New Mold on the way

[bikerbeans]

I like the meplat on this one, should make roll crimping very easy. 3 week delivery for the cost of a lyman pellet mold. This is a solid base slug for a 12ga rifled barrel. Accurate will make nose pour slug molds but you have to outsource the base pin.

Lost the dimensions! Band diameter is 0.732" +0.002" and 680 grains with hardball alloy.

BB

[longbow]

Looks good!

What is groove diameter? Are you going shoot as cast? Sized to size to groove? Over groove? a little under groove? I'm curious because some slugs seem to be sized a little under groove diameter and the old Kynoch Paradox slugs were apparently sized to slip fit to the smoothbore bore section at about 0.001" less than bore diameter. Ross Seyfried reported that he had tried sizing to 0.001" over bore unsuccessfully then found a "regulator" that sized the big boolit to slightly under smoothbore (groove) diameter and that worked! Interesting article.

Anyway, just curious what you and others are doing there.

I'm sure that slug will leave a mark at both ends when fired! What load data are you using?

Accurate makes a nice mould for sure. I only have one so far and it is a beauty so I'm sure you will be happy with yours.

Longbow

[6pt-sika]

That ones a skoosh heavier then the Russian knockoff of the 10 gauge version of the Lyman Sabot mold I have . And of course a good bit less in diameter since I can load it in the SP-10 wad with the petals intact . If my memory serves it weighs 620-630 grains .

[bikerbeans]

LB,

Assuming the slug drops at 0.732" band diameter I will just lube and launch them. I need to measure the groove on my 512, but it shoots well with 0.732" FB slugs. That diameter slug fits tight in the hull so i think that helps accuracy.

This slug is identical to a 700 grain accurate slug a friend cast me, but with a shorter/wider nose. I think the wide nose profile helps a lot on roll crimping. I plan to use SR 4759 and expect a charge in the 60g range should work.

BB

[Taylor]

Just bought a new mould from Accurate myself. 73-570S.

[megasupermagnum]

I've been thinking about getting another slug mold myself. I've been playing with the 73-770S, but never got any great accuracy, nothing that beats out the .735" round ball. I did figure out a lot of things. The first is that with a bullet this big, it doesn't leave much material to hold heat. I bought mine in aluminum, and it can be a little challenging to keep it in the sweet zone while casting. My next one will be brass. Next, I had problems with lube. I was pan lubing with Canaruba Red, but it was a royal PITA. The big problem was that it would not come off the slug once I left the barrel. Every slug I recovered had quite a bit of lube still in the groove, often only on one side. I think this is why I was getting oblong holes in paper. I also played with wad columns. I started with petals cut off a 12S4, with some hard cards. I later found a gas seal, hard card, and fiber wad to be the way to go. One thing I found is if you pan lube, the wad can stick to the slug base. I tried using an overshot card between the slug and wad, but they just stick to the slug themselves. I think a hard card under the slug might help.

I've always felt the biggest disadvantage a slug gun has, is that it has to have a forcing cone, rather than a proper bullet throat. Because of this, I've been trying to think of a slug design to maximize self-centering. I would have to think a big RNFP to be the answer, and keep the slug long enough so that the base is still in the hull, while the nose is hitting the rifling. Because of this, a solid slug would just be a boat anchor. I think a hollow base is the way to go, and about 600 grains would be ideal. I've got too much stuff going on right now, but I hope to have Accurate molds make this slug mold in the future.

Also, I think that 73-680C meplat is much better than the tiny one on my 73-770S. If you are going to shoot a big slug, don't waste its terminal effects.

[bikerbeans]

The 73-680C is essentially the 73-700S with a shorter nose. A friend of mine has the 73-700S mold and sent me a 100 bullets several years ago. I have only shot about 20 of them but results are very good to 50 yards. I plan to test them at 100 yards this week. I decided to buy the 73-680C mold because of the wide nose really helps with the roll crimp.

I tumble lube FB slugs with 75% JPW & 25% LLA. This lube drys an isn't sticky and recovered slugs are lube free.

The lead and mold need to be HOT to cast large slugs. With a HB pin heat is a bigger deal. Getting a quick slug release from the base pin is one of the reasons I am switching to a solid base design.

Turbo sold a HB FB 12ga slug that weighed about 575 grains. The heat treated version of this slug is a very accurate slug. I still have a few of these slugs and have considered using them for a pattern for a new mold. Downside is $200 to $300 for a mold, compared to $80 for a new solid base mold.

