shotgun fullbore slug mold

[oldandslow]

Hi all, 12/2/11

I've had such good luck with Accuratemold's products in .45 and 9mm that I would like to order a fullbore slug mold for my Remington 870 12 gauge rifled barrel. My question is on the diameter of the slug mold. Do I order a mold that's .001-.002 inches larger than the slugged bore like with pistols or just order one that is the same size as the bore (alloy will be air cooled wheel weights with 2% tin)? I emailed Tom at Accuratemolds with the same question and he said it was best to run it by you folks here at CB. I tried the search function and didn't have much luck either. Thanks.

best wishes- oldandslow

[zac0419]

A member here "Dixie Slugs" has done a lot of things with slugs for shotguns. I'd shoot him a pm to chime in on this if when has time.

[white eagle]

I have an ACCURATE MOLDS slug mold

I do believe that I only went .001 over
reason being that is alot of lead coming out of a slug gun
I use an H&R USH nd I have more barrel side walls than most shotguns
slug your bore take a measurement then measure again
ask Tom his recommendation

[richhodg66]

Wow! What distance did you shoot that group at? Do these full diameter slugs require a roll crimp?

I'm going to start playing with the Lyman slugs for inside a wad, maybe I ought to just start with something like these instead.

[Blammer]

I would go .001 over your bore size. Any more and you'll need to run it through a sizer. Got one for your 12ga?

I have a 20ga full bore slug I had made and had it .001 over my bore size and it works beautifully! Do the "cake" lube or 'hand' lube thing and stuff them in the hull. They work great.

Fortunately with Tom you WILL get exactly what you order. So choose wisely!

my 20ga .626 dia 440gr slug.

[turbo1889]

James @ Dixie is the ultimate authority in the matter at hand but I do clearly remember him stating that his Terminator (heat treated) slugs are sized to 0.730" and are used in Hastings slug barrels that are 0.727" in the grooves.

Long story short I wouldn't suggest you go more then +0.003" with a hard cast lead slug. I personally have my 12ga. slug molds set up to cast at or about 0.730" since they are used in multiple guns with multiple bore dimensions and that particular size is best for a "catch all" size for a 12ga. slug mold if you don't want to have to size them. Which by the way if you do need to size them Buckshot can make a big Lee style push through die that screws into a press with the larger size 1-1/4x12 threads when you unscrew the bushing in the top of the press head. I tumble lube mine but you can also pan lube them.

If you know your barrel dimensions and want to order to fit your specific gun I suggest ordering at +0.001" and shooting them "as cast" which with the tolerances that Tom @ AM runs means it will be about +0.002" as cast since his tolerances are -0.0000" / +0.0015" and IME with ordering from him he almost always hits it at +0.001" in his stated tolerance range for the "as cast" boolit as it comes out of the mold or so which is just about perfect.

[white eagle]

Wow! What distance did you shoot that group at? Do these full diameter slugs require a roll crimp?

I'm going to start playing with the Lyman slugs for inside a wad, maybe I ought to just start with something like these instead.

That group was shot at 50 yards
yes a roll crimp is what I use and the crimper I have I had to modify
for the nose of the boolit but it was nathing

[oldandslow]

Thanks for all the advice gentlemen. I'm looking forward to another Accurate mold.

merry Christmas- oldandslow

[MikeS]

I would think that THE only proper way to load a full bore slug would be in a 2.5" brass shell with the boolit seated only half way into the shell, so it was more like a rifle cartridge than a shotgun shell. If I was going to do a full bore custom mould, I would have to have a design with a crimp groove in it as well! But then I would have to find a side by side 12ga with rifled barrels to shoot it out of too!

Now what I'm really curious of, if using a shotgun with a rifled barrel, doesn't that in effect make the gun into a rifle? I mean what makes it a shotgun if you're shooting a single full bore slug thru rifled barrel(s)? Having said that, is it legal to use a rifled barrel with a slug in areas that only allow shotgun hunting?

[Mk42gunner]

Having said that, is it legal to use a rifled barrel with a slug in areas that only allow shotgun hunting?

Mike, there were a lot of questions about that when rifled slug barrels like the Hastings and later factory fully rifled shotguns became available. Basically it boiled down to the fact that it was still a shotgun, and thus legal; unless the game laws stated smoothbore.

