Lyman Foster slug test part 1

[tomme boy]

No they do not. I wish someone would though. The broach cut for the rifling is the problem. Unless that part is a 2 or 3 piece die set. You could have the rifled part. Then the base could be separate to form the base however thick you want. You just stack the dies.

[W.R.Buchanan]

tomme: It would be broached the same way some Allen Head Screws are broached. IE; short runs of specialty screws that the volume isn't large enough to justify a Cold Heading machine's time.

A hole is drilled to the minor diameter and then the broach is introduced and the chips roll into the bottom of the hole. Sometimes they are left in the bottom of the hole, other times you run the drill back in to break the chips out.

The aluminum part on the left in the picture was broached on my lathe with a rotary broaching tool, the one on the right is Stainless Steel and was sent to a broaching house. In both cases due to the size of the hex (1/8") the chips were smashed into the bottom of the holes and left there as there was no cosmetic point to removing them, you see this alot on Set Screws.

On a larger part like the Lyman Tool they would be removed. Reasonably sure that operation would have been sent out to a Specialized Broaching House rather than done in house.

Randy

[CANUCK]

If you guys fit your slugs directly to the bore dia do understand they will have to be lubed or they will lead the barrel like crazy. The thing about running these in wads is the wad acts as the lube. You could also powder coat them like we do for the rest of our Cast Boolits.
Randy

Just for argument sake say the full bore slug does lead the barrel.
I forgot to mention in my earlier post what I was thinking in regard to a possible leading issue.
When milling the mold larger why not leave a small section near the top of the shoulder alone effectively leaving a lube groove?
If the mold casts .705" and it was left alone in a section and enlarged to make .729" in the rest you would have 0.024" difference so a groove depth of 0.012" to fill with bullet lube.
May this work?

[longbow]

Not sure why leading would be any more of a problem, if as much as, in handgun or rifle since shotgun pressures are lower and gas cutting shouldn't be an issue since there are gas seals and/or multiple wads. If a guy used an bore size or larger soft lead slug I can see leading being a problem if there is no lube but there is also no reason not to put lube grooves on a shotgun slug... or knurl it then lube... or use a lubed felt wad under.

So far I haven't had any leading issues but then I use wheelweights or range scrap for pretty much all of my RB's and slugs whether they are bore diameter or wad slugs.

Longbow

[W.R.Buchanan]

Not so much with round balls as the actual bearing surface is close to a line around the ball.

With Cylindrical slugs it's a different story. You have a substantial bearing surface which is going to rub all the way down the barrel. The problem won't come from gas cutting, it will be from friction literally melting the outside of the slug. Powder coating might help but really there needs to be some radial grooves around the thing like grease grooves.

Or maybe that's another reason why Rifled Slugs have raised lands on them? I will be picking Brenneke's brain at SHOT in a couple of months.

Now,,, I see Full Bore Slugs working just fine in a Rifled Barrel as long as the fit is right and there is some kind of lube involved. With the amount of lube involved there might be problems with it melting and contaminating the powder in warmer temps and that's why I think the PC might be a better option.

Then we are back to the .73 cal rifle so whatever works for other rifles will probably work here too.

Randy

[megasupermagnum]

Not so much with round balls as the actual bearing surface is close to a line around the ball.

With Cylindrical slugs it's a different story. You have a substantial bearing surface which is going to rub all the way down the barrel. The problem won't come from gas cutting, it will be from friction literally melting the outside of the slug. Powder coating might help but really there needs to be some radial grooves around the thing like grease grooves.

Or maybe that's another reason why Rifled Slugs have raised lands on them? I will be picking Brenneke's brain at SHOT in a couple of months.

Now,,, I see Full Bore Slugs working just fine in a Rifled Barrel as long as the fit is right and there is some kind of lube involved. With the amount of lube involved there might be problems with it melting and contaminating the powder in warmer temps and that's why I think the PC might be a better option.

Then we are back to the .73 cal rifle so whatever works for other rifles will probably work here too.