BB

[bikerbeans]

The forcing cones on the rifled slug guns I have measured are very long so it would take at least a 1" long slug to be in the rifling and the hull at the same time. Bullet jump in a slug gun is a fact of life for anything but an attached wad slug or a very heavy slug. I found that just like shooting cast bullets in a rifle you want as large a diameter slug that will chamber in your RIFLED shotgun. This will help center the slug with the bore. This advice may not apply to smoothbore slugs loading.

BB

[jmort]

Very interested to hear how this works
I am going to have Tom cut a mold for me that is forward heavy and longer
Use a long wad and a seal
Right now it is the 1000/1000 based on weight and intended velocity, sub-sonic
Will probably reverse engineer it to fit an off the shelf wad

[longbow]

BB:

Would you please post pics of that turbo slug? Side view and open base?

I was sure he'd posted a drawing of at least one of his successful 12 ga. slugs but I haven't found it. The only drawings I've found are of the Lyman sabot slug and his 10 ga. design. The 10 ga. design is the one I scaled down to 12 ga. and made a smooth sided mould of. That one is shooting not badly for a Foster. It is also the one I've put Russian tail wads on to test... they fit perfectly!

Anyway, I'd like to see the slug you have if its not too much trouble.

The mould I made casts exactly 0.729" with wheelweights and it weighs 565 grs. It has a fairly deep HB cavity so longish body with good bearing surface. I can send you some if you want to try them. I knurl them up to over 0.734" then size back to 0.733". There's not much knurl left to hold lube after but not a problem in my smoothbore. If you want some to try, let me know.

Longbow

[megasupermagnum]

The 73-680C is essentially the 73-700S with a shorter nose. A friend of mine has the 73-700S mold and sent me a 100 bullets several years ago. I have only shot about 20 of them but results are very good to 50 yards. I plan to test them at 100 yards this week. I decided to buy the 73-680C mold because of the wide nose really helps with the roll crimp.

I tumble lube FB slugs with 75% JPW & 25% LLA. This lube drys an isn't sticky and recovered slugs are lube free.

The lead and mold need to be HOT to cast large slugs. With a HB pin heat is a bigger deal. Getting a quick slug release from the base pin is one of the reasons I am switching to a solid base design.

Turbo sold a HB FB 12ga slug that weighed about 575 grains. The heat treated version of this slug is a very accurate slug. I still have a few of these slugs and have considered using them for a pattern for a new mold. Downside is $200 to $300 for a mold, compared to $80 for a new solid base mold.

BB

I hadn't even thought of tumble lube, that may be the way to go. With my 73-770S, I can manage 2" groups at 50 yards, but 100 yard groups barely stay on target. About how round balls shoot. I've found the best way to cast the big slugs with this mold is to pre-heat it on a hot plate. There's no way I can cast fast enough to get it warm without it. I can barely keep pace with it when it's warm. I don't think a 1" long slug is unreasonable, especially a hollow base. I do have a few more Ideas for the 73-770S, but I don't have high hopes for 100 yard groups.

[bikerbeans]

Mega,

What is the twist rate of your barrel and muzzle velocity of your load? Maybe a transonic zone transition problem? If your load punches round holes at 50 yards then I don't think you have a stability issue.

BB

[longbow]

You know what might work well for lube and is easy? I use what I call hot tumble lube. I came up with a variation (kinda) of Felix lube using Paraffin wax, Lucas Red 'N Tacky grease, Ivory soap and Bardahl oil treatment. I developed right about when Ben came up with Ben's Red... quite coincidental. My first batch was a bit hard but very slick so I decided to melt some in a frying pan then roll boolits around in it. Worked like a charm so that is how I've been lubing lately. No drying time required other than waiting for boolits to cool off.

I'm sure the "hot tumble lube" method would work with about any beeswax or paraffin based lube that you can melt without scorching. Just put those big 'ol slugs into the frying pan with just a bit of melted lube and let them warm up a bit then roll them around to coat them. Goes on much like LLA but no drying time. I've had no leading and good accuracy in .303 British and .44 mag doing this.

I haven't had leading issues so far with shotgun slugs but if I lube this is the method I'll use.

As for stability, I haven't worked it out but with a 770 gr. slug I wonder if length/twist is the issue. I found that my Marlin 1894 with 1:38" twist would not stabilize any boolits I tried over 280 grs. I tried 300 gr. boolits and they would shoot pretty well at 50 yards but keyholed at 100 yards. Keep weight under 270 grs. and all is well to 200 yards.

