has some dimension restrictions on depth of the grooves and the angle of the grooves. I don't remember the numbers but if you open his design a mold it lists them.

The wider the nose the better in my book. Easier to roll crimp and makes a big hole.

Regarding skirt thickness, if you want the skirt not to collapse then I would plan on heat treating the slug. I know folks fill the cavities of the HB slugs, but in my mind that's just adding another variable to the load. Few components means fewer chances for error.

I have a couple of HB slug molds and both base pins have tapered sides and a flat point. I know you want a fair amount of taper if you want the slug to release easily. I don't know why the point of the pin is flat.

BB

[megasupermagnum]

I agree, I never did like the idea of filling the cavity. I was either going to heat treat, or cast with linotype, probably heat treated 94/3/3 alloy. I should be within Tom's tooling abilites. The groove angles are 55 degrees, and the depth is the same as his other slugs. I did not see an option for a flat point hollow cavity in the program, although there is a decent taper to the whole thing. I'll mess around more, and see if I can't get a flat point, that may lower the slug weight even more.

Edit:
It seems the program can only do rounded top cavities, but I'm sure Erik at Hollow point molds can set me right. The very odd thing is as far as I can tell, I never touched anything, yet now it's telling me the estimated weight is 671 grains with the same alloy. I'm not sure how much I really trust the program, but that would be fantastic if true.

[bikerbeans]

94/3/3 alloy heat treats harder than blazes!

HP Molds can make you a pin that will also allow you to cast a solid base slug. This is a good option in case you decide to hunt cape buffalo.:bigsmyl2:

BB

[megasupermagnum]

No kidding. A plain base is calculated at 950 grains! Now the hollow base says 760 grains again, so I'm going to assume that is the weight with the hollow base shown. I've never heat treated anything, but I've water dropped some alloy. I had some lyman #2 water drop at 26 BHN, so I can only assume heat treated 94/3/3 should be close to linotype hardness. I certainly won't be seeing any expansion.:bigsmyl2:

[missionary5155]

Good afternoon
That looks like death waiting to strike !
What if it was poured from zinc ? I understand the desire not to contaminate a mold with zinc but it would be light and probably the skirts would withstand any pressure applied in a shotgun.
Mike in Peru till June

[uncle dino]

Mega ... BC is in lower rt hand corner. .12 looks about right for that slug..not sure if pic is from your software or accurate molds though..d

[megasupermagnum]

Mega ... BC is in lower rt hand corner. .12 looks about right for that slug..not sure if pic is from your software or accurate molds though..d

D'oh! Good catch. Now I'll be checking out different bullets for hours looking at the BC. I had to name the slug something, so I just put in an Accurate molds number. So far Tom has had nothing to do with it, I created that slug myself on a program that I'll link below. I'm hoping somebody will catch any mistakes of mine before I have the mold cut.


http://www.tmtpages.com/draw/draw.htm

[bikerbeans]

Heat treating with the right alloy is easy. With 94/3/3 I use 450F for 30 minutes and immediately dunk them in a 5 gal pail of water. I use a cheap toaster oven and my thermo couple, SSR and PID to control temp. I drilled a hole in the top of the oven and insert the thermo couple right above the slugs.

BB

[longbow]

Looks okay to me though I think i'd go a hemispherical RNFP... but then I am thinking smoothbore. Things are a bit different for rifled gun.

As for the HB and skirt, I'm with BB on it likely being best to heat treat. I haven't run into a skirt yet that hasn't deformed some if not heat treated no matter how thick it was, and still looked like an HB slug anyway. I fill the cavities partly to support the skirt but mostly to keep wads out of the cavity. Heat treated or not if the slug has a hollow base wads will try to get in there, even nitro card wads. You could copy the Lee Drive Key or get a tapered hollow bored/reamed into the core pin like the Russian Paradox slugs so the skirt could be thinner but the wad would be stopped by the central pin.

