Where the leading is, tells me what?

[Texxut]

I just spent a full day searching the site with the "search" tool and still can't find what I'm looking for.
A while back, I remember a thread in which a poster was explaining where the leading was deposited and what it's location meant, and possible cures. I sure can't find that thread now. Can anybody shed some light on the subject?

[ku4hx]

Goto:
http://www.lasc.us/Fryxell_Book_Chapter_7_Leading.htm

and page down.

[evan price]

Leading in chamber end = bullet not sealing to bore. Too hard alloy, too small size, loaded too short (gas going around boolit), too hot of powder (Scorching bullet base too), undersized forcing cone, oversized chamber, etc.

Leading in muzzle end = lube running out of lubricity. Wrong lube, too hard of lube, barrel bore tapered, maybe too fast.

Leading all through in clots and chunks = Bullet stripping the rifling= lead too soft, powder too fast.

[MtGun44]

You missed, under "leading at muzzle end" - inadequate lube quantity for the conditions.

Bill

[sqlbullet]

Leading at the target only = Just right.

[geargnasher]

Leading at the target only = Just right.

That's a good one!

I have an issue with the theory that if a boolit leads toward the muzzle it's "running out of lube". If it does, where did it go and why? I've had loads lead terribly and recovered boolits still had lube in the grooves. I've also had loads that leaded and the recovered boolits were clean. I've had leading and a lube star at the muzzle.

Most leading is due to gas leakage around the boolit, and where gas leaks it abrades the lead. The dust created from this gas cutting action deposits in the barrel and is ironed on by the passage of the boolit. Following shots lead more by physical rubbing, since lead sticks to lead and the next boolit will leave more behind as it passes a leaded area. Same with copper fouling, it causes lead accumulation by physical transfer, like swapping paint in a circle-track car race. If a load leads near the muzzle, it's probably due to a gas leak somewhere behind the area that leads, either from a barrel restriction, leaks at the trailing edge of the lands due to improper pressure curve/alloy balance, or similar mechanism. Gas leaks that cause leading often blows the lube out of the grooves, but I seriously doubt it's "lack of lube" that is the true cause of the lead deposits. If the lube is gone before the boolit clears the muzzle, you can bet some lead dust went with it, and THAT is the cause of the leading.

I also have an issue with the theory that boolits will completely "strip" the rifling engraves if they're too soft, although they can seem to leak if accelerated too quickly. Col. Harrison disproved the idea that boolits can strip pretty well, and Richard Lee's "evidence" of stripping leaves much to be desired as far as real scientific analysis.

Gear

[fredj338]

Sometimes the bore is just rough & it's going to lead regardless of the fit, alloy or lube.

[Texxut]

Thanks for all the replies. I'll look at all those possibilities, make my changes one at a time, and let you know how it works out.

The load I'm working with is:
A cast 230 Lee mold TL RN.
Drops at 452" weighing 235 grains using wheel weights. Water dropped.
Tumble lubed with the Lee Alox/ Johnson PW/ Mineral spirits lube. Twice.
loaded as cast, over 4.0 grains Bullseye (one batch)
and 4.4 grains Bullseye (second batch).
COL: 1.270"
Function was flawless and accuracy was good.
Firearm: 5" 1911A1
Leading 1st 1/2 inch at breech end.

[fredj338]

Thanks for all the replies. I'll look at all those possibilities, make my changes one at a time, and let you know how it works out.

The load I'm working with is:
A cast 230 Lee mold TL RN.
Drops at 452" weighing 235 grains using wheel weights. Water dropped.
Tumble lubed with the Lee Alox/ Johnson PW/ Mineral spirits lube. Twice.
loaded as cast, over 4.0 grains Bullseye (one batch)
and 4.4 grains Bullseye (second batch).
COL: 1.270"
Function was flawless and accuracy was good.
Firearm: 5" 1911A1
Leading 1st 1/2 inch at breech end.
Stop water dropping. The combo of hard bullet, uberfast powder & low pressure is causing early leading. Not to mention, I have never been a fan of the TL bullet styles. I don't think they seal the bore as well as a heavy solid base w/ good size lube groove ahead of it.

[Texxut]

Stop water dropping. The combo of hard bullet, uberfast powder & low pressure is causing early leading. Not to mention, I have never been a fan of the TL bullet styles. I don't think they seal the bore as well as a heavy solid base w/ good size lube groove ahead of it.

I've got about 1000 of these casted up. You think I might get away with using Unique just so I can shoot them up, as apposed to running them back thru the pot?

