Need measurement on Lyman 12 gauge Foster Slug (cast slug)

[bedbugbilly]

I am hoping that someone here who has a Lyman 12 gauge Foster Slug mold, and who casts in it, can provide me with the actual cast slug outside diameter?

I know that they claim it is .705", but after casting in Ideal and Lyman molds for close to 60 years - what they say isn't always the actually is. :-)

To explain . . . years ago, I had a .69 cal. rifled musket (Civil War) that had the barrel reamed post Civil War to be used as a shotgun. I had a fellow give me some 12 gauge slugs cast in a Lyman Foster design and they shot very well out of it. I sold the gun a number of years ago. I now have another .69 caliber rifled musket that is an over size bore based on a .69 cal. Mine Ball cast in a Ideal mold I have. A .69 caliber minie is a huge piece of lead and if I could get a Foster slug to work - may have to size it down - they would be cast out of soft lead - it might be an ideal boolit to do short range plinking with - so just need to know what diameter they truly drop at if someone could measure done they have cast with a micrometer or a digital caliper.

I am having issues with getting a good bore measurement on the barrel, but it appears it might be a .001 over .700 or thereabouts. It might work to size a slug if it is close and then use a short stater to introduce the slug into the bore and then seat with the ramrod. Any help on the measurement would be greatly appreciated. Thanks!

Jim

[centershot]

Billy, I can't help you with the dimensions you are seeking, but if it's plinking ammo you're looking for, the Lee 0.690" RB mould would work well, especially if your bore truly is 0.700". A 0.690" RB and a thin cloth patch would work pretty good!

[CastingFool]

I have a bunch of those that I cast years ago. Just miked a few and they measure .695" at 90 deg from the seams and .702"-.704" across the seams. Amazingly enough some are still shiny as if cast a few days ago, even though they were cast about 1982. Needless to say, my attempts to reloading slugs did not go far.

[bedbugbilly]

centershot - thanks - I think I just read a thread on this site a few days ago ? talking about the .690. I do have an Ideal .676 that was made with the old original .69 rifled/smoothbore muskets in mind to be used patched. My interest in the hollow base Foster slug if it would work is because it would be easy to use just like a minie like we used to do when I was shooting N-SSA - lube the base an load and the skirt will expand to fit bore.

I don't shoot a lot of offhand anymore as I have some foot issues and my balance is not the best - so I usually try to shoot off of a bench or a portable one. If a Foster slug could be made to work - it would be great. I have even given some thought to having Bobby Hoyt sleeve the barrel to .58 caliber as i still have all my molds and the Ideal/Lyman 575-494 SWC that we used to use would be a good boolit out of that bore. Just trying to find out to see what my options are. I will certainly keep the .690 RB in mind though.

Jim

[bedbugbilly]

CastingFool - many thanks for taking the time to measure some - I greatly appreciate it. That gives me what i need to know and now I can try and get a more accurate measurement on my bore. I may have to take the barrel and remove the breech plug and put a plug down about 1/2" or so from he muzzle and do a soft lead poor , then use a ramrod to push the pour out to measure. Or locate some of the material they melt and use for casting chambers. Three groove military shallow rifling so no easy way to take a measurement.

Many thanks again - greatly appreciated!

Jim

[CastingFool]

You're welcome! Glad to be of help.

[NavyGuns45]

I just measured a few I have, cast from WW. They weigh .685" across up front and .670" on the skirt end.
***EDIT: Aw heck, I just realized you are talking about the Foster slug, not the 525 grain air gun pellet-looking one (the one I have). Sorry!

[longbow]

Mine cast 0.705" though I would have to check a few to be sure. That is what I recall though. Too big for wad and way too small for the bore (of a 12 ga.)! Dumb! If cast from pure lead they do obturate to fill the bore so why not just make them bore diameter in the first place?

I don't have them anymore but I collected several shot into very deep snow and they all showed uneven bump up and accuracy reflected that in my opinion... or lack of accuracy I should say.

If cast from soft lead you should be able to size them down to suit your bore diameter. I made a hammer through sizer for Lee slugs to remove the taper as they have much more taper than the petals on the wads I have. Plan was to paper patch back up to proper fit with wad/bore. That works but is too much trouble. Also, I cast the Lee slugs from wheelweights and they cracked when sized from 0.685"+/- to 0.665" to remove all taper. I had to open up the sizer to 0.675" IIRC then the cracking stopped.

Point being that if you are sizing down by 0.005" to maybe 0.010" it shouldn't mater if they are wheelweight or not but if you have to size more than 0.010" soft lead will have to be used. If you want them to act like a Minie and with expanding skirt to engage rifling you'll want soft lead anyway. That skirt is pretty thin so you may have to use fairly light powder charges or make a new core pin to give thicker skirt.

Longbow

[bedbugbilly]

Thanks Longbow - that info helps. Years ago on the bored out .69 I used them in, I used soft lead and didn't have to size them. Like you say, the skirts are thin and IIRC, I used about 40 grains or so of 2F Goes and had good results at around 50 yards and maybe a 10 inch or so group at 100. That was resting over a stack of bales of hay and my eyes were much better in those days!

I have a pretty stout single stage press that does a good job when I size my Smith carbine slugs down through a push through sizer. I have two molds . . and Eras Gone that drops at .517 and a NOE that drops at .518 0 .5185 - I size them to .515 for my carbine.

I would need the 12 gauge slugs to be soft lead to skirt expansion but it's a double edge sword . . . size down too much and run the risk of deforming. I'm thinking a push rod with the end turned to fit the hollow base and maybe even a ledge on it to support the skirt and push them through nose first might work if the push rod OD and the sizing die ID had close tolerance. Food for thought anyway.

Thanks to you all for the info and suggestions - greatly appreciated!

Sincerely,
Jim

[longbow]

One of the members here reforms Lyman Foster slugs but swaging up to 12 ga. bore diameter so bigger bump up than what you want to do the other way. IIRC he uses a swaging die and punch shaped to support the skirt base and fills the cavity.

Seems to me I ran into his post recently but it may have been an old post I found during a search. I don't recall poster's name.

You are going the other way but a sizing die and punch/ram of smaller diameter but same shape as hollow cavity should work to size down O.D. without deforming.

Depending on punch diameter you can form a somewhat thicker skirt when sizing down.

Longbow

[dogrunner]

Just now saw the question. Mine, cast of pure lead, measure a consistent .710. Never did get around to working up a load for some that I paper patched........intended to try 'em in my Hastings A/5 bbl.............If I do, I'll post.

[woody1]

FWIW, my 12 ga. Fosters average .706" cast from WW.

[a danl]

One of the members here reforms Lyman Foster slugs but swaging up to 12 ga. bore diameter so bigger bump up than what you want to do the other way. IIRC he uses a swaging die and punch shaped to support the skirt base and fills the cavity.

Seems to me I ran into his post recently but it may have been an old post I found during a search. I don't recall poster's name.

You are going the other way but a sizing die and punch/ram of smaller diameter but same shape as hollow cavity should work to size down O.D. without deforming.

Depending on punch diameter you can form a somewhat thicker skirt when sizing down.

Longbow

that could be me you're talking about

[longbow]

Could be! I couldn't remember the name but remembered reading the post.

Slugger Doug took the same tack of expanding the Lyman skug but by "knurling" it using a cavity filling plug and helical gear to swage "rifling" on the O.D.

He also said accuracy was much improved with the slug bumped up to bore diameter.

Two different ways of achieving more or less the same thing.

Longbow