I wouldn't go any thinner on the skirt than 0.100" ... at least without a pin or "key", but that's just me.

If you don't fill or use the key/pin idea then put a tough disk like polyethylene under the slug. That should keep wads out.

As for weight, you could lighten some by using just two driving bands and leave a wide, and deep as Tom can cut, groove. The old Paradox slugs had a huge groove! They were solid body so heavy even if they were HP'd but a hollow base design would lighten them a lot. I've always liked the Paradox design:

https://www.classicshooting.com/collections/holland-holland-sporting-cartridges/products/nitro-paradox-ammunition-for-paradox-guns?variant=1179491392

I'd stay away from too large a flat on top of the pin. I made mine fairly flat so keep lead in the nose but if I don't tip the mould a bit while pouring I often get a little cavity at the top due to air trapped over that big flat. Bubbles seem to flow off a radius or point but seem to hang onto the flat... at least in my mould. I think your radius looks good.

That slug would probably shoot just fine as is from rifled gun.

Longbow

[megasupermagnum]

Looks okay to me though I think i'd go a hemispherical RNFP... but then I am thinking smoothbore. Things are a bit different for rifled gun.

As for the HB and skirt, I'm with BB on it likely being best to heat treat. I haven't run into a skirt yet that hasn't deformed some if not heat treated no matter how thick it was, and still looked like an HB slug anyway. I fill the cavities partly to support the skirt but mostly to keep wads out of the cavity. Heat treated or not if the slug has a hollow base wads will try to get in there, even nitro card wads. You could copy the Lee Drive Key or get a tapered hollow bored/reamed into the core pin like the Russian Paradox slugs so the skirt could be thinner but the wad would be stopped by the central pin.

I wouldn't go any thinner on the skirt than 0.100" ... at least without a pin or "key", but that's just me.

If you don't fill or use the key/pin idea then put a tough disk like polyethylene under the slug. That should keep wads out.

As for weight, you could lighten some by using just two driving bands and leave a wide, and deep as Tom can cut, groove. The old Paradox slugs had a huge groove! They were solid body so heavy even if they were HP'd but a hollow base design would lighten them a lot. I've always liked the Paradox design:

https://www.classicshooting.com/collections/holland-holland-sporting-cartridges/products/nitro-paradox-ammunition-for-paradox-guns?variant=1179491392

I'd stay away from too large a flat on top of the pin. I made mine fairly flat so keep lead in the nose but if I don't tip the mould a bit while pouring I often get a little cavity at the top due to air trapped over that big flat. Bubbles seem to flow off a radius or point but seem to hang onto the flat... at least in my mould. I think your radius looks good.

That slug would probably shoot just fine as is from rifled gun.

Longbow

A lot of it was just done by eye, I think that nose looks right on there. I just want to try some kind of round nose to see if I can't squeeze that last bit of accuracy out of the gun verses a sabot or wad cutter type full bore slug. I've been getting consistent 5" groups with some coming down to about 3 1/2" with the Accurate 73-770S now that I've dialed the loads in better. I could keep trying for those sub 3" averages, but they don't seem as devastating as they should due to the small flat point. I have no doubt they are more than lethal, but if I'm going to punish myself in recoil, and they are in pain in the butt to cast, I may as well throw a hammer of a slug. Plus you can bet I'll try the hollow base in a smooth bore as well. That would really be some bear medicine!

Back to the looks of the slug, I did try just one big lube groove, and it just looks wonky. If I want lighter weights, that slug says it should be about 725 grains when cast of linotype, and 740 gr with Lyman #2. I'm going to try some of the 73-770S's over the chronograph again soon, as I have a feeling I am getting awful close to 1300 fps with them and Bluedot. I gave up on Remington hulls, it turns out they are softer than anything. I got failures to extract at 34 grains. With Fiocchi hulls, I was starting to get an extractor dent at 36 grains which should be in the ball park of 11,000-12,000 psi. I've now gone to Federal hulls, and at 36 grains, they are spotless. I'm thinking of pushing it to 38 grains and seeing how fast that is.

