lyman foster slug Q's 12ga

[wonderwolf]

I've cast up a bunch of those lyman foster 12ga hallow base slugs and have a few questions

Looking at the load data and talking with other members I'm getting mixed info on whether or not a ROLL crimp can be used with this particular projectile. The general concern is that the rounded ogive of the slug does not unroll the crimp but rather lodges itself in it until pressure builds up and its pushed free obviously spiking pressures to a possible unsafe level. Looking at the lyman book it says I can roll crimp but I can not discern what the wad stacking order is, if a card wad goes over the top of the slug or what?

Recently I tore down a similar projectile however this one was rifled, but had the same idea in shape and form. It was from a dud "Buck Master" slug I found at the range. It was roll crimped and other than the rifling it looks about the same might have a slight touch of a edge like transition(from the tooling that rifled it I'm guessing) from body to nose but not much more than the lyman.

So How were the lyman foster slugs intended to be loaded using a roll crimp? I used pure lead to cast the 100 or so that I have on hand still but I think a harder slug might be a better option with harder targets....such as junk cars and the like.

[woody1]

I load 'em with a roll crimp. No card over the top of slug. Regards, Woody

[longbow]

I have loaded the Lyman Foster and several sizes of round ball using roll crimp with no problems.

I did have an incident with an undersize slug in a shotcup. It was even slightly loose in the shotcup. I pulled the trigger on the first one and recoil was pretty stout! Extraction was sticky and the hull was missing a hunk of its mouth.

My take is that the roll crimp edge got caught between the slug and chamber wall so tore off and became a passenger with the slug. I elected not to shoot any more.

I have not had any problems with any shape of bore size slug or tight fitting slugs in shotcups using roll crimp.

Longbow

[wonderwolf]

Some of the lyman data talks about a BPI gas seal, How were you stacking wads with a shot cup? or was this a totally different style of slug?:Fire:

What was the make of the undersize slug? what diameter ?

[mikenbarb]

I only roll crimp my shells when I load Lyman hollow base slugs because their design isnt meant to crimp and will collapse the hollow base. I use old book Alcan PGS and Combo wads along with Fiber Felts or Feltran Blue Streaks to load them in paper hulls. I sometime use plastic ones if their new because the crimped ones wont roll crimp good and make a messy roll.
Just remember that roll crimped slugs have a max OAL also just like rifle cartridges.

[longbow]

I started out using the Lyman slug recipes under a Lyman Foster slug but so far have really not managed to make it shoot consistently.

I have tried:

- Box stock book recipes
- filling the hollow base with hot melt glue to keep the wads from pushing in
- wheelweights instead of pure lead
- paper patching to bring the sadly undersize Lyman Foster (0.705" dia.) to bore size
- on shotcups with the petals cut off (cushion leg only)
- on hard card wads with plastic gas seal (this is the stacked wad column)
- combinations of the above

So far I have not gotten decent or consistent accuracy from a Lyman Foster slug ~ too big to fit into a shotcup and too small for the bore. Not saying it can't be done, I just haven't succeeded so have gone in other directions.

SluggerDoug solved the problem by "knurling" to bring the slug up to bore diameter. He has a very good post in this forum.

What has given me best results so far with all slugs and round balls I have tried is to use a plastic gas seal (usually cut off a shotcup) over the powder then nitro card wads or hard card wads to bring the wad column up to height.

The BPI gas seal is just that and is available from Ballistic Products Inc. I think it is also used as a seal for some of their shotcups.

My best results to date are with the Rapine 730550 Foster on hard card wads with a plastic gas seal over the powder. That one gave me 2" groups at 50 yards. I haven't shot them further but still have a few to test. 0.735" round balls give me 4" to 6" groups at 50 yards and are pretty consistent ~ generally better than slugs from my guns, other than the Rapine so far anyway. Got more testing to do.

The undersize slug was one I made a mould for. It was intended for heavy petal steel shotcup in a rifled barrel. I decided to try a Brenneke style with it by attaching base wads and using a shotcup as a sabot. The wads were a tight fit but the slug was still slightly undersized so I think pinched the roll crimped case mouth. Not a situation you would normally run into.

While the Lyman Foster is undersized for the bore I have not had trouble roll crimping for it.

