cast load development and detecting leading

[oley55]

I have developed plenty of loads for jacketed ammo, but not so much for lead and I am struggling with the process. With jacketed ammo it's pretty straightforward, watch for pressure signs and keep going until you find your optimal load, stopping when excess pressure signs are detected, or upon reaching your max load.

For this discussion, let's assume the bullets are appropriately sized for the barrel, and weapon. With cast, it seems the process is the same except for barrel leading. Or is it all about leading?

1. what is the best process for detecting barrel leading? Visual inspection, running a patch feeling for the lead fouling, or combination of both?

2. how often do you check for leading? after each shot, third, fifth?

3. how often do you clean the bore? after completion of each load?

4. is it likely you will ever get to excessive pressure signs without first having encountered leading?

5. confirm you keep going until you; get leading, experience excessive pressure signs, or reach max load?

It seems like there are so many variables with cast bullets; too soft, too hard, PB, GC, lube, fast powder, slow powder, that I am having trouble getting my arms around it all. So this is an attempt on my part to eat this elephant one bite at a time.

[Nick_C_S]

I think everybody is afraid to chime in lol. It's a huge subject and few answers are definite. I am curious for what purpose(s) do you plan on loading lead? I load with a lot of lead - the primary purpose is for 38 Special target shooting. Nothing shoots straighter than lead - at least, for my application. My hottest round is a 158gn SWC for 357 Magnum that runs about 1100 fps. It will visually start leading the barrel in about 30 rounds or so. When I'm shooting them, I infuse the occasional cylinder full of jacketed ammo to clear the lead. They say this damages the barrel. Well, I've been doing it for over 30 years - I'll let you know as soon as I start seeing barrel damage. In the course of this post, you're going to get claims of people running their lead slugs to over 1500 fps with no leading whatsoever, and on and on. Me, I've never shot lead without it leading - ever - under any circumstances. Lead leads - period. And then they'll go on about barrel fit, slugging the barrel, etc. Okay. Whatever. My barrels must all be the same size because they all behave the same with lead. And all my lead bullets are .358 - as 99+% of them out there for sale are - so what's the point in checking all this stuff?? You're going to end up right were you started. I digress. I'll try to answer your questions:

1. what is the best process for detecting barrel leading? Visual inspection, running a patch feeling for the lead fouling, or combination of both?

Visual. I use one of those flexible bore lights. They work great.

2. how often do you check for leading? after each shot, third, fifth?

In the field, I rarely check - unless I'm running an experiment with something hot. So my inspections are usually when I get home after a shoot and when I go to clean my gun (which is after every shoot).

3. how often do you clean the bore? after completion of each load?

After every shoot. Usually after about 200 rounds.

4. is it likely you will ever get to excessive pressure signs without first having encountered leading?

I doubt it. From my point of view, all lead bullets lead the barrel to some degree. Lead is soft (duh) and smears into the bore - that's all there is to it. But I have no need or desire to load any lead round that hot. I'd just use jacketed.

5. confirm you keep going until you; get leading, experience excessive pressure signs, or reach max load?

Talking about during a load work up? I go until I reach my purpose goal. Because my goals are realistic, I rarely run up against any of those to any major degree.

Maybe this will help some more. . . He's some of my lead loadings, and their purpose:

38 Special 148gn DEWC for IDPA Power Factor - 710 fps required to make PF. I use a Missouri Bullet Co (MoBuCo) soft cast slug (BHN 12). This is a soft slug that is extremely accurate. My worked up loads run about 750 fps (there's four of them actually - using Bullseye, AA2, W231, and Nitro 100). After about 200 rounds, the first 3/4" of the breech of the barrel has considerable leading - as does the cylinder throats. Actually, I think the leading plateaus after about 100 rounds of so; after that, the build up ceases.

38 Special 158gn SWC for ICORE Power Factor - 760 fps required to make PF. I use MoBuCo soft cast slug (BHN 12). Again, an extremely accurate round. They run about 790 fps (two recipes actually - using W231 and Nitro 100). As with the above round, leading is similar after about 200 rounds.

38 Special +P 158gn SWC for recoil practice. Runs about 920 fps. I use a MoBuCo hard cast slug (BHN 18) for the application. A really fun shooter. Doesn't lead the barrel quite as much as the above two loads.

357 Magnum. 158gn SWC for magnum level practice. Runs 1100 fps. Uses the same MoBuCo hard cast as above. A great shooting round, but does lead the barrel after only a few dozen rounds.

45 ACP. 200gn SWC. For target shooting. Runs 778 fps and is extremely accurate. Hardly leads the barrel at all. Bullet used varies - as long as it's a .452" slug.

Those are all my regular production lead rounds, and their purpose. I've got a few other ideas dancing around in my head - maybe some day.

As for other calibers:

I'll shoot 44 Specials with lead - but never settled on a recipe I liked (consistency issues, not leading) and haven't worked on a recipe as of lately. I rarely shoot my one 44 (Mag) gun. My next attempt will be with a 240gn SWC and probably Bullseye powder.

9mm: I run into leading problems. Although I've had decent luck with 147gn slugs and I'm going to pursue this one further. I think .356" is too small. Need to find some .357's. But. . . I rarely shoot 9mm and I have a lot of factory ammo.

10mm: Won't even consider it. (And I don't own a .40 cal)

That's just a brief rundown of my loading experience and lead. In short, I love shooting lead. It's accurate. Very accurate. When I'm shooting in a match, I'm packing lead. But I also have a realistic expectation of its high velocity performance. Like I said: Lead leads. It just does. I live with it. Some days I'm not in the mood to scrub lead out from my barrel; so I reach for my plated rounds that day - it happens. (I have plated equivalent workups for all the above-mentioned recipes)

[GP100man]

Nick hit on some good points. But I gotta ask which caliber ?? hand gun or rifle?

Well in either one there`s 2 kinds of leading . 1st is gas cutting caused by the hot gases having a path to blow by the base of the bullet. Globes of lead can be smeared the length of the barrel in just a few shots if the rite conditions exist!!
2nd is skidding or overspeeding your alloys ability to grab the lands & start spinning the bullet. This type can start leaving slivers at the first shot & leed to gas cutting & is over looked/missed very easily if the bore isn't inspected often.

On new loads ,especially when in the upper pressures, I check the bore after each shot (be sure to tell range officer what you`re doing/your intensions & be sure to adhere to range rules on firearm inspection/repair.) Some ranges require you to go to "safe area" for firearm inspection or maintence.

Now , as we know firearms are as individual as we ourselves are & problems shooting lead can come easily & some are fixed easily ,some not so !

What may work with no issues in "my" firearm may not neccasarily work in any other.

Some things to do before switching to lead in a firearm .

Clean it from all traces of copper (some claim copper helps smooth a bores ruff spots, thus leaving it in place) I clean mine then use JB bore paste . Let me say I like using a jag & patches for final kleening of the bore , it has better "feel" of the smoothness of the bore. a snug fit is a must but not so tite ya have a fight with it .

Measurements of chamber throats & bore are a very good numbers to know. But trial & error is fun sometimes , if ya like scrubbing bores . I don`t !

But this is how I learned & maybe keep some from the fate I endured.

Thank goodness for choreboy copper scrub pads !!

& Thank GOD for the good people on CastBoolits.com !!!!

GP

[noylj]

For this discussion, let's assume the bullets are appropriately sized for the barrel, and weapon. With cast, it seems the process is the same except for barrel leading. Or is it all about leading?

First, slug the barrel. The bullet must be AT LEAST 0.001" over actual groove diameter.

Second, leading is not that big an issue. I have never had a barrel that was leading lose accuracy until about 100 rounds had been fired.

Three, where leading occurs will tell you what the problem is. In so many cases, the problem is the bullet is too small for that gun or the alloy is too hard. Almost all commercial cast bullets are WAY too hard and should be about 0.002" over groove diameter.
A clue to what is causing the leading is where the leading first begins to appear.
If it appears near the chamber, chances are that bullet diameter or hardness are the cause. A diameter too small or an alloy too hard will allow high pressure gas to leak past the bullet, which erodes the bullet and leaves leading near the chamber.
If the leading first appears on the leading edge of the rifling (if you imagine the bullet being pushed through the barrel, you will note that one edge of the rifling does most of the work of imparting a spin to the bullet. This is the edge you see when you look through the barrel from the breech end), the bullet might be too soft or the velocity too high.
If the leading appears in the second (front) half of the barrel, the bullet is running out of lube.

Four, if you are paranoid, buy coated lead bullets.

Remember, lead bullets were around for centuries before jacketed bullets, so they aren't some unknown quantity.

1. what is the best process for detecting barrel leading? Visual inspection, running a patch feeling for the lead fouling, or combination of both?

Get a light that shines down the barrel in inspect it. Otherwise, just hold it up to the light. You'll know it when you see it. When you clean the barrel, inspect it. When you first start, only shoot 25 rounds and then go home and inspect the barrel.

2. how often do you check for leading? after each shot, third, fifth?

When you first start, only shoot 25 rounds and then go home and inspect the barrel. Once you know you aren't leading, increase your inspection times. I have fired over 2000 rounds of 200gn L-SWCs through my .45 during IPSC competition decades ago and never inspected the barrel or cleaned it during that time. Barrel was still good after the season. Some barrels lead no matter what, and some seem to never lead, no matter what.

3. how often do you clean the bore? after completion of each load?

I clean the gun and barrel about once a year or so, if I feel like it. I inspect the barrel for new bullets until I know it isn't leading.

4. is it likely you will ever get to excessive pressure signs without first having encountered leading?

Yes. Lead bullets lead for reasons beyond pressure, and pressure is not a prime reason. If the fit is good and the lube is good, they won't lead due to pressure until you reach about 2200 fps. I can "easily" get pressure signs in a 9x19 without any leading in the barrel and my .30-06 and .30-30 don't show any leading.

5. confirm you keep going until you; get leading, experience excessive pressure signs, or reach max load?

I keep going until I reach max pressure signs or I have reached the optimum accuracy point and accuracy is deteriorating (this is 99.9999% of the time). I have not, except in one case, ever tried to load to max and have never needed to (I was running pressure/chronograph testing in the mid '70s with my Browning Hi-Power and found some very interesting things about that specific gun).
Somewhere around 50-55ksi, my cast bullets need to have gas checks to prevent leading.

[oley55]

thanks guys,

my questions where specifically focused on the initial testing of new loads (components) with an increasing charge sequence. A while back I went to the range and started blasting through a bunch of 357 and 44 mag test loads using coated bullets and wasn't watching for leading. That was a mistake as I did get leading (moderate to severe). Since I wasn't watching for it, I have no idea when/where it began.

So I took more than several steps back, did a lot of swaging and measuring, and then some fire lapping. So I am ready to begin again.

Except this time, I want to be on top of spotting/identifying the first signs of detrimental leading.


Just for FYI and hoping to not get off in the weeds I will be loading cast for .38/.357 (4" Ruger Speed-Six, 2" S&W J, Rossi 24" lever gun) and 44 mag (7.5" Ruger RH and 8" Dan Wesson).

For bullets on hand:

hard cast naked (16 BHN?) 160 gr, .3577" SWC. (will pan lube using Ben's Red formula)
SNS casting, Hi-Tek coated 16-17 BHN, .358", 158gr, RNFP.
SNS casting, Hi-Tek coated 16-17 BHN, .430" 200gr, RNFP.

I have nothing on hand for the 44mag Ruger RedHawk. Cylinder throats are .4326" and the mostly obstruction free barrel is .4303-.4304". So it's way back burner for now.

[Mike / Tx]

I'll throw in one more time,

When I am working up loads for my revolvers, depending on where I am shooting or how much time I think I might have, I will load up 5 rounds at each change of powder weight from lowest to highest.

I check the barrel after each successive round, as I have had several leading after 4 shots which could have been prevented had I checked sooner.


I normally just ease the cylinder out to the side and use a clean patch against the frame so that it will catch some light and illuminate the bore. this is harder with a single action but can and should still be checked.

Once I know things are good with that level I move up to the next level, and repeat. I'm looking mainly for accuracy out of the loads but at the same time I need to know if I am exceeding the threshold of the alloy or lube. Usually a good rule of thumb is the alloy or size issues will show up in the first inch or so of the bore just ahead of the forcing cone, and lube issues will show in the last two inches give or take.

If everything is good with both the alloy and the load you can shoot until you start to see accuracy issues or you feel like it is time to clean things up. With the loads I shoot through my 45 Colt, which are in between standard Colt loads and Ruger only type loads I have shot well over a hundred rounds thought it and it still looks like this,


To be totally honest I don't even know how many rounds I put through it before it got real dirty after hunting one weekend and finally cleaned it up.

Granted there is a little bit showing along the edges of the lands, but this is normal and with the naked eye is hardly seen. It shows up great here with the lighted borescope and some magnification through.

Like most of what noylj posted it is simply a shoot and check ordeal. Start slow and work into it. Once you are confident on how things are going, put some more rounds through it and see how that goes. Most if not all of shooting cast loads is balancing the pressures with the alloy and the lube. Once you find a happy medium you will find that your bore stays pretty clean with only a little powder and lube residue that will easily come out with a few passes of a tight patch or a quick brushing with a bore brush.

[oley55]

thanks all, but one more thing to consider.

Not that I would be shooting fast enough while conducting load accuracy development, I recall reading a post a while back in which the poster explained he had guns which never leaded, that is until/unless rapid firing through an already hot barrel. (if I recall correctly)

I'm having difficulty imagining myself (not being Jerry M.) shooting a revolver or lever gun fast enough and long enough for the barrel to start collecting lead because of heat.

Can I presume the hot barrel issue would be mostly restricted to semi-autos?

[hartcreek]

You should know whar ASSUMING gets you. I use a Lee 240 grainn SWCGC mold to make bullets for my 624 and my IJ Buntline. For the Buntline I am using 22.7 grains of 296 and getting no leading using my tumble lubed gaschecked bullets. I am splitting cases but some of my cases are approaching fifty so I am just replacing the split cases. When my barrel gets to hot I just rest for a bit but it is plenty easy to overheat a revolver.

[skizzums]

I think that smoothness of the bore/rifling has to come into play. I have one revolver, no matter how big I size the bullet, I get leading that I don't with the same alloy/lube running even faster in other guns. I have slugged the bore and tried many different combo's, it just leads, period. it's a snubbie and it's easy to clean, so I just don't worry about much anymore. it's a cheap gun and I can only assume that it has rougher steel than the others. I have since started powdercoating and it really makes casting simple, the bullets don't need to be perfect size and the alloy barely matters, really took a lot of the work out of it, but also some of the fun. before PC, I had a hard time getting bullets over 1150 or so to not lead, but I have never been vigilant about finding perfect alloys, and probably could do it better. but I just generally stay under 1100fps and my .357/38's and 9mm's do just fine. I mix 50% pure with 50% wheelweight and add a couple ounces of tin, that's about as technical as I get anymore. although slight, I would get some level of leading even going slow, but it wouldn't be bad enough to even care by 250 rounds. I have gotten into the happen of running a snake though every hundred or so.

[Mike / Tx]

Barrel and chamber heat can also be a by product of the particular powder your using as well.

What leading you get from running hot is usually from the heat absorbed by the case, which can also be from ambient temps, having an effect on the lube prior to or as the bullet is fired into a hot barrel. Some lubes flow at a low temp and can cause issues in hot weather. Same can be said in cold weather as well. Not to the hot melting part, but some lubes do better in colder weather some in hotter weather. It is simply a balancing act.

There are plenty who have a summer and winter lube for hunting or shooting in extreme temp swings. Around my little part of the woods, I haven't seen an issue "yet" that I am aware of. I haven't hunted in temps lower than 30 nor do I shoot in temps much over 100. In between these though I have used the 45/45/10 blend of Alox in several revolvers with no issues and also the Carnuba Red in others with no issues. When I did most of my work ups it was in the mid 80's to upper 90's so I am hopeful that these two lubes will do fine in whatever I every find myself shooting in. I have left loaded rounds in the truck during summer through the week to see if they were effected and haven't had an issue yet to date. So I am confident these two will work for my loads anyway.

[stubbicatt]

There are many factors to consider in loading cast bullets. If one purchases commercially cast bullets, one pretty much gets what one gets as far as alloy, hardness, diameters, and lubes. If he is casting his own bullets, mould design and lube can make a difference. I have found that the harder, high temperature lubes preferred by commercial casters may not be the best choice.

Deeper grooves, or taller lands, seem to work better with cast bullets than do the shallower lands and grooves in my experience.

In the case of a 357 magnum with hand cast bullets I searched for a bullet with a really large grease groove, and I used a home made lube consisting of pure yellow beeswax, vegetable shortening, a dollop of olive oil and a bit of vegetable oil. It worked well with black powder cartridges also. The resulting lube was fairly soft.

Casting from wheelweights and using my lube in a Marlin lever action I had zero leading that I could detect. Too the bore was nice and slippery after shooting, and shiny from the grease, and cleaning was a breeze, no brushing needed. It is my belief that the larger grease groove carried the lube the length of the barrel, whereas commercial cast bullets of the same diameter would often leave lead streaking the length of the tube.

YMMV

[oley55]

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