[uncle dino]

I've had the pro edition for a year and I'm still learning...I do believe you can trick the program and do a flat base pin. It'll give you an error, but it'll still calculate.. I'll have to re check how I did it..d

[catboat]

I am interested in slug loading my 12 and 20 gapump shotguns. I’ve been reading and reasearching designs and loading notes from those who have done it,

Looking at your slug design, one thought came to mind based on my reading. I seem to recall reading that it was beneficial to have a flat ledge on the outer front rim of the slug ( sort of like the shoulder on a Keith style bullet, but with a wadcutter,minimal pronounced center meplat). Evidently ledge this allows a roll crimp to release/unroll upon firing and not create pressure spikes if the accelerating slug( that does not have a flat rim ledge, and is more “ rounded” going from meplat to slug side like your design) would “ catch” the roll crimp and get jammed between the slug and barrel.

I’m no expert on this, but I just recall reading about this design element ( flat ledge on outer rim on front of slug) being a good thing/ desired/ recommended for avoiding pressure issues. Just a friendly comment-not a criticism.

Good luck. Looking forward to following your progress with this project.

[megasupermagnum]

I am interested in slug loading my 12 and 20 gapump shotguns. I’ve been reading and reasearching designs and loading notes from those who have done it,

Looking at your slug design, one thought came to mind based on my reading. I seem to recall reading that it was beneficial to have a flat ledge on the outer front rim of the slug ( sort of like the shoulder on a Keith style bullet, but with a wadcutter,minimal pronounced center meplat). Evidently ledge this allows a roll crimp to release/unroll upon firing and not create pressure spikes if the accelerating slug( that does not have a flat rim ledge, and is more “ rounded” going from meplat to slug side like your design) would “ catch” the roll crimp and get jammed between the slug and barrel.

I’m no expert on this, but I just recall reading about this design element ( flat ledge on outer rim on front of slug) being a good thing/ desired/ recommended for avoiding pressure issues. Just a friendly comment-not a criticism.

Good luck. Looking forward to following your progress with this project.

It's a good question, and one I barely mentioned in my first post. The ledge does give the roll crimp something to seat on, but its usefulness is overrated. I would guess it is possible for undersized slugs to become a problem, but a full groove diameter slug can not jump over the crimp. Consider that most, if not all factory rifled slugs are essentially a round nose with no shoulder besides the beginning of the rifling. They are all roll crimped, and never once has it been a problem. In a gun with a proper throat (good handguns and rifles), I've come to be a big fan of SWC's. The shoulder's main purpose is to align the bullet in the throat, and then the bore. Down range, the shoulder will cut a clean hole in paper. That fact, along with the fact that they will generally shoot very accurately at very low velocities makes them fantastic for target shooting. They can also be driven faster than most bullet designs, and with a large meplat, make awesome hunting bullets. None of this really applies to shotgun slugs for a number of reasons. The two big ones are because a to-scale bullet in 12 gauge would be too heavy to be reasonable, think 1500+ grains. The second reason pertains to just the shoulder. Shotguns don't have throats. Without a proper throat, a SWC does not center itself as well as a round nose design. I have no doubts about that fact, but how much it will truly effect accuracy? The only way to find out is to pull the trigger.

[megasupermagnum]

The mold is now in the Accurate Molds catalog, and I am just waiting on a reply from Hollowpoint Molds.

[longbow]

You should be fine with the round nose. As you say, most factory slugs are round nose and without any flat shoulder.

My first time out with 0.735" RB's I was wondering if they might run over the crimp but no problem at all. In fact I've found it a bit odd that even slugs like the Lee Drive Key wad slugs will open a roll crimp just fine... or so it seems anyway. I've had no problems with them running over crimps or petals on wad being damages which is what I expected.

