Foster Style Slug molds

[gmww]

While thumbing through my many catalogs I saw the Lyman 1-Cavity Shotgun Foster Style Slug Molds. It says the 20 Gauge is .605, and 345 grns. The projectile basically looks like an upside down U shape if you cross sectioned it. Claims it doesn't need rifling.

I was wondering about the large hollow cavity. Would that air space create a situation where you would bulge your barrel if fired in a ML?

 

[Norskie]

Seems as if we'd have heard if that air space is equivalent to a short started round; i.e., large enough to cause a barrel bulge. This slug is essentially a large minnie ball.
A smoothie barrel has thinner walls, but not that thin. Heck, if you want to be on the safe side, put a felt wad under it and stuff the cavity with lube.

 

[gmww]

Heck, if you want to be on the safe side, put a felt wad under it and stuff the cavity with lube.

I was thinking another solution would be to use a lube filler.

 

[paulvallandigham]

Unless you are shooting a muzzle loading shotgun, or fusil that has so thin a barrel that it should not be shot anyway, the cavity will not damage the barrel. This is basically a " Minie " ball in design, and the thinner skirt will actually try to expand to bore size. It would be important to load your gun using an overpowder card, then a cushion wad under this slug, and an overshot card on top of the slug( or two of them to be sure) to hold it in place and keep the slug from moving forward in the barrel before firing.

You might be able to use a thin cloth patch with this slug, to protect your bore, but I would not want to rely on it to seal any gases, or survive intact to get this slug out the barrel. Maybe some of the new teflon patching would do this, but not traditional cotton and linen patching. Considering that without spinning, these traditional foster slugs are about as accurate as a PRB over the same ranges, I don't seen any advantage in using them. I have used these with great effect in a modern shotgun that will print 3 slugs in one hole off hand at 50 yds. At 75 yds, they still hold a decent group. at 100 yds, where the slugs has dropped through the transonic range, and is now traveling below 1000 fps, the groups open up dramatically, and luck becomes more a factor in hitting a deer broadside with a killing shot.

I have not tried working up loads with this slug where the velocity is held below 1100 fps at the muzzle. That is the secret of the long range accuracy of the slug gun shooters. You might get better accuracy at 100 yds by reducing the starting velocity with this slug. At some point, without spinning, it begins to act like a badminton birdie in flight, fishtailing back and forth. In a rifled barrel, I understand that some shooters have been getting great groups out to 200 yds.

 

[Bountyhunter]

I have not tried these, so let me ask this. On the BP Cartridges we never put a card under a hollow based bullet, lest it fill the hollow and the bullet not expand.

If this bullet were rammed right down on loose powder, the powder should fill the hollow base and there should not be any air space to speak of. Am I missing something here?

 

[gmww]

I was thinking the same thing. I was worried for the time that even when it's pushed down on loose powder the hole doesnt get filled. Course it's a what if. I'm also thinking this might be a good projectile for a rifled .62 cal.

 

[faw3]

GMWW if these are what I think they are they are for Eflant killing real close range stuff, now in my Zep 100 + twist????? Maybe I should find out? PM me the info please Fred :hatsoff:

 

[gmww]

You've got Mail! Fred. :grin:

 

[paulvallandigham]

If this was a BP cartridge, it would be shot thorugh a rifled barrel. This question appears under the Smoothbore heading, so I suspect the man wants to use a foster style slug in his 20 gauge shotgun, fowler, or fusil. Being a smoothbore, rather than rifled, you have real problems with this slug expanding enough to seal the bore. Most 20 ga. guns are bored .615 to .620. Mine is larger. Even at .615, that is .010 larger than the diameter of the slug as it is listed. You can use .005 " patching with that kind of slug, but such thin material is not likely to survive the trip down the bore, even if it does seal. That leaves using a hard overpowder card wad, and then a lubed cushion wad under the slug to seal the gases, lube the barrel, and give support to the slug's rim. I also would use a over shot card to provide a smooth, hard, surface on top of the cushion wad to keep the cushion wad from trying to drive up into the hollow cavity. I think that will give the best accuracy combination.

If you don't mind shooting 5-8" groups at 50 yds, then go ahead and put that hollow based slug down on the powder without any wads, and hope it expands to seal the bore. If you will use a chronograph on these two different loads you will find major differences in velocity, and in shot to shot variations between the two loading systems. And, accuracy will be bushel basket size with the bare ball load. You could try paper wrapped slugs, but you would only be able to wrap once around the slug if you want to get it down the barrel of a smoothbore. Its a lot different than shooting a similar slug in a rifled musket.