[feets]

Try it and see what your gun likes.

It means another day at the range. Who doesn't want one of those?

[Sonnypie]

I've got about 1000 of these casted up. You think I might get away with using Unique just so I can shoot them up, as apposed to running them back thru the pot?

I call those pre-fluxed ingots.
(It does tend to make a mess of your pot to remelt loobed boolits.)
Have you tried W-231 powder? I use that to push 230g 2-groove and TL boolits out of my 45.
I like 5.5g of W-231. It's a real steel clanger! :Fire:

[fredj338]

I've got about 1000 of these casted up. You think I might get away with using Unique just so I can shoot them up, as apposed to running them back thru the pot?

You can try, but I think the bullets are too hard, maybe they'll run better w/ Unique, you have nothing to lose. Try running htem o/ 6gr of Unique, a ball equiv load.

[evan price]

I agree, way too hard of bullets for low-pressure 45 auto. WW clip alloy is right around 14-15 bhn anyway, water dropping it will probably have you up to18 bhn. In my experience anything over 12 bhn is too hard for low pressure cartridges.

I would personally cut your WW lead 50-50 with soft lead and then water drop that. (I like to water drop everything, they cool off faster and make a nice sizzle sound, AND they are like M&M candy- thin hard shell, softer malleable core.)

[Bret4207]

Tex- you say they drop at .452. Are you sure all of them are right around .452? No skinny ones in the mix? Are you sizing them at all? What does your barrel slug at, any idea?

I think Gears post, as usual, is worth reading about a dozen times and committing to memory. Of course, that's because he agrees with my thoughts!

[Texxut]

Bret,
The barrel slugs at .450" . I'm not sizing them. I did a random sampling to come up with the .452" size. I have a .451" sizing die, perhaps I should try that.?

I won't be water dropping any 45 cast bullets in the future. It seems, every time I depart from the norm, I end up with more work than it's worth. I've casted 1000's of 230 rn bullets from my RCBS two cavity mold , sized and lubed, and fired at ~830 fps with zero leading and good accuracy. Why I get a wild hair and decide I want change things is beyond me. A friend lent me a 6 cavity 230 RN TL mold and I knocked out a 1000. Where the water came in to this equation, I'm not sure, but It's out, I'm going back to what works.

The rounds I have loaded, I'll shoot knowing I'll have leading to clean. Not sure what to do with the other 800.

[youngda9]

Let this be a lesson to all of us about casting, and loading, so many before figuring out what load works for your firearm. Do small batches to get everything right before mass production begins.

[Bret4207]

Tex, you could try sizing a few and see if it helps. I imagine the quenching is altering your dynamic fit. You could try different powder charges and see if you can find you that will be more amenable to your boolits.

BTW- I went though the same phase where WQing HAD to be the answer. I learned it's just another tool best used when the gun indicates it needs it, rather than a "fix all" method and cure.

[runfiverun]

i flat out don't water quench unless velocity is up in the 1800 fps or above area.
or for a problem bbl.
i will try some softer stuff once i have a load figured out just to see what's up there.
but for most handguns and their cartridges,regardless of whether in a rifle or handgun, waterdropping just ain't necessary.

[BD]

In my experience leading in the first inch or so of a new 1911 barrel is often caused by jamming a .452 boolit with a square leading edge, through a .451 hole, (the end of the chamber in most modern 1911 barrels which also has a square edge). a small amount of lead is shaved off every time vaporized by the cloud of hot gas and ironed into the start of the bore by subsequent boolits.

You check for this by firing one round through a pristine clean barrel and then having a look. Shove a clean dry patch through and see what you get. In a new barrel without much throat you may also see little shards of lead at the start of the individual lands where they cut the groove into the booit.

You cure this by using a throating reamer, or by sizing to .451, or both.

It's been 20 years since any major manufacturer produced a barrel with a groove diameter of .452. yet nearly everyone insists that you should size cast boolits for a 1911 at .452. I'm still waiting for the plausible explanation of how that .452 diameter front drive band goes through that .4505-.451 diameter square edged steel opening without any lead being shaved away.

This is compounded by shooting unsized boolits, as these are not generally round.

5,000 or 10,000 rounds on down the road that sharp edge at the start of the chamber is more forgiving. Lot of lead scrubbing to reach that point though.
BD

[Texxut]

Thanks guys, I do appreciate all the advice and help. I'm going back to what I know works.

[geargnasher]

Stop water dropping. The combo of hard bullet, uberfast powder & low pressure is causing early leading. Not to mention, I have never been a fan of the TL bullet styles. I don't think they seal the bore as well as a heavy solid base w/ good size lube groove ahead of it.