It'll be interesting to see how that slug does but I am thinking in a rifled gun it will work very well.

Longbow

[finstr]

My knowledge of slug design is quite limited so take this idea with a grain of salt please.
I think the slug looks great and I personally would powder coat them as its a full bore size to stop any leading of the rifled bore. I run really soft pure lead thru my .45 and .38 and so far thru my 12ga with no leading at all.
Also the cavity in the base would be interesting if you took a page out of Lightfield's book and created a more cylindrical void with a small bump around the rim to attach an impact discarding type wad that stays with the slug during flight. Now the Lightfield wad has a protrusion that snaps into the cavity and acts like a set of vanes on an arrow to guide the slug thru its transition from supersonic to subsonic keeping it semi-stable thru the shockwave. At least that's my understanding of it. Of course we can't buy those wads but someone with a 3D printer might be able to make something like that.
I can post pics of the Lightfield slug and wad as I have a couple here someplace
Just a thought...

[megasupermagnum]

Not a bad idea, and no need for pictures. I've shot, even reloaded Lightfield slugs. They are good, but never anything spectacular. I always had better results with brenneke slugs, with rifled or smooth bores. You can buy exactly what you describe, just look up all the Russian slugs these guys are talking about. They are various designs that go on a wad with a post. You can buy those wads, but they have to be imported from Italy (Gulandi). That design has it's own set of problems, like anything. If you could get a CONSISTENT sabot to load, I think that would be a good way to go. The problem is I have never seen one that shoots well stick around more than a year or two, especially factory ammo. I never had anything other than good enough results with any kind of wad slug. I really think a full diameter bullet is the way to go for my purposes, and I am looking for consistent sub-3" groups at 100 yards. I've tried powder coating, it's not for me. In handguns, it's more work, and I actually prefer the smell and smoke. I haven't messed much with cast in rifles, but I get zero leading in 30-30. With shotgun slugs, I didn't add any kind of lube to my last batch (Accurate 73-770S). I'm now up to about 50-60 shots, no lube at all, no cleaning the bore and leading is very minimal. Gas cutting isn't and issue, and if I heat treat these next ones, I just don't see any reason to worry. The hollow base puts the weight forward slightly, which may help with stability. I've been shooting some 770 grain plain base slugs at 1200-1300 fps, and still get 4-5" groups at 100 yards (5 shot CTC averages) which is about as good as anything.

[bikerbeans]

Mega,

Did your new mold arrive?

BB

[megasupermagnum]

No. I ordered two molds about 3 weeks ago, and have not seen either. One for handgun coming right to my door. The slug mold is going straight to Erik, and I'm guessing he must take 3 weeks or so to do his thing. He is not doing regular pull out pins at the moment, so it will be an in-mold pin (insert bar?). Because of this, the taper will have to be increased, and I think he recommended 12 degrees. He will do a flat point pin, so that should help with weight. I also asked about a slot cut like a Lee slug, but he said it would most likely not cast well.

[hollow-point]

have you looked at cast bullet engineering 12g molds? he has a few designs and a paradox style H-P is one of them.

[megasupermagnum]

have you looked at cast bullet engineering 12g molds? he has a few designs and a paradox style H-P is one of them.

I had never heard of them before now. The one 730 grain mold looks about what I'm going for.

I am still waiting for the mold to be sent to Erik. I got my 5 cavity mold last week that I had ordered on the same day. I'm guessing it will still be another month or better before I get to cast the new slugs.

[MotelAlpha]

Looks okay to me though I think i'd go a hemispherical RNFP... but then I am thinking smoothbore. Things are a bit different for rifled gun.

As for the HB and skirt, I'm with BB on it likely being best to heat treat. I haven't run into a skirt yet that hasn't deformed some if not heat treated no matter how thick it was, and still looked like an HB slug anyway. I fill the cavities partly to support the skirt but mostly to keep wads out of the cavity. Heat treated or not if the slug has a hollow base wads will try to get in there, even nitro card wads. You could copy the Lee Drive Key or get a tapered hollow bored/reamed into the core pin like the Russian Paradox slugs so the skirt could be thinner but the wad would be stopped by the central pin.