Longbow

[SluggerDoug]

This is part of my post from 02-09-2008 titled - Acurracy with Lyman Foster style 12 ga. In that post I had some photos of my slugs, wad colume and crimp. Good luck.
"I started to load my own Foster style 12 ga slugs in the late 70’s , using a Lyman mold and roll crimp in 2 ¾ slug casings. It was a long hard learning experience just to get to factory like accuracy. But eventually, I got better then the best factory accuracy (availble at the time) and better field performance on deer. Out of a good smooth bore with a scope, 5 shots would group into 3 inches at 75 yds. Some SB guns shot it better. Here is the short story,
I believe the secret to an accurate Foster style slug (esp. in a Smooth Bore) is that it must expand rapidly and evenly in the CARTRIDGE as it is fired. The slug expands its outside diameter by collapsing in length by the force of the powder behind it and weight of slug front section and the resistance of crimp ahead of it. It then has to enter the forcing cone concentric to the bore. If it has expanded properly in the case/chamber, it will swage down to a perfect bore size and be quite accurate. If the nose is not concentric or the base is at an angle to bore the slug will not be accurate.
This became apparent when I retrieved fired slugs from a snow bank behind my back stop one year. They were about half their unfired length and were a perfect fit in the bore of my gun. These were factory slugs and I could tell the accurate Winchesters from the poor performing Federals just by looking at them, the Winchesters at that time had a star on the nose. The Win. Nose and base were square to sides but the Feds were at and angle. I felt the Wins used a faster burning powder as the recoil was a quicker jab and less flame came out of the barrel, but that was just my guess at the time. Dissecting loaded rounds showed the Winchester slug to have a larger base diameter and a thick hard card under the slug, Federal lacked any HC, the slug was on top of a fiber like wad. So I tried to duplicate the Winchesters as best I could.

WHAT I DID WAS,
1. Slugs must be cast very soft, use pure lead. (Or as close to it as possible, cable sheathing, lead pipe)
2. Slug must be loaded concentric in cartridge case with roll crimp centering nose and holding slug firmly in place. The best way to do this is make slugs fit snugly in the cartridge case, their diameter should be .725 -.740 diameter. The undersized .690 cast slug will certainly expand to fill the inside diameter of the shell case when fired, but the trick is to do this while staying concentric (in line) with the bore.
( I did this by roll knurling the Lyman slug up to about .735 diameter. As cast it was about .690. I fit the slug on a pin shaped like the molds plug, the pin was pressed into a ball bearing mounted on a plate. A pivoting lever had a hand crank with a helical gear mounted inline with side of slug (when on the pin). By pivoting the lever to engage gear into side of slug and rotating crank once or twice it engraved “rifling” on side of slug, expanding the slugs out side diameter. This was controlled by an adjustable stop for the lever. For lack of a better term I called it a “slug rifler”. I never tried other methods but I think I would see if just expanding the base diameter to about .735 with something might work, it would be slightly bell shaped, but much simpler then what I did)
I do not believe this “Rifling” caused the slug to rotate, but besides making the undersize slug larger in diameter to fit the case, it made its side walls weaker and easier to collapse and expand quickly when fired. Plus it looks cool ;o)
3. Use a substantial Hard Card column under slug, ¼ to ½ inch tall. Then a fiber wad column that compresses easily under the HC. I used a BPGS or cut a AA wads gas seal section off, for over the powder wad. I used Circle Fly wads for the HC and Fiber. I ended up using 4 .125 thick HC.
4. Use a near max. charge of fast burning powder to help expand the slug in cartridge quickly. I had good results with IMR 7625 and WW 571. (37 grains of IMR 7625 with the 1 oz slug in the 2 ¾ load was very nice, Lyman gave 1575 fps for its velocity, probably out of a 28" barrel)
5. I gained some accuracy by filling the slugs cavity with dense granulated plastic. This helped to assure the Hard Card under the slug did not blow into cavity of slug and it made the fired slugs cavity a bit bigger, making for slightly longer side walls touching barrel.
6. I was able to cast heavier slugs by placing a small washer under the moulds shoulder screw that he cavity plug locks into, I found 1 1/8 (495 grain) shot good out of a SB, and plowed through brush better then the 1 oz. Long range penetration on large deer was also improved. Anything heavier then that seemed to only shoot good out of a rifled barrel.
7. A good tight roll crimp is important, but I found I did not need once fired cases. I would put Crossman Co2 cartridges in the empty case mouths for a few days prior to loading and got good crimps even after 3-5 firings.
* If you don’t get good accuracy you must try to recover some slugs to see what is going on, soft back stop at the farthest distance you can should work.
8. I used a drill press to roll crimp my slugs and felt it helped accuracy by making the crimps more uniform. I would hold the shell loosely on DP’s table and drop the spinning crimper slowly on to shell mouth till shell spun slightly in my fingers and found its center. Then griping shell tighter I would lower crimper slightly and hold for a couple seconds while it heated shell mouth slightly, and then I ran the crimper home. That said, a friend who also loaded these slugs got reasonably good results with a hand drill.
9. I pan lubed my slugs when I switched to rifled barrels to keep leading down, but never tried lubed slugs in a smooth bore. The lube filled the grooves of the “rifling” and I used an empty case with primer out and a plunger inserted thru hole to cut slugs frI took some photos of some old loads, slugs and the wad column I used. Note the cicle on top of the slugs where my crimper spun, it is a home made crimper but worked great.
First photo is of one of my unfired rifled slugs with plastic filler , as cast 1 3/8 oz and a fired 13/8 oz, fired from a rifled barrel
om lube pan and just push plunger to get slug out of case.
Doug"