My thoughts exactly. The load must be balanced, and WDWW at probably 20+ BHN with little to no tin in the mix, combined with weak TL driving bands and the third-fastest powder available in the known universe is about as far OUT of balance as one can get.



BD, the obvious issues of a sharp throat aside, I think I can answer you on the "why oversize". You want the boolit to be two things: Oversized and springy. Smokeless powder seldom "bumps" boolits of typical hardness to fit in the relatively low-pressure .45 ACP, and if it does, it's only for the first half-inch of the barrel before the pressure drops below the ultimate compressive strength of the alloy, so the seal will be lost anyway. You want your boolit to be of a reasonably flexible alloy so it will maintain bore obturation dynamically as it travels through, like a slighly oversized rubber ball going down a pipe. If all barrels were dimensionally perfect on a molecular level maintaining dynamic fit wouldn't be an issue, because the boolit would fit perfectly from engraving to muzzle.

I know typical air-cooled wheel weight alloy as a high elasticity, as I've done bore slugging experiments with different stuff, and the WW alloy will typically be at least a full thousandth larger after going through the barrel than a soft lead slug will. I realize that some of that is due to the harder WW boolit flexing the barrel steel like a snake swallowing an egg, but I've measured this stretch carefully in a 1911 barrel and it isn't nearly as much as the boolit's compression and springback.

The chamber/throat transition has to be smooth with no sharp edges, but the boolit still needs to be larger than the largest groove dimension so as to maintain outward pressure on the sides of the bore at all times. Logic would dictate that the metal displaced by engraving the rifling would help, but it never seems too. Either the whole boolit elongates or the metal gets wiped rearward into the lube groove(s), it never seems to make up for a boolit that doesn't fill the groove dimension plus a little.

The only thing that's ever made very soft alloys work for me was super-fast powders, particularly BLACK powder. My explanation (not proven) for this is that the incredibly fast pressure build would make the soft, non-elastic alloy bump up to obturate from the get-go no matter what the initial, static fit was, and then the pressure dies to nearly nothing so any leaks caused by the pressure fall and dead alloy don't do much damage to the boolit further down the barrel. No leaks =no leading.

Gear

[Bret4207]

Well, once again Gear has beat me to it, and more eloquently than I could have said it too. I would just add that unsized boolits often have their place in this mess. Saying a sizer makes then round is assuming an awful lot. I would be more inclined to say it makes them uniform. Not many are round, especially after they get loaded.

[BD]

The entrance to the throat on nearly every modern 1911 I've encountered has been less than .452 I don't care what the BHN is. I don't care what powder you use. You can not force a .452 boolit through a .451 orifice without shaving some lead. No way, No how. Most folks go along with the .452 sizing and put up with the cleaning needed as a result. It's not a big deal, but it's there. I size my boolits to fit the throat, use a RNFP style seated long enough to align the boolit with the throat, and shoot as many as I want between cleanings. Just like a .22 rimfire there is never any leading.

Pure soft lead, wheel weights, linotype. 1,000 rounds and no leading in my 1911s. I love this throat arrangement and like it in the .450 Bushmaster as well. Although the .450B is more generous at .453, the design is exactly the same. I've pounded 500 rounds at a time down the .450B at 45,000 psi and still experienced no leading at all with everything from soft lead to linotype.

I've addressed this issue with new cast shooters many times. Generally it's someone who has bought a box of commercial cast H&G #68 style boolits to lower their shooting costs and is experiencing some leading in the beginning of the barrel. If it's a new 1911, 9 times out of 10 just sizing to .451 greatly reduces, or eliminates the problem. These days it's the first thing I try.

I see these threads about leading in a new 1911 and read all the responses about oversizing the boolits and just wonder why folks don't try the simple thing, (and well proven in my experience), first? I don't have anything to gain from beating this drum. Just try it. Fit the boolit to the throat. It's not the final solution to everything, but in cast boolit shooting it's sure the most common solution. Sure, there are probably still some oversized throats produced. But these are not WWII Colts any more. Maybe one in 1,000 are significantly out of spec, the rest of them have .around a .4505 groove diameter and are throated barely enough to soften the beginnings of the lands, if at all. .451 is plenty, and will leave far less lead behind in most cases.
BD

[Texxut]

BD,
How do I go about slugging/finding the throat size in my 1911 barrels?
I have pushed a soft lead slug thru the bore from the muzzle end to the chamber, and measured that, to get a .450" measurement.