I wouldn't go any thinner on the skirt than 0.100" ... at least without a pin or "key", but that's just me.

If you don't fill or use the key/pin idea then put a tough disk like polyethylene under the slug. That should keep wads out.

As for weight, you could lighten some by using just two driving bands and leave a wide, and deep as Tom can cut, groove. The old Paradox slugs had a huge groove! They were solid body so heavy even if they were HP'd but a hollow base design would lighten them a lot. I've always liked the Paradox design:

https://www.classicshooting.com/collections/holland-holland-sporting-cartridges/products/nitro-paradox-ammunition-for-paradox-guns?variant=1179491392

I'd stay away from too large a flat on top of the pin. I made mine fairly flat so keep lead in the nose but if I don't tip the mould a bit while pouring I often get a little cavity at the top due to air trapped over that big flat. Bubbles seem to flow off a radius or point but seem to hang onto the flat... at least in my mould. I think your radius looks good.

That slug would probably shoot just fine as is from rifled gun.

LongbowI had a Hollis 12ga SxS that was a Ball/Shot gun with very slight rifling that came cased and a slug mold exactly like that....it shot very well...680 grn slug 26 grns 4756.

[megasupermagnum]

I finally got the mold today, and couldn't be happier. Like anybody, I had the pot heating up before I even opened the box. I had the pot set at 750F, and it casts fantastic. I don't know why, but I always got well over half as rejects with the aluminum mold 73-770S. This new mold, once warm makes perfect slugs. They drop right off the pin no problem, and being as it is encased in a brass mold, it holds heat well. I only ran off a couple dozen, as the alloy was my mystery metal, just a mix of everything left over that I use for target ammo. It seems soft. I can't scratch my favorite 96/2/2 alloy with my finger nail, but I can with this metal. Weight comes out to be about 765 grains. They definitely have a weight forwardness, but I'm not sure if they will fly from a smooth bore. I will be sure to try though. The walls are thick, .150" at the base, so hopefully will resist hard cards trying to force into the cavity. The bearing surface is about .6", which should just barely bridge the forcing cone from hull to bore. The best I can measure, the forcing cone on my USH is about 1/2" long.

222050

222051

[bikerbeans]

Very nice! Now remove that HB pin and cast a real slug, probably 900 grains.:D

Hollow Points HB pin conversion is first rate.

BB

[Hogtamer]

That slug in 20 ga hb version is more my load these days. You guys are nuts, or soon will be shooting that monster! Those brass molds sure make pretty slugs, whatever size.

[megasupermagnum]

That slug in 20 ga hb version is more my load these days. You guys are nuts, or soon will be shooting that monster! Those brass molds sure make pretty slugs, whatever size.

The trick to heavy slugs, is a heavy gun. My USH is pushing 11 pounds. I agree, if I were to start completely over, I would have gone with 20 gauge. Estimated weight with a plain base is 943 grains with wheel weights. I want to try heat treating these, so it could be a few weeks before I try these out.

[megasupermagnum]

One thing I forgot to add is the two slugs I measured were .7358". I was hoping for .733", but that should fill the hull nicely.