Robert

[turbo1889]

I would think that THE only proper way to load a full bore slug would be in a 2.5" brass shell with the boolit seated only half way into the shell, so it was more like a rifle cartridge than a shotgun shell. If I was going to do a full bore custom mould, I would have to have a design with a crimp groove in it as well! But then I would have to find a side by side 12ga with rifled barrels to shoot it out of too!

Now what I'm really curious of, if using a shotgun with a rifled barrel, doesn't that in effect make the gun into a rifle? I mean what makes it a shotgun if you're shooting a single full bore slug thru rifled barrel(s)? Having said that, is it legal to use a rifled barrel with a slug in areas that only allow shotgun hunting?

Mike, there were a lot of questions about that when rifled slug barrels like the Hastings and later factory fully rifled shotguns became available. Basically it boiled down to the fact that it was still a shotgun, and thus legal; unless the game laws stated smoothbore.

Robert

Allow me to expand further on the questions and issues that MikeS has brought up:

First of all one must understand the original "Why" of the shotgun only rule for certain hunting areas. It revolves around a safety concern regarding the lethal down range capabilities of stray bullets potentially exiting the hunting area. Long story short, at least originally beyond about 450 yards a shotgun slug was no longer a potential danger due to the fact that it has a ballistic coefficient roughly equivalent to a flying brick and although extremely effective and deadly up close bleeds off energy over range like a bucket with a hole in the bottom and has an extremely curved rainbow like flight path with an incredible amount of drop at longer ranges.

A good example for comparison purposes is a 12ga. foster slug vs. a 30-06:

A classic slug load for the 12ga. is a full bore diameter 1-oz. foster slug load at a muzzle velocity of 1,600-fps totaling roughly 2,550 foot pounds of energy at the muzzle. However such a slug has a ballistic coefficient of roughly 0.07 which means that at 450 yards down range it only has about 270 foot pounds of energy left with a drop of about 38 feet. Which means that unless you are angling the barrel way up or shooting from the top of a hill the slug buries itself in the dirt long before it ever gets out that far and even if it does get out that far it only has about 270 foot pounds of energy left and thus its ability to deliver lethal force is almost gone.

Where as a 150gr. soft nose spitzer 30-06 deer hunting load with a muzzle velocity of 2,900-fps which totals roughly 2,800 foot pounds of energy at the muzzle has a much higher ballistic coefficient of approximately 0.3 which means that at 450 yards down range it only has a drop of about five feet and still has over 900 foot pounds of energy left and is still very much a lethal threat and is more likely still airborne due to considerably less drop.

Now enter the rifled slug barrel for shotguns ~ in and of itself having rifling in the barrel doesn’t change the drop or the energy loss of the slug over range. All it does is give the hunter better accuracy capabilities thus, at least originally, the rifled slug barrel for shotguns did not change to root fundamental physics behind the reason why shotgun slugs provided a safety advantage over high powered rifles in some hunting areas and so long as full bore slugs with their “flying brick” ballistics were used the slug would still only carry so far and was not a potential safety risk over extended range. Thus, it was determined and now is held pretty much in common practice and common law precedent in the U.S. that provided the rifled slug barrel is still chambered to accept a standard shot shell and any other shot shell can be safely chambered and fired in such a rifled slug barrel (although obviously the resulting shot pattern isn’t anything to brag about) the gun is still legally a shotgun and is not subject to the “Destructive Device” provision of the ATF or special exception in hunting regulations as not being a shotgun unless they specifically prohibit a rifled barrel.

Now enter the sabot slug for use in rifled slug barrels ~ this is where the game started to change and more streamlined smaller diameter projectiles with better ballistic coefficients launched a higher muzzle velocities through the use of a plastic sabot could carry further with more retained energy and less drop. Thus today there are some hunting areas that not only specify shotgun only but also prohibit sabot slugs and require full bore slugs or buck-shot be used and sabot slugs are not permitted. An example of this is several sections of state trust land up here in Montana that although the Fish & Game has not made any prohibition of the use of sabot slugs the state land trust office which manages those land tracts has specified that high velocity sabot slugs and sabots for muzzle loaders are not permitted for use by hunters in several sections of state trust land which they are in charge of managing that are smaller size and present a greater safety risk of any loose projectiles exiting the hunting area and striking in surrounding populated areas. A group of hunters who load our own including myself were able to petition the office in regard to the rule and got an exception added for “Wad-Slugs” that being slugs like the Lee and Lyman slugs that although aren’t true full bore diameter slugs use a conventional thin wall shot wad for a sabot and unlike true high velocity sabot loads still exhibit the “flying brick” behavior of full bore diameter slugs down range due to the slug being only slightly smaller then full bore diameter and thus are in the same class as full bore slugs as far as the safety concern of the slugs ability to deliver lethal energy over extended range.

