I recently bought myself a brand new S&W Model 29 "Classic" revolver, the gun shoots very well...when I don't flinch like a ninny, but with maximum loads it leads at the last inch of the barrel. I'm using the Lee 240gr SWC TL mold, and a max charge of 2400, and a commercial Canadian clear powder coat. In my Model 27 "Classic", with conventional groove, cast 158 bullets, I get no leading at all, even with max loads. I understand that the powder coating acts as a lube, and a heat shield, and that leading at the muzzle is a sign of not having enough lube on the bullets. How can I correct this? The bullets as cast are .429-430, after two coats of powder they are all .431-.432. Having asked, I don't intend to continue firing maximum charges in this thing, I've read that best accuracy is around the 18-19gr mark, and for general shooting I think I'll load closer to .44 Special velocities.

I can’t give any advice about coated bullets. Sorry for that. I will say it’s unusual to find leading only in the last inch or so of the barrel. When my 44s lead it is usually the full length of the barrel and most pronounced in the area from the forcing cone to perhaps an inch to and inch and a half downstream from there. This is invariably because the bullets are not sized properly.

My thought is to switch to a regular cast bullet sized according to the exit bores of your cylinder or a tiny bit bigger. If this causes leading, I suppose it’s possible you have a barrel with some taper. Perhaps you can get the barrel as clean as possible and then try to judge the barrel with the resistance you feel to a very tight patch as you slide it through the barrel.

I use powder coated slugs in my .45 Colt Model 25-9. I never have a problem with leading so far. Have pushed them a bit, but not to the max. I see no need to do so. If I am going to go for max loads, I will use jacketed bullets.

After I powder coat my slugs I size them. A friend does not size his and says he has no problems with leading. However, I do not know what his loading are as far as velocity goes.

In your 29, I would not shoot a steady diet of full house magnum loads. I had a 29-2 with a 4 inch barrel once upon a time. While I could and did shoot very hot loads through it, most of