Lyman foster mold

[finstr]

I purchased a Lyman 12 ga mold from my lgs. I ordered it online from a used section of their site. I assumed that it is a sabot slug mold because I wasn't aware that Lyman had even made a foster slug mold. Then I started reading a bit here about the Lyman foster slug molds and how they are a problem because of their as cast diameter.
This mold I purchased didn't have any part numbers or specs listed but it was cheap enough to gamble with.
In the event that it is in fact a foster slug mold, what is the possibility of taking a Lee sizing die that I have no use for and reaming the hole out to the correct diameter to swage the foster slugs down to fit in a shot cup?
Have any of you attempted that?
Thanks

[bikerbeans]

finstr,

I have push thur sizers in 0.722" and 0.729". I size full bore slugs that have 3 driving bands and if the alloy is hard it is a PIA. Slugs cast from 30:1 alloy are easy to size. With a HB slug you need a punch to match the HB cavity or you will probably deform the sidewalls. Also, I think if the slug is flat sided pushing a slug thur will be more difficult, especially with harder alloys. The most I can size in one pass is 0.01" and that is with 30:1 pb/SN alloy.

BB

[RogerDat]

Might want to look into a push through sizer and send them through hollow base first, with ram pushing on the nose at the sprue cut point. Little fiddly to get bullets such as HBWC's in and lined up that way but not too bad and I would expect the volume of 12 gauge slug would not be super high. Lee makes the dies to your dimension but not past the .575 on their site, still it might be worth a call, the cost isn't too bad.

NOE molds makes push through sizers, they list through .50 caliber but are another outfit that might make you a push through die of proper size. In any event I think flat or nose matching would be easier to come up with than base fitting. Base first would be where I would be looking.

[finstr]

Ok thanks guys. I've just heard back and the mold indeed is the round nosed type foster slug. I assume I will have to cast some slugs first and see what they drop at for diameter.
My understanding is that some fellas are getting about a .710 dia using this mold. I could possibly swage them to .690 to reduce the diameter to fit in a thin wall cup or perhaps powdercoat them after knurling or fattening them to fit the .729 full bore.
Anyway I will cast these using pure lead stick on WW type alloy so they're malleable enough to work with.
I really would like to shoot these thru my rifled Hastings barrel and kill some deer with them.
Our big bucks tip the scales at 300+ so a decent slug has to penetrate a fair bit of meat..

[longbow]

Mine casts at 0.705" so pretty small but better if a guy plans to size down.

I have not tried sizing mine down but was considering having driving bands machined into the mould to increase diameter to bore size. I suspect that would cost as much as a new mould though and would likely be no better than a Lee 1 oz. slug in the end so I didn't bother.

I do kinda like the wad slugs though so sizing down is the way I'd go.

I tried sizing Lee slugs to remove all the taper but cast from ACWW they wouldn't take the sizing and broke up. That was about 0.020" reduction. I opened the sizer up to 0.675" IIRC which takes most of the taper out and that worked so about 0.010" reduction. Soft lead would go easier. If you could size to 0.685" you'd likely be good. You might find shotcups that will take a 0.690" slug. If so it would be easier sizing.

If cast from soft lead the Lyman Foster will slug up and fill the bore but mine did it very unevenly and accuracy was poor. Slugs recovered from deep snow told the tale! A good solid wad column is your friend there.

Good luck in your endeavour.

Longbow

[finstr]

Thanks longbow this could be an exercise in frustration maybe lol. Nothing ventured nothing gained I suppose.

[longbow]

If you got it cheap it can't hurt to try.

My main complaints of the Lyman Foster slug (and mould):

- casts too large for shotcup
- casts too small for bore
- has a thin nose and skirt so tends to flatten out easily at impact... no personal experience but I've been told they turn into big lead washers when they hit deer, if cast out of pure lead, so poor penetration
- my mould is not easy to cast with; mostly the core pin sticks badly though mould release and/or polishing may fix that
- thin skirt = large cavity into which wads will go if the cavity is not filled or a very solid base is put under the slug ~ beyond nitro card wads in my experience

I believe that the Lyman slug casts small because Lyman/Ideal used to sell a rifling swage kit and I am betting that swaging grooves into the slug also raised lands about the same amount bring size close to bore. Those rifling swages have not been available for many years but the slug mould has not changed in diameter.