In conclusion, big heavy full bore diameter slugs with their “flying brick” ballistics that make them extremely potent up close but also mean that they are represent much less of a risk as a loose projectile down range are not a problem in fact they are more in line with the original intent of the law then the factory sabot slug loads that are so popular today.







Now as far as full length brass cases go. For most peoples needs conventional plastic shotgun hulls are actually the better choice. The reason for that is the fact that in order for the gun to be legally considered a shotgun the chamber must accept standard shot shells as well. If it does not then the guns legal classification as a shotgun becomes ambiguous and potentially subject to challenge. If the wall thickness of both plastic shotgun shell hulls and brass cases was the same then that wouldn’t be a problem, but that is not the case at all.

The wall thickness of plastic shot shells is about 0.03+” or so where as straight walled brass cases (such as a handgun uses) are about 0.010” to 0.015” thick at the mouth were the bullet is seated. Thus if “normal” thickness brass is used to make the brass case (such as is done with MagTech brass shotgun shells) and the case mouth is sized to give proper neck tension on the slug which is seated and crimped in the case mouth like a conventional metallic cartridge and the chamber is cut to dimensions to accept conventional plastic shotgun hulls your brass case slug shell will be 0.03” to 0.04” smaller diameter then the chamber which is unacceptably loose and can cause accuracy problems as well as premature case failure due to being overworked when it is blown out to the larger chamber diameter and then sized back down so much for every reload cycle. If you cut the chamber smaller diameter then you have a potential legal problem. Now it is possible to use very heavy wall thickness brass cases that have the same wall thickness as conventional plastic shotgun shells which are two to three times thicker then normal brass thickness and that has been done and done successfully. The problem with doing that becomes a matter of cost (go check out the price list of rocky mountain cartridges which is the main supplier of such cases and you will get sticker shock) and a matter of working with the much thicker and heavier walled cases in the loading process. Believe me a crimp groove would be worthless you are not roll crimping 0.03+” thick brass case walls like you normally do with the regular thickness brass cases on your revolver rounds all you get is a light taper crimp just like used on a 45-ACP or other auto loading non-rimmed handgun round that head spaces on the mouth of the cartridge. It’s not really a crimp at all but just taking the belling out of the case mouth that allowed you to seat the slug and it is a neck tension only affair and believe me there is plenty of neck tension and you have to be sure that you only have about 0.001” of neck tension in the internal diameter of the case mouth before seating the slug otherwise with those big thick case walls it will just squeeze down the diameter of your slug. You also need great big custom made dies that thread into a 1-1/4” or 1-1/2” press head and a massive very strong press to put them in, a lot of guys use the big Corbin swaging presses.

[excess650]

I have a NEI that drops a .735" "collar button" that weighs in excess of 600gr. I've cast them 25-1, panlubed 'em and shot 'em from my rifled 870. The recoil was robust enough to cause the rear sight to climb up its ramp! As much as I would like to pursue 'casting for shotguns" with my 12ga, the recoil gives me a headache.

My 870 liked Fedral Permium and Lightfield sabots (2-3/4") despite its 3" chamber. It would keep 5 shots inside 3" at 100 yards with the barrel sights (10 years ago). I also have a Browning A-bolt Hunter, fully rifled, and it liked the same 2 loads. It was scoped and would keep its shots sub 2" at 100 yards.

Yeah, I agree, they are .73 cal rifles, but legal as "shotguns" where I hunted in Pa and NY.