[megasupermagnum]

I have been playing with these slugs for the past few weeks, with no luck. The three wad stacks I've used are x12x + (2) 1/4" felt wads+ (3) 1/8" nitro cards, the second is a x12x + (6) nitro cards, and the third x12x + 1/2" fiber + (3) nitro cards. I don't know why, but the felt wads cause terrible leading. Maybe they push up in the cavity of the slug? The best so far is the fiber wad. I've only used Blue dot powder so far. The slug is heat treated COWW, for a BHN 26, and one coat of Lee Alox. I may try pan lubing with a soft lube, but Alox seems to do the job well enough. Recovered wads look perfect, no indication of going into the hollow base. The problem is I can't get a decent group at all. After putting up a big sheet of paper, I found the slugs shoot high, but in a group 8"-12" at 50 yards. Usually things are going VERY wrong to get groups this big, yet the holes on paper are perfectly round. Absolutely no sign of wobbling or tumbling. It is worth noting that some other slugs I tried were not shooting very good, so it may be time to break out another slug gun just to rule out a problem with the ultra slug hunter. It was raining, and the berm at 100 yards was perfect for recovering bullets. I got a bunch in a good area, but only managed to recover one. I see no problems with it at all. The rifling looks clean, and centered, it is not engraving crooked. The hollow base looks perfect, no deformation at all. It is interesting that even heat treated, the nose got a big ding, probably from a rock. Even still, I just don't see how these slugs could be shooting as bad as they are. Maybe the big hollow base is just not conducive to good flight. I have been thinking of trying some as a solid slug, a full 940 grains. After casting them, I could flip them over and fill with lead. There would probably be more weight variation than the proper mold, but if my groups shrink down significantly, I know it's the balance.

Also, I ran some over the chronograph with 32 grains of Blue dot: 1050 fps

225820225821225822

[longbow]

Is that HB pin removable from the Cramer sliders? If so then a piece of round bar would likely replace it with minimal machining... or get Eric to send you a flat topped blank like Miha does. Then you can cast a real solid.

I'd try filling the cavity with hot melt glue before getting too carried away though.

If wads are pushing into the cavity they may be hanging on part way affecting flight or they may be distorting the base a bit... maybe not obvious but if the slug is say 0.002"/0.004" out of round you'd never see it but a 1:36" twist will make if wobble in flight.

I doubt filling with lead would work. First off the lead will not bond and it is a comical hole so the lead core would likely just fall out. Second, even if it stayed it would be difficult to cast a homogenous core of even weight so there again any off center void will affect flight.

I can't see any good reason that the slug wouldn't be shooting better than you are finding unless there is something "out of whack". Wads pushing into the base would be my first guess and filling the cavities with hot melt glue is easy and will stop that. If that doesn't improve groups then keep looking.

Also, I'd try a plastic gas seal then hard card wad column with nitro card on top. Felt and fiber are cushiony and may be crushing unevenly. Its another variable. I had terrible results with plastic wads and fiber wads under 0.735" RB's. Once I went to just plastic gas seal and all hard card wad column results were much better.

Its a good looking slug in a rifled barrel so I have to think you can get it to shoot.

Is it at least groove diameter? I've been assuming the slug fit is good and I'd figure at 0.735"+ it is filling the grooves.

MotelAlpha: Thanks for that info and load data. It may come in handy!

Longbow

[gpidaho]

You all know I'm pretty new to this but I wonder why you guys aren't powder coating your slugs if your getting leading? I've already tried it on round ball loads and it works just like it does on my rifle and pistol bullets, no leading. Gp

[megasupermagnum]

For the most part, leading is a non-issue. I even shot a different slug bare, as in no lube at all, and didn't see even the tiniest bit of leading until 50+ rounds. When leading is severe like I had in one case, something is very wrong. Once corrected, that slug shoots clean. Same with .735" round balls, it was not a problem for me. The velocities are so low, twists so slow, and wads to keep from any gas cutting, so there is no problem.

@longbow I did try an all nitro card stack, but it did not make a difference. I'll see about making a blank for the mold, the hollow base pin does look like it comes out.

[megasupermagnum]

Upon closer inspection, the base pin is actually held in by a roll pin, and it is not drilled all the way through. It looks a little small for me to want to try and force out. Maybe hot glue in the base is the best thing to start with, and see if it improves.

[Cap'n Morgan]

I have a hunch that maybe the muzzle blast is disturbing the slug when it leaves the muzzle. You could try using a faster powder or reducing the load to see if things improve.