[Iron Mike Golf]

...You can not force a .452 boolit through a .451 orifice without shaving some lead...

Why not? Dies in my lubrisizer do that all the time. The swage (not shave) .001 to .002 all day long. There are no shavings building up.

[geargnasher]

BD, if your 1911 is shaving lead, it must have zero throat and a perpendicular edge where the lands meet the end fo the chamber. Something else is going on. I have a .45 Colt rifle that gobbles up .457" boolits (.452" groove, 447" bore) all day long. It has a very large throat and chamber and is most accurate with the .457" boolit. The only time it leaded was when I worked up the pressure too much for the alloy and shallow rifling, which was way up into Plus P territory with air-cooled 50/50 WW/pure plain-based boolits.

Gear

[Sonnypie]

Why not? Dies in my lubrisizer do that all the time. The swage (not shave) .001 to .002 all day long. There are no shavings building up.

Excellent point Mike.
The reason I size mine is for consistency.
But every-bodies mileage may vary. :coffee:

[BD]

Revolvers have forcing cones, most rifles have tapered "ball throats", your sizing dies taper gradually from about .458 to .452 or whatever size you use. The 1911 barrel has none of these mitigating factors. The 1911 barrel has a chamber that ends in a hole with square edges. In theory the case headspaces against this ledge. Pull your barrel out and look at it, you'll see what I mean. Or look at a finish reamer.

Most of the finish reamers I've seen have a very short minor diameter section just in front of the chamber which removes about .10 of lands from the start of the barrel. It's the diameter of this resulting very short "freebore" that matters to the boolit size. In a hand fitted 1911 this reamer is followed up by a throating reamer which cuts a very short beveled section in the start of the lands. This used to be done by hand, and by feel. The results varied and the short "freebore" section typically got opened up a little as well. Boolits had a little more gradual start into the barrel. Many of the modern barrels I've looked at do not appear to have ever felt the touch of a throating reamer, and the start of the barrel is abrupt and square. It could be that the modern production barrels have the chamber and throat cut in one operation somehow, I don't know.

I measure this diameter by bumping up a soft round ball and tapping it into the chamber from the rear until it forms an impression of the start of the barrel. Although I've pretty much quit measuring them as all of the new ones have been .451 or under for years. Look at your barrel. if you can't seat a .452 SWC out of the case at least as far as the freebore in your barrel and have it chamber every time, IMHO you are sizing too large. IMO the reason so many folks claim that a SWC should be seated out "just a finger nails thickness beyond the case mouth" is that the .452 boolits they're using won't enter the throat. They are effectively headspacing the round using the SWC step against the end of the chamber.

I own a throating reamer which I use to put a slight taper on the start of the lands. All it takes is a twist or two by hand and it's done. It doesn't open up the freebore at all. I've throated about 25 barrels this way and I've lent the reamer to another 20 or so folks, many of them on this forum. To this best of my knowledge this in combination with a properly fitted boolit has cured the issue every time. I know that in combination with boolits sized at .451 it has cured the issue in every barrel I've done myself.

All I'm saying is that this works most of the time to cure leading in the first inch of the barrel. It's no "secret", I didn't invent it, I just use it because it works. There are certainly other issues that can cause leading, but if what you have is a new barrel, and it leads in the first inch. Try this.

I'm gonna quit beating this horse now.
BD

[mroliver77]

Bd,
Thanks for your info. While I size .452 I have no leading in my 1911's. I accidentally sized some in a .454 die. They came out .4535. I do get a smidge of lead in the first 1/8" of the barrel with these.
Now I have to take an impression of my barrel(throat).

To the original poster. You could heat the boolits to just under slumping and then shut off the oven letting boolits cool slowly. They would be as sft as your alloy could be.
J

[runfiverun]

the point about things not having to be oversized is quite correct, they need to be correct sized.
if you have a straight consistent bbl you can size to the diameter of the bbl.
i use 224 in my 223 aand 358 in my 358 winchester [my two fastest cast shooters b.t.w.]
the oversized generally comes into play for oversized throats or cylinders.

[geargnasher]

BD, thanks for the detailed explanation, and it's not a dead horse if people keep learning from it! Personally, I've never quite had that issue, but all of the .45s I have have had so many J-words run through them over the years that the sharp edge is long gone and I never knew that it was there. I've lapped a couple of "plastic gun" .40 throats to break the edge using a TC j-bullet with the nose tapped for a cleaning rod and embedded with Clover compound, seemed to help lots of things including leading.

Gear