[tommygirlMT]

excess650 --- your excess recoil problems (pun intended) are due to felt recoil being a function of the impulse curve --- use a larger amount of slower powder --- IMR4759 IMR4227 Reloader17 --- and you will get as much or more muzzle velocity with less smack on your end --- feels like a long hard push rather then smack you silly --- especially with Reloader17

[excess650]

excess650 --- your excess recoil problems (pun intended) are due to felt recoil being a function of the impulse curve --- use a larger amount of slower powder --- IMR4759 IMR4227 Reloader17 --- and you will get as much or more muzzle velocity with less smack on your end --- feels like a long hard push rather then smack you silly --- especially with Reloader17

There's a thought! I was using Blue Dot and roughly interpolating 1-3/8 or 1-1/2 oz shot data.

[tommygirlMT]

Very few powders much slower then BD burn right at low pressure --- the three I listed are known to be ones that do

Use a MAGNUM PRIMER in a 3 inch length 12 bore hull --- Fed-209-A is a really good choice --- the primer that comes in the Federal 3.5 length 12 bore hulls when you buy them as "new primed hulls" is even better (you can trim them down to 3 length) --- then put in the powder charge:

IMR4759 --- 65 to 80 grains
IMR4227 --- 70 to 85 grains
Reloader17 --- 100 to 130 grains

Then you put in a plastic gas seal over the powder --- the "Power Cup" gas seal from BPI is really good or you can take a plastic shot wad and cut the very bottom gas seal part off the bottom of it and use that --- then you put in at least two nitro cards that are an eighth of an inch thick for at least a quarter of an inch worth of nitro cards --- you can put more then that if you need to for adjusting height of wad under slug to get it to sit right for crimping --- then you use the ram of your loading machine to compress the living hell out of the wad column and powder charge --- like a hundred or more pounds of wad pressure --- then you put in the slug quick and roll crimp it nice and tight --- dont do up a whole bunch except for the roll crimp and then roll crimp them all --- you want to roll crimp them shortly after applying all that compression --- those powders burn more consistently and ignite better if you compress the living hell out of them and trap that compression by capping them off with roll crimp shortly there after

Now --- random notes ---

I did say IMR4759 not IMR4756 --- they are not the same do not confuse the 9 and the 6

This is for 12 bore 3 length shells with slugs that weight between 600 and 750 grains or so --- heavier then that you have to back off the charges a little --- lighter then that and you dont have enough weight to get good burn and not get vertical stringing

Yes you really have to use that much powder --- dont use less then what I listed --- dont use more --- you need at least two nitro cards for cushioning --- dont use in old antique or damascus barrels --- modern guns only

COMPRESS THE POWDER --- use a bunch of wad pressure and cap it off shortly after with roll crimp --- this is a compressed load (think compressed loads with the little "c" next to them in metallic load books) --- the compression makes the loads better

[kaytod]

I ended up with a copy of this from somewhere. I do not know where. However the credit is due the original author and the workmen that assembled the report.

If the moderators find this to be problematic, please delete this as I do not want anyone to be at issue with this posting. Merely to inform
Thanks

{I was wondering around the net and found this article. Thought it was interesting even though I don't live in a shotgun only state. I use a slug gun by choice. Some of you may have already seen it. I went ahead and copied and pasted because allot of times these things get taken down after a certain period of time.}original author unknown.

The link is found here:
"http://findarticles.com/p/articles/mi_m0BQY/is_11_53/ai_n20512665"


The text is as follows:
The "safe" slug myth: shotgun slugs are required in some areas, but why?
by Holt Bodinson

The shotgun slug is less safe and more dangerous in the field than a 150 grain .30-06 bullet
or a 50-caliber muzzleloading projectile. Does that statement sound improbable?
Conventional wisdom would say so.

I've just finished digesting a 67-page technical report commissioned by the Pennsylvania
Legislative Budget and Finance Committee that blows a hole in conventional wisdom and the
increasing establishment of shotgun-slug-only zones by state's game agencies.

What prompted the study? A lawsuit involving a hunting accident in which a woman sitting in
a car was struck by a stray rifle bullet coupled with increasing sportsmen's opposition to
the expansion of shotgun slug and muzzleloading-only zones on the decision of the Pennsylvania
Game Commission.

When the professional staff of the Game Commission questioned other states with about their
slug policies, they found no state had any definitive safety data to support the decision
to restrict zones to shotgun slugs. Quoting from the report, "They found in the shotgun-only
states, this appears to be an issue driven by emotion and politics rather than sound scientific
data."