 

[paulvallandigham]

If this was a BP cartridge, it would be shot thorugh a rifled barrel. This question appears under the Smoothbore heading, so I suspect the man wants to use a foster style slug in his 20 gauge shotgun, fowler, or fusil. Being a smoothbore, rather than rifled, you have real problems with this slug expanding enough to seal the bore. Most 20 ga. guns are bored .615 to .620. Mine is larger. Even at .615, that is .010 larger than the diameter of the slug as it is listed. You can use .005 " patching with that kind of slug, but such thin material is not likely to survive the trip down the bore, even if it does seal. That leaves using a hard overpowder card wad, and then a lubed cushion wad under the slug to seal the gases, lube the barrel, and give support to the slug's rim. I also would use a over shot card to provide a smooth, hard, surface on top of the cushion wad to keep the cushion wad from trying to drive up into the hollow cavity. I think that will give the best accuracy combination.

If you don't mind shooting 5-8" groups at 50 yds, then go ahead and put that hollow based slug down on the powder without any wads, and hope it expands to seal the bore. If you will use a chronograph on these two different loads you will find major differences in velocity, and in shot to shot variations between the two loading systems. And, accuracy will be bushel basket size with the bare ball load. You could try paper wrapped slugs, but you would only be able to wrap once around the slug if you want to get it down the barrel of a smoothbore. Its a lot different than shooting a similar slug in a rifled musket.

I am shooting a .600 Round Ball, by contrast, in my .626" diameter fowler. That give me a lot more room to try different patch thicknesses, wads, etc.

 

[musketman]

If you load it backwards it would look like a hollowpoint roundball... :hmm:

 

[Wes/Tex]

Funny you should mention it...I usesd to have a .70 M.1809 Potsdammer musket and used inverted .69" Minie balls for the stake shoot. I'd tell the bunch not to shoot till after I hit the stake, then cut it in half! Really sent the splinters aflying!!

 

[faw3]

And mine likes 600s not 610s? We both have the same made barrel. (GMWW and I) Fred :hatsoff:

 

[paulvallandigham]

fred: Were your gun shoot this .605 Diameter slug? Paul

 

[faw3]

Got no idea, would think so. Ive got 2 rifled and one smooth, it was mase to shot ball or shotgun 2nd. A 610 ball is tight the first 2". Fred :hatsoff:

 

[gmww]

Hey Fred, I inserted my stainless steel, midway usa, $19.00 special micrometer into the bore. I got a reading of .62. Originally I got .615 but slowly rotated it to see if it was any larger and got .62.

So it would seem the .605 will fit. Will it seal properly? Anyone got some of the slugs you want to send my way or Freds for testing? :hmm:

 

[paulvallandigham]

The only experience I have with this sized foster slug was to put it into a 12 gauge plastic shot wad cup, and shoot it out of a 12 gauge gun. The plastic wad sealed the barrel, with just an overpowder wad under it, and the slug shot very well. The downside was the plastic streaks in the barrel that had to be cleaned out with a bronze brush and a solvent. Choose your plastic cup wisely. Ballistics products makes a straight walled cup that is preferable. The ordinaly ones curve at the bottom, and this tends to pinch, and round the bottom of the skirt on the slug. If you have a couple of .20 ga. wads, you can put them down the shotcup first, and put the slug on top of them, to eliminate that problem. We had groups at 100 yds, in the 3 inch range using the 20 ga. slugs in 12 ga. guns.

 

[TN.Frank]

Seems like I ask about the same question only about the Lee 12ga slug mold,LOL. :hmm:

 

[gmww]

Enquiring minds gotta know! Actually I looked at those Lee slugs. Seems they have the partition in the middle if I'm thinking of the same ones. I dismissed the possibility thinking the partition would hinder the expanssion of the skirt in the hollow cavity. :hmm: Now if it's going into a shotgun wad then it doesn't matter I suppose.

 

[paulvallandigham]

Actually, the presense of any kind of post, or bar in the hollow gives the slug some axial stability in flight, and actually makes it more accurate. But, we are talking about general accuracy within that 75-80 yd. range before the slug slows through the transonic zone, and the vaccuum at the back of the slug either disappears, or moves forward past the slug, turning it with any imperfection. But, you do need to consider whether that skirt can expand, and use wads accordingly.