Longbow

[bikerbeans]

LB,

I ran numbers on the 770g slug in the JBM ballastic calculator using 1:35 twist. Result was a stable slug at any supersonic velocity. I did notice if the MV was 1,300 fps or less then the slug would enter the transonic zone before it traveled 100 yards. Maybe this is why the heavy old buckhammers had a 1,500 fps MV? The buckhammer was accurate to well past 100 yards.

BB

[SuperBlazingSabots]

[bikerbeans]

Ajay,

Nice CAD work. The HP mold would drive me crazy, I have enough trouble casting with a base pin mold.

BB

[longbow]

BB:

Yeah, I have to wonder if many of the slug designs do become unstable at transonic velocity. turbo maintained that the Lyman sabot slug did when shot from smoothbore. If true then that should apply to many wadcutter style HB slugs. Shouldn't be a big issue if at all from rifled gun but a little long range testing would tell the story.

Ajay:

That looks a lot like the old Dixie Tusker but longer nose and maybe a little deeper HB. The Tusker, which other than the old Kynoch Paradox slugs, is my favourite... okay they're even! I like both designs a lot. If I ever get a rifled gun... I'll get both Tusker and Kynoch designs. In fact I am surprised that no-one here seems to be shooting the old Kynock Paradox design slug. CBE makes moulds.

James posted the drawing for the Tusker which I think is an excellent design but again, no-one seems to have gotten a mould made... or at least isn't posting about it if they did. It was a nice weight at 600 grs. too, heavier than most factory slugs and commercial slugs but not too heavy.

I like the Tusker better than the above design but that's just my opinion.

Longbow

[Grmps]

The hardest part isn't waiting for the mold, the hardest part is after you get the mold and have to go through the seasoning process

[megasupermagnum]

LB,

I ran numbers on the 770g slug in the JBM ballastic calculator using 1:35 twist. Result was a stable slug at any supersonic velocity. I did notice if the MV was 1,300 fps or less then the slug would enter the transonic zone before it traveled 100 yards. Maybe this is why the heavy old buckhammers had a 1,500 fps MV? The buckhammer was accurate to well past 100 yards.

BB

I'm shooting them from an Ultra slug hunter 1:35" twist. I don't think stability is the proper word, the slug is only as long as it is wide. It can't take much to spin stabilize. I think there is more to it than that, and it's common across many, many shotgun slugs. With blue dot, I've ran them up to 1,150 fps, but I feel based on velocity, and a deep extractor dent, that the pressures must be up there. I feel 1000-1100 fps is about what you get out of these. You might be able to get a little more out of STEEL, but any more and you have to go into Ed Hubel territory. I've been thinking of trying 100 grains of Reloader 17, which I'm told will push them around 1500 fps, with safe-for-most shotgun pressures. Back to the stability thing, something has to be very wrong to not get decent accuracy at 50 yards, yet, it's rather rare to find a slug that will consistently group at 100. By that I mean sub 4" CTC. Smooth bores are the worst offenders. Nearly anything will be sub 3" at 50, yet you are lucky to be under a 12" group at 100. A lot of that can be attributed to going subsonic, but in the case of a slug that starts at 1000 fps? I have no real idea what's actually going on, it's just a WAG. At one time I tried nearly all the factory sabot rounds, in multiple guns, and yet every muzzle loader I had access to would shoot better. The best was the USH I have now, with Hornady SST slugs (the new LOTS shoot horrible) and it was as as close to a sub 2" 100 yard slug gun I've seen. My current muzzle loader, straight out of the box, shoots every single bullet I ever tried under 3" at 100 yards.

I have to think its the forcing cone holding slug guns back. What else could it be?

[bikerbeans]

With your USH you could ream it to 3.5" and eliminate a 1/2 inch of forcing cone. Obviously a reamer that cuts a short throat would be needed. IIRC, someone on the forum has a reamer like this and cut a 3.5" chamber on their USH. I can't remember who it was and searching with my tablet is a diaster.

My marlin 512 has a long forcing cone but it would shoot buckhammers 2 moa or better at 100 yards. I had a rifled autoloader 10 years ago that was just as accurate with the buckhammers. I think a long forcing cone isn't a fatal flaw on a rifled slug gun, you just need the right load. Problem with slug loading compared to CF rifle is more components equals more variables and more chances for error.

BB