The Army Weighs In
The research firm, Mountaintop Technologies, conducted the resulting outside-contracted
study. Its prime subcontractor was the US Army Armament Research, Development and
Engineering Center at the Picatinny Arsenal.


The Picatinny research team used the concept of Surface Danger Zones to compare the
relative risk performance of three projectiles: a 150-grain SP fired from a .30-06 with a
muzzle velocity of 2,910 fps, a 385-grain, 12-gauge, 50-caliber sabot load with a hollowpoint,
semi-spitzer projectile at 1,900 fps and, for the muzzleloaders, a 348-grain, 50-caliber CVA
Powerbelt projectile at 1,595 fps.

The March 2007 study looked at the maximum range a projectile would reach at various firing
angles of elevation plus the distance the projectile would ricochet after impacting the ground.
The data is intriguing.

At a maximum firing angle of elevation of 35-degrees, the rifle, shotgun and muzzleloader
projectiles travel 13,926', 10,378', and 9,197' respectfully. Because of the angle of descent,
there are no ricochets.

At a firing angle of 10-degrees, the rifle, shotgun and muzzleloader projectiles travel 10,004',
7,163' and 6,247' respectfully plus additional ricochet distances of 702', 949' and 913'
respectfully.

Ah, but the big surprise comes at 0-degrees of elevation which would be more or less a typical
shot at a deer on level terrain. Here the rifle, shotgun and muzzleloader projectiles travel
1,408', 840', and 686' respectfully plus ricochet distances of 3,427', 4,365', and 3,812'
respectfully. Now the total distances traveled by the projectiles are 4,835' for the rifle,
5,205' for the shotgun and 4,498' for the muzzleloader.

"The smaller cross sectional area of the .30-caliber projectile and its shape contributes
to a higher loss of energy on impact and, after ricochet, the 30-caliber projectile tends
to tumble in flight with a high drag. Test data confirm that the 50-caliber projectile's
larger cross sectional area and its shape contribute to less energy loss on shallow angles
of impact and, after ricochet, the projectile exhibits less drag which results in a greater
total distance traveled.


"It is recommended the Pennsylvania Game Commission address the public perception a shotgun
with modern high-velocity ammunition is less risky than centerfire rifles in all
circumstances ... Frangible, or reduced ricochet, projectiles for hunting firearms should
be investigated as an alternative to the mandatory use of shotguns or muzzleloaders."

Far Reaching

I think the effect of this study may be far reaching and it's why I have covered it in such
detail. State game agencies tend to talk to one another and, indeed, tend to copy each
other's regulations. It will be interesting to see what impact this study may have on
present or future slug-only zones and on shotgun slug design itself.

The answer may be in making the shotgun slug more frangible. Slug design is increasingly
taking on the structure and composition of a jacketed bullet. Looking at the design of the
new xp3 Winchester, the Hornady SST, and Federal Fusion slugs, it's clear we are already
there. They're built like jacketed bullets, and they upset and expand like jacketed bullets
. They're the finest rifled shotgun slugs we've ever had plus muzzle velocities keep
increasing with every passing year.

I'm sure the major ammunition companies are studying this groundbreaking report from
Pennsylvania with keen interest. Knowing them as I do, they will have a solution to slug
ricochet problem within months so stay tuned.

[turbo1889]

The above quoted report is about a sabot slug. Not a full bore slug, as I previously mentioned in my previous post the sabot slug is a whole different animal then the full bore slug.

Yes, ricochet distances can be a problem for any projectile but a "flying brick" full bore slug is a "tumbling flying brick" in ricochet and still bleads off energy at an incredible rate over even moderately extended range.

Although I have never done any laboratory type testing I do have one an area to shoot where I have an almost unlimited range of dry dusty land where you can lob slugs out there and "skip bounce" them across the ground like skipping stones on a lake and you can see any impact with enough energy to be worth anything due to the clouds of dust created. Long story short full bore slugs even when skipped along the ground from a fairly level shot still don't go very far. As I said "flying brick" even if you skip it a couple times you can still only throw a brick so far. The one possible exception is a good hard round ball; they do skip pretty good and don't bleed of energy nearly as fast especially once they drop into the sub-sonic velocity range.