Randy

The only time I had leading from shotgun slugs was when wads were pushing into the hollow base, and forcing the slug open, the slugs were even lubed. Last year I ran 50-100 full bore slugs, the Accurate 73-770S with ZERO lube. No wax, no tumble lube, and the light leading wash there was came out with an oiled patch. This was through a rifled gun. I highly doubt any lube can get past the substantial wadding that we use in slug reloads. Nothing used in shotguns is worse than the sloppy lubes used in muzzleloaders, and just a thin card or felt wad solves all problems there.

[tomme boy]

The raised ribs are to give the lead somewhere to go as it is swagged through the choke. That's it. No other purpose.

[Cap'n Morgan]

Longbow

Trust me; gas cutting is a very real phenomena even in shotguns.

Back in the seventies we used to shoot clay targets using the cheapest shells we could find. They were all of the felt wad type and they would cause an awful lot of leading right after the forcing cone where the pressure and heat is at its highest (and velocity is still quite low). We used to scrub the barrels with rolled spring brushes, resting the muzzle on our boots - and when you were finished there would be a small pile of lead on top of the boot.

An old skeet shooting pal of mine had tested some VERY cheap Polish shells with shot #9 on paper. Some of the shot had actually been fused together by the leaking hot gas as witnessed by the irregular holes in the paper. With modern shotshell plastic wads this is no longer a problem, but the gas leaking is still there. Often the wads have small channels to allow air to escape when being pushed into the shells during manufacturing, these channels prevent the wad from sealing completely when the shell is fired. Like the gas bleed holes in a semi-automatic it is hardly noticeable on the muzzle velocity, but it's there. I have also noticed that adding a x12x seal under the wad will increase muzzle velocity quite a bit. This, I believe, is because the seal helps to confine the pressure better than an ordinary felt wad in the first critical milliseconds before the payload starts to move into the bore.

[Blood Trail]

Here’s some 770 Accurate mold full bore slugs I lubed and the groups they shot at 50 yards. Never **** them without so I have nothing to compare it to.

NOTE: can’t find the pic of the groups. I posted it before here awhile back, but all three shots where touching at 50.


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[bikerbeans]

BT,

Them slugs look familar and my shoulder aches looking at them.

BB

[longbow]

Cap'n Morgan:

I believe there is gas leakage but with plastic gas seals it should be minimal. I've never seen any significant amount of leading even with unlubed full bore slugs. I tend to use wheelweights which doesn't tend to "rub off" like soft lead which is where I believe most leading in shotguns comes from.

I won't argue that there is much more gas leakage using card and fiber wads. In fact, I tried using old shotcups I had laying around after cutting gas seals off for use under full bore slugs. I thought I'd try a couple of nitro card wads over the powder like old timey loads then card card wad then shotcup with wad slug. Recovered wads were shredded!! Petals were black and melted. I was quite surprised at the result to be honest. Goes to show that the old loads must have used more powder to generate same pressure with all that leakage.

I have not tried the card wads over the powder under full bore slugs so no experience there and maybe that would result in some leading. I can believe there is enough gas leakage that the slug becomes the final seal so there leakage could lead to gas cutting.

Just not something I've had any problems with. Had lots of others though!

Longbow

[Blood Trail]

BT,

Them slugs look familar and my shoulder aches looking at them.

BB

Very similar to the ones you sent me.




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[longbow]

BT:

I'm hoping you are keeping a database of your load recipes! And are willing to share!

You've been loading and shooting a wide variety of slugs with many being much heavier than most slug loading data covers.

Unless a guy uses heavy shot load data for equivalent payload load data is sparse for heavy... or for that matter light (non-standard) slug weights.

I keep whatever load data I can find that may be useful for slugs.

Just saying...

Longbow

[Blood Trail]

I try to. That’s why the first thing I do is take pics and post it. Have about 2 years worth of load development got washed out when I left it on the back of my truck during a storm, I had to come up with a backup plan.


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