[megasupermagnum]

I have a hunch that maybe the muzzle blast is disturbing the slug when it leaves the muzzle. You could try using a faster powder or reducing the load to see if things improve.

It's possible, but I'm not shooting these all that hard. I've kind of settled on 32 grains of blue dot for testing, and there is little muzzle blast. Very little flash either.

I just loaded some up with 30 grains, with an all hard card wad stack. I checked the gun over, couldn't find anything wrong. I will also try it without the fore end. I had cut grooves and filled with some lead, so who knows. Maybe something worked loose, and was causing weird pressure points on the barrel.

I'll also load some round ball with a load I know is accurate.

[longbow]

Have you checked slug weight for consistency?

I made a mould based on turbo1889's 10 ga. slug scaled to 12 ga. and I found that the near flat top on the HB pin would catch bubbles of air making for cavities on top or above the pin. Tilting the mould as I poured helped to minimize that.

Maybe you've got some cavities in the slugs?

Something has to be wrong if that slug doesn't shoot any better from a rifled barrel.

Yes, I'd try the hot melt glue. I fill my slug cavities to overflow then invert and press down on an oiled piece of steel to squeeze extra glue out and leave a flat base. Alternately you can over fill then use a utility knife to cut the excess to flat base. However you do it you want a nice flat base when your are done.

I have to think there is some issue to solve rather than the slug just won't shoot. Do you have another rifled gun to try it in?

Longbow

[longbow]

On second read. I note you are using 30 grs. of Blue Dot. Are you getting complete burning? I found that Blue Dot likes pressure or burn gets a bit erratic. Not sure just how much BD you should use with 765 gr. slug but if there is unburned powder in the bore you may need a bit more powder/pressure to get consistent burn.

[megasupermagnum]

On second read. I note you are using 30 grs. of Blue Dot. Are you getting complete burning? I found that Blue Dot likes pressure or burn gets a bit erratic. Not sure just how much BD you should use with 765 gr. slug but if there is unburned powder in the bore you may need a bit more powder/pressure to get consistent burn.

Absolutely, I will get these to shoot, I'm just reporting my observations good and bad. 30 grains is pretty mild, but the chronograph shows low velocity spreads. I just find 32 grains to kind of be the standard I use, no particular reason, but it performs well with a huge range of loads. When I figure out what is going on, I will go up in powder. Load data for 1 3/4 oz goes up as high as 40 grains, and 2 1/4 oz (in a 3 1/2" hull) shows a max about 38 grains. I've found Bluedot to work well over a huge range, but always seems to work better with a heavy payload. It seems to become much more consistent and predictable.

When shooting yesterday i had the perfect example. Those BPI value slugs, a 300 grain sabot, with 42 grains of bluedot throws a huge fireball, and is loud as can be. 32 grains behind a 765 grain slug was pleasant, no visible muzzle flash at all. A few weeks ago we had a problem with a fox eating chickens. One night before bed (maybe 1 am) I heard not one, but two calling very loudly outside. I had the shotgun, a 20" barrel mossberg 500 no less, and 32 grains of bluedot with 1 3/4 oz of #F. There was hardly any muzzle flash, and it was not even that loud either. I got one fox, never saw the other, but it never came back. I believe pressure helps it in cold weather, but I've had nothing but good results, even well below zero.

Yes I weighed all slugs, and hand sorted them with a careful eye. I too found a few with an air bubble on the flat top. These slugs are as best as I can produce, all weigh about plus or minus 2 grains. If my groups improve significantly with a filled base, I think that will tell me right there my problem. If not, I'll continue looking, one variable at a time. At this point I'm leaning more towards hunting with the .735" round ball. Those are good to at least 75 yards. This hollow base slug is just a project to see if I really can improve on the square shoulder slugs.

[longbow]

You'll get this beat. That is a good looking slug and no reason it shouldn't shoot well once you find what it and the gun like.

If velocity spread is low and consistent the powder must be burning well enough.

I like Blue Dot too. So far it is the best powder I've used for slugs at least with moderate to heavy loads. There are other powders I'd like to try but availability is an issue where I live... selection is poor.

At +/- 2 grains you've got no worries there either. I just figured I'd mention it just in case.

Filling the cavities is easy and if things improve it tells you something. If not well, there's got to be something happening that shouldn't be. Its all in the details.

Speaking of filling cavities... with that conical pin even hot melt glue may not stay in and it wouldn't do to have some plugs stay in and some not. I wonder if paraffin wax might be a better choice as it is likely to fall out.

This is when it would be nice to have slo-mo to check on these things in flight.

Keep at it and you'll win!

Longbow

[megasupermagnum]

I had been thinking about that, and I even tried filling a couple with lead. They fall right out. I have not tried hot glue yet, but I was thinking if I could just etch a few grooves inside, they would have something to hold onto. Maybe even just a couple turns on some sandpaper. I'll figure something out.

[Hogtamer]

The cheap hot glue guns with sticks from Walmart work fine. Overfill then trim with hot blade after they solidify. Make sure the last card is a hard card for a solid launch.

[gpidaho]

MSM: Here's a suggestion from the peanut gallery. If the lead isn't staying put in the cavity, could you tap in a screw as in attaching a tail wad and screw it in past flush with the base and pour lead around the anchor? Gp

[megasupermagnum]

I just filled the rest of my heat treated slugs with hot glue. It seems to have worked really well, no indication it will fall out at all. The weight of the slug only went up to about 771-772 grains, so very little change. I'll give them another coat of alox, and if nothing falls out from that jostling, they should be good to go.

[longbow]

I've had the hot melt glue come out of very tapered HB cavities. If the slugs are pre-warmed it should stick better and if you do the sand paper roughening trick that should help.

If you want to be really sure take gp's suggestion and drill and tap for a small wood screw then run it in past the bottom of the skirt. That's what I do with my Brenneke clones... except no skirt. I just leave the head sticking up a bit then slide the slug into the glue form and pour in the glue. The screw holds it very well. Only disadvantage... it's extra work!

[megasupermagnum]

I've had the hot melt glue come out of very tapered HB cavities. If the slugs are pre-warmed it should stick better and if you do the sand paper roughening trick that should help.

If you want to be really sure take gp's suggestion and drill and tap for a small wood screw then run it in past the bottom of the skirt. That's what I do with my Brenneke clones... except no skirt. I just leave the head sticking up a bit then slide the slug into the glue form and pour in the glue. The screw holds it very well. Only disadvantage... it's extra work!

No need. I even sacrificed one, and couldn't pull the glue out with a pliers! The good ones got coated in alox again, and loaded. Now just to make it to the range. This was my first time trying hot glue in a slug, it is surprisingly easy. Weights were consistent too.

[Hogtamer]

Works great in the Lyman slugs too.

[megasupermagnum]

I am going to cast more of these slugs this weekend, and am hoping for better luck this time around. I have been doing some research, and found lots of old posts by dixie slugs. One thing that stood out was his recommendation to fill the cavity with buffer, rather than hot glue. That's certainly something for me to try. Another thing is he used cork wads in addition to nitro cards. His claim was that felt, fiber, and other collapsible wads were not consistent, and would cause the slug to cant. He seemed to get very good accuracy with a stack of gas seal, 2 nitro cards, cork wads (did not specify amount), and one more nitro before the slug.

One other thing to note that I did not realize before. Look at the picture of the recovered slug on page 2. It is more obvious in person, but clearly that slug was skidding. Not like revolver hitting the forcing cone skidding either. It looks to me like the slug engraved, then somehow skipped in the bore and engraved a second time. At first I thought it was just scratches, but it is consistent all the way around. This is really odd to me, I can't even picture how it happened.