In my opinion a good modification to the mould would be to shorten the HB pin to make a thicker nose and add a tapered slot to produce a "key" like the Lee Drive Key slug, and machine bore diameter driving bands into the mould but... unless you can do it yourself, not likely worth the cost. You can buy a Lyman sabot slug mould cheaper.

Just one man's opinion.

Longbow

[finstr]

Look what showed up in the mail!
So I cast some and once the mold heated up it was working good. These are pretty consistent for weight at 477gr.
They measure .702”
These are as close to pure lead as I can get and set them on shop rag instead of water dropped to preserve the softness.

I measured some factory sabot slugs w sabot attached;
Win partition gold .725"
Win BRI .745"
Lightfield hybrid ..732"

Kind of interesting that the rifled bore of the Hastings is ..725"

Also I measured a Win AA foster slug at .703" hmm....

[bikerbeans]

Lookin' good. The trick will be finding a wad column that will bump up those slugs without tilting them.

BB

[longbow]

One of the old guys here told me to use a copper washer on top of a hard card wad column under the Lyman Foster so that it would bump up evenly and he swore it worked but I tried it and no go for me. That slug has given consistently bad accuracy for me except when paper patched to bore diameter which worked fairly well.

However, it is worth giving them a try and seeing what results you get.

I recommend filling the cavity to keep wads out though that may inhibit slugging up to fill the bore. A bit of a dilemma! Maybe a disc of polyethylene on top of nitro card wads would help (or the copper washer). That saved my when using my 6 finned slugs that at nitro card wads! I used an old Magic Carpet snow slider and punched 3/4" discs out of it. That worked well under those slugs but I never tried it under the Lymans.

Good luck!

Longbow

[finstr]

Thanks LB, all good tips!
I have ordered Lyman's shotshell loading manual from Amazon and should be here in a couple days. Hope to get some trials going.
Although I'm definitely not new to loading shotshells Ive also never deviated from any published data for fear of over pressures.
Now that I'm venturing into slug loading it's a steep learning curve and one with some uncertainty. I've been reading thru some old posts trying to get a feel for it. Unfortunately most old posts have had the photos removed by photo bucket. (The worst photo hosting site imo)
Anyway I'm willing to try anything within reasonable tolerances and will "ask the experts " if I venture too far off course.

[longbow]

A safe bet is to use equal weight birdshot load recipe and substitute a slug. It is generally accepted that slugs produce less bore friction than shot so pressures will be lower. In fact Elvas posted a "rule of thumb" apparently commonly used in Europe where when subbing a slug for shot in handloads they up the charge by 15% (IIRC bit don't quote me). A search will find Elvas' post. I have not tried that so no personal experience, just using it as another example that slugs generate less pressure than birdshot.

On the over pressure thing... I have some personal experience there that I'll share. About 30 years ago I blew up a shotgun. I was using the Lyman Foster slug and book recipe except... I was looking at short hulls so tried using gas seals with slug directly over top. Some worked and some didn't but after blowing a gas seal completely through a slug and a tube of lead popping out of the muzzle I decided I'd better fill those slugs! That was the combination that seemed to created the KABOOM!

So, I was using a Lyman Shotshell Reloading manual recipe which called for a cushion wad with petals cut off and PB but I was using shot hull with no cushion leg and filled slug. I shot a few through my Browning BPS and the were... let's say pretty potent loads and I got some sticky extraction but at that time I wasn't too bright (maybe not now either) so kept going. They seemed to shoot pretty well at least in comparison to what I had been getting so I figured I had "the load".

Next time out I took my Remington single shot and first shot it came apart in my hands. I was lucky as I was not wearing hearing protection of shooting glasses being in the bush and only taking a shot or two! I got sprayed in the forehead with powder and small shrapnel which drew a bit of blood, lost some hearing in my right ear but was otherwise unscathed. The entire top of the chamber parted company with the barrel and the barrel left the stock landing about 10' in front of me.

