Ok, I've been trying to work up a cheap lead 357 load for my Marlin 1894-c
the trick is minimizing leading while getting the accuracy.
I've read most of the old post. I am buying a hard cast round/flat point bullet so I assume I should be pushing it pretty hard to seal the barrel. I've tried several H-Universal (6.0 to 6.7gr) but the leading is terrible.
Any suggestions? I have Universal and HS-6 handy right now.

Leading can be caused by several reasons. Remember that all lead bullets lead to a certain extent no matter how good they are. It is just a matter of how much.

Bullets that are too hard can also cause leading as well as those to soft. As you indicated, you are aware that the hard bullets have to be pushed hard enough to obturate (bump up) to create a proper seal. Bullets with beveled bass can also create this problem at certain velocity/pressure combinations since they seem to allow gas flames to shoot past the bases and begin etching the sides of the bullets before a seal is made.

Bullet diameter should be .001 - .002” larger than bore size. At the least, it should match the throat dimensions of your firearm. A .429” bullet is certain to “lead” if fired through a .431” throat and a .430” bore. By matching diameters to throat and bore sizes as well as using the proper alloy hardness, the bullet has the chance to obturate (expand) and form a near perfect seal in the bore. This will vastly reduce chances of leading while increasing accuracy and velocity. A secondary benefit to this match between bullet and throat is that the chambered cartridge will ultimately be held in much better alignment to the bore rather than being a loose or “slip fit” in the chamber.

Lubrication is a long-time subject of dispute among loaders with each seeming to have either their favorite brand or a “secret formula” brewed in the dark of the moon and having “eye of newt” as part of the mix. OK, not quite that bad…but close. Actually, lube will vary by the needs of the cartridge. A bullet intended for sedate speeds from a .45 ACP will require a lube with a lower melting point than one intended for a hot-loaded .44 Magnum. The worst lubes are found on some of the commercially cast bullets. In some cases this lube is so hard that it literally chips out of grooves and fails to melt even at magnum velocities. Fired bullets with these lubes will actually show rifling marks in the lube still left in the grooves! A sign of proper lube blend and consistency is when fired bullets are found without any trace of lube left and a distinct “star” shaped lubrication accumulation appears at the muzzle of your barrel after several shots. This shows that the lube is doing its job and neither running out too soon nor clinging to the bullet without working in the bore.

Location of the lead accumulation can be an important clue to the problem. If leading appears at the beginning of the barrel the bullet may be too soft and is “skidding” on the rifling rather than being gripped. If the leading appears towards the muzzle, your bullets are probably running out of lube too soon…try a different lube.

If leading is still an issue no matter what you try, it may be your barrel, throats or forcing cone. Some barrels are too rough to shoot cast bullets well but do just fine with jacketed. If your chamber throats are tighter than the bore diameter, no matter what you do cast bullets will lead. A good gunsmith can open these throats to the correct diameter to match your bore and will probably help the situation. While you are at it you might want to ask him to re-cut the forcing cone of your barrel to an 11-degree angle…much better for both jacketed and cast bullets. A rough bore is another matter. If not too bad, you can try hand lapping the bore.

Hand lapping isn’t difficult to do and requires little in the line of materials. Using a suitable cleaning rod and a worn out brush of the correct bore size (so it creates a snug but not tight fit), wrap a thin strip of cleaning patch in a spiral manner down the brush without overlapping. Coat the patch with J. B. Bore Paste and pass it back and forth in the bore 5 times without pushing or pulling it all of the way out of the bore. Change the patch strip, re-coat with the paste and do it again. After several applications you will feel that the patch is slipping easier through the bore. Clean the bore well and inspect. If there are no obvious irregularities, try your lead loads through it. It may take a few sessions with the paste, but unless your bore is extremely rough, things should improve. Though often advertised as the cure for all evils, I really can’t recommend fire lapping. We are talking about the use of abrasives being blasted through throats, forcing cones and bores under tremendous pressure. Unless a person is extremely knowledgeable about the hows and whys of fire lapping plus capable of taking a series of very precise measurements, I just can’t see that this is safe or accurate for firearms in the hands of the average shooter.

Good luck to you and stay safe.

What bullet weight are you using and where is the leading? Breach end or muzzle end?

Wow, great info SSL.
Pumpkin, the leading is the first 2 to 3 inches of the bore. I'm buying what they are calling "hard cast". Not sure how hard that is but that's what they say on the label.
thanks for asking.

Leading at the breech (spelled right this time!) is caused by too hard a bullet for the pressure you're generating. Or too low a pressure for the bullet hardness, however you want to look at it. Either way, the bullet isn't "slugging up" to fill the grooves, allowing gas to blow by the base. I saw a lot of that when shooting CAS as they tend to use very mild loads. I'm not sure if a faster powder would help or not but I'd consider trying it.

J-B paste will clean the bore but it isn't polishing it. I have heard of using FLITZ metal polish on a regular patched jag to polish the bore. They said it didn't so much improve accuracy as it made it much easoer to clean. I've tried it myself on a .22 Hornet rifle, just to see. I don't know how much it helped but there was no harm done. I ran it back and forth through the bore about 20 strokes, then cleaned with J-B to make sure to remove any remaining abrasive.

You didn't mention the bullet weight yet...

Pump-slinger, great input. I'm shooting 158gr bullets. I was trying to avoid buying another powder.......best laid plans I guess.
Actually maybe a should try the 6.7gr load again. I shot 15 of each load the other day: 6.0, 6.2, and 6.7....all Hodgdon Universal.
It could be the 6.7gr of Universal might be ok? Or should I just plan on a faster powder?
(side note)--I've "polished" all three of my barrels with J-B following the instructions on the jar.........running the swab in/out 50 times. Don't think it did anything for accuracy but I believe the cleaning is a little easier.
I love my Hornet. Most fun round I have.....you hit everything you aim at even out to 300yds.

Pumpkinslinger - JB does polish a bore...it just takes a fair amount of repetition. I have successfully used it to polish quite a few rifle and handgun bores including an experiment involving a very early Dan Wesson barrel that looked like it had been chisel-plowed rather than rifled. It took many hours of work but resulted in a near-mirror finish. It would have been quicker to cast a series of lead slugs and hand-lap the more traditional way, but I wanted to see just how far the average person could take it without the mess and work of lead-lapping.

Do I advocate treating a severe case of rough bore in this manner? No; polishing to the extent described also resulted in slightly rounded edges on the lands and grooves that would not be desirable with lead bullets. This treatment is for bores that have minor lateral blemishes, scratches and minor pitting. Using the slightly undersized bristle brush allows the compound to be held against the surface but not mashed against it to cause land and groove deformation unless used tot he extreme.

By making sure that the resulting brush/patch slug doesn't leave the bore ensures that the resulting "negative" impression created by the fit stays properly indexed within the rifling for a snug fit to allow the compound to work.

Squirrelbait - One other thing...be sure that you have all traces of any copper fouling or jacket material removed from your bore before using lead bullets. Lead has a strong affinity for copper and will cling to it causing leading in bores that might not otherwise lead.

thanks to SSL and Pump-slinger for taking the time to give me some inputs. I appreciate it.

I only shoot a 200gr LSWC in my .45ACP. (IDPA gun) But I find their info appreciating as well !!!

If your having trouble getting the lead out, try using a penetrating oil/lube/spray of some sort. You’ll be surprised !!!

221...You hit it right on the head. I have had excellent luck using Kroil (available through Brownell's) to remove both lead and copper fouling. It is a "super" penetrating oil that creeps under the fouling allowing it to be pushed out with a snug patch many times. It also leaves a residue that seems to bond with the bore to at least help fouling to stay loose. Just saturate a patch, push it through and wait a few minutes. A nylon bristle brush helps, but usually isn't needed.

Is this anything like WD-40? Sounds a lot more penetrating?

It is a liquid rather than a spray (many sprays use propellants that can actually cause metal etching). And yes, it penetrates far better than WD-40. Its penetration ability is on the order of a couple of microns. Check it out here www.brownells.com/aspx...10&si=True

WD-40 will work, just not as good or as quick !!!

It's what gave me the idea to try a penetrant. We were at a slug shoot and thats all we had to clean the barrel. I forgot the cleaning box that day.

Again I say, Kudos to Dallan and team for this web site.
I don't have Kroil so I'll try some WD tonight. I'll spray some into a container then dip my cleaning patch into it. We'll let her sit for some time and see what happens.
thanks for the inputs.