(Speed) To Lead, or not to lead. That is the question.

[Old Ironsights]

How fast can you push a plain base pure Pb boolit before it leads the barrel?

how about Gas checked?

IIRC base melt/anneal has a good bit to do with it too...

I'm wondering because 99% of my casting is Pure Pb for Muzzlestuffers and I'm wondering just how hard a boolit I really need for the soft-skinned stuff I have the opportunity to shoot with my .357(s)

[BruceB]

Last year during early research for a cast-boolit hunting load, I had my .416 Rigby (Ruger #1) pushing pure-lead RCBS 416-350s at 2000 fps.

There was no visible leading and the accuracy wasn't all that bad at 100 yards, compared to straight-wheelweight boolits of the same design.

However...these were gaschecked, and I strongly suspect that a plain-base pure lead bullet might not tolerate such speeds. I'll also be curious to see if anyone else chimes in with some non-gaschecked figures with pure lead.

[felix]

Bruce, that would be a good experiment. The only fact that enters the equation would be that more the neck/throat is cut in terms of BR dimensions, the less protection would be needed for the boolit base. But, for a hunting gun, dimensions too close to BR spec would be a pisser, or stated another way, profusely pure problem prone. ... felix

[Old Ironsights]

BTW: Can a gas check even be seated without a lubsizer? My current .357 loading arrangement is just a Lee Whack-a-mole...

[steveb]

I see someone is getting prepared for that bullet mold.[smilie=1:

Me too! Im a gettin anxious for sure!:Fire:

[Larry Gibson]

BTW: Can a gas check even be seated without a lubsizer? My current .357 loading arrangement is just a Lee Whack-a-mole...

Lee makes a sizer that seats and crimps on the GC. Like Bruce I have pushed some very soft allyoys to the 2000 fps mark and maintained reasonable hunting accuracy. Leading was not an issue but the bore was cleaned every 10 shots as the test was to see how the bullets shot from a cold clean barrel. Most were just 5 shot groups and then the barrel cleaned. Like Bruce mine also used GCs. I don't shoot near that many at big game anyways. I use Javelina lube. These were in rifles. In rifles I've found accuracy to go south as you approach 1600 fps with PB bullets, even very hard ones. Accuracy goes south before I get leading if Javelina is used.

With respect to the .357;

I have shot PB hard commercial cast upwards of 1300 - 1400 fps without appreciable leading. However, these had the hard wax lube removed and were relubed with Javelina or LLA. It depends a great deal on the actual alloy used and the amount of bevel on the base of most commercial cast bullets. Some commercial cast bullets have sufficient bevel that they allow a GC to be seated on them. I have pushed these ( most recently some 215 gr .44s out of a new Ruger FT .44) to 1450 -1500 fps and maintained excellent accuracy with no leading.

With my own cast bullets in numerous .357s I have pushed lead bullets to 1000 fps, WW or #2 alloy to 1400+ fps and Linotype, 1-16 or 1-10 tin/lead alloy to 1500+ fps without leading. These are plain based (flat base) bullets of appropriate weight and diameter for the revolvers. Six inch plus revolver barrels are required for for these top end velocities. Each revolver or more appropriately, each barrel, is a case unto itself as to leading. Some are smooth and don't lead, some are rough and don't lead, some will lead no matter what you try (few and far between). It just depends. Of course if the bullet is to small a diameter or the the lube is not up to the job leading will occur at some pretty low velocities.

With GC'd cast bullets in the .357 (358156 in particualar) you can drive some pretty soft alloys up to the same 1400-1500 fps without leading (given a reasonable amount of shots). This allows an alloy that will expand for hunting purposes.

Heavy hard cast bullets with large meplats seems to be the rage for hunting these days offering increased "killing" power over the traditional Kieth type SWC. Indeed they do but it really isn't anything new. Kieth and others often commented on the "killing power" of plain WCs at lower velocity than other bullets. Can't remember who (Keith, Skelton, Jordan, Askins or maybe Cooper) commented on the 358495 WC cast hard killing ability being much greater than a comparable SWC at the same velocity. It just so happened that the PD I worked at had a 4 cavity 358495 mould and I cast up a quanity of them in WW. I pushed them to 1400 fps (I've had Oehler chronographs since '75) out of a 6" M28. Accuracy was very good to somewhere around 75 yards then it started going south. this was the same as reported in the articles as they said the faster twist Colts gave better accuracy out to 100 yards but it wasn't much good beyond. I found the WC were real "thumpers" on rabbits, coyotes, rock chucks and a couple wounded deer when compared to SWCs at the same velocity. Penetration was all that was needed and I never questioned that they weren't 'heavy" enough. I haven't shot any of the heavy large meplat bullets that are the vogue these days past 50 yards so i can't quote on how well they hold up velocity or accuracy wise. If you don't shoot beyond 50 yards it's probably not an issue.

I probably got off track there but if I can provide more info on your question let me know.

Larry Gibson

[Old Ironsights]

Thanks Larry. When I say I cast Pure Lead, I mean BHN 5-6 pure. Dead Soft for Roundball pure. No WW or alloys at all.

I know that WW or other lead alloys do fine, but I'm interested in when pure soft lead will start gunking things up.

[Larry Gibson]

Thanks Larry. When I say I cast Pure Lead, I mean BHN 5-6 pure. Dead Soft for Roundball pure. No WW or alloys at all.

I know that WW or other lead alloys do fine, but I'm interested in when pure soft lead will start gunking things up.

For dead soft lead;

Plain based bullet; properly lubed with alox lube (Javelina/LLA) 900 - 1000 fps, maybe a tudge more if the barrel is smooth.

GC'd bullet with alox lube; 1200 fps second or so. You can push them a little faster with perhaps acceptable leading (hunting or self defense) but accuracy may go before leading becomes appreciable. Loss of accuracy will be due to excessive obturaion caused from more acceleration than the alloy can take. How much acceleration the bullet can take is dependant on bullet design. Excessive obturation is indicated by the nose sloughing back unevenly to one side and the bullet collapsing back into the lube grooves unevenly.

Only way for you to know for sure with your .357, your bullet and your lead is to cast some up and test them. What works for my .357 may not in yours and visa versa.

Larry Gibson

[Old Ironsights]

Sounds good.

Thanks!

[D.Mack]

Back in the olden days, when I only had one mold, a plain base, and one alloy, (old lead pipe) I was able to push my velocity up a about 150 fps, by placing a gas check in backwards. This was accomplished by sizing the gas check first in a cut off case with a flared mouth, by just driving it straight through with a dowel rod. To get it to seat straight I had to flare the mouths of my cases a little more than normal, but it alowed me to shoot real 357 velocities with soft lead. DM