Examination of the barrel after the fact showed lead streaks from the short hull case mouth position to the forcing cone. My suspicion is that the shortened load was developing higher than normal pressure due to lack of cushion leg (= more volume at ignition when collapsing) and the slug obturated to fill the chamber (3" chamber and short hull) then met the forcing cone at about peak pressure and the slug just couldn't swage back down in time due to being filled.

Other than the gun exploded, the details are speculation on my part. I do know I couldn't have double charged because the load wouldn't have fit in the shot hull and the only powder I had was PB so not the wrong powder.

I do not recall the primer and it is possible that I used the wrong primer which may have added to the bad situation. If you are not aware primer changes in shotshells can affect pressure by up to about 3000 PSI so if you have a high pressure load already that could take it over the top. All 209 primers are not created equally!

So, yes I still reload shotshells and slugs but I do tread carefully and do not deviate far off published loads.

Most of my slug loading is from published recipes with minor changes of maybe wad or similar straight walled hull, slightly lighter payload, etc. My main slug load using Blue Dot for slugs over 1 oz. is based on a published load by Precision Rifle for their 610 gr. Piledriver slug. I have used slugs somewhat lighter and never loaded to their max. So far so good but even then I have had occasional sticky extraction due to...?

Since I have seen many hollow base slugs obturate to fill the bore and having seen the lead streaks in my chamber, I tend to use only thick skirted HB slugs these days because I know those Lyman Fosters with their thin skirts swell up to fill the bore. Mine cast at 0.705" but after recovery from deep snow they were bore diameter. That and wads jammed in the base may cause higher than expected pressures so I generally fill HB slugs as well... and I don't use short hulls with HB slugs anymore.

So the moral of the story is play but play safe!

You are taking the right approach in researching and asking.

Longbow

[finstr]

Thanks Longbow, I'm well aware of the difference in primers and like I said I have never deviated from the recipes as a rule. I generally don't reload trap loads. Kind of a waste of time really. I do reload heavy hunting loads that push the 11-12,000psi range using lead,steel,hevi-shot.

[finstr]

I disassembled a Winchester super X foster slug round


The powder looks to me like the old Win540. Not sure if that’s still possible or not.
Anyway it weighs 33.0 grains. The 540 is on the left;


The slug weighs exactly 437.5gr and measures .725”
I did this test because I have a couple foster slugs lying around that I assumed were the Winchester’s but apparently not as they are much smaller in diameter.

[SuperBlazingSabots]

Hello Finstr, I love it when you post pictures like that it helps visualize things much better.
You can load up the components back into another hull.

Ajay Madan

[finstr]

Yes but I can’t make the roll crimp as I don’t have that tool yet.
Anyway I decided to knurl some of the Lyman slugs I had cast to increase the diameter. I removed the wooden handle from the mold plug to use as a mandrel to hold the soft slug while knurling.



They’ve gon from .702” dia to .722ish. I’m powdercoating some now to bring them up to .725 ish and see what I get. The powdercoating will stop the bore from leading hopefully.

[SuperBlazingSabots]

Hello Finstr, you are good, keep it up and next modify the foster base pin to attach the wad:




Stay healthy and start cooking your own.

Best regards,
Ajay Madan
Super Blazing Sabots

[longbow]

If knurled to 0.722"(ish) then that would be a good candidate for paper patching with about 0.0025" paper. Not sure how well the paper will survive rough hulls and opening crimps but heavier paper worked quite well for me in the past. Still got some fliers but generally groups were much smaller.

Longbow

[finstr]

Ok I got a few powdercoated today. They’re coming out right at .724 on avg. Which is ok because they still
Fit nicely in the bore


They require about 5lbs of force to push thru



Beside the Win SuperX

[longbow]

Looking good! Those are so bright they might be like tracers!

I cast from soft lead those slugs will upset and fill the bore even starting from as cast 0.705" in my experience. They'll swage back down through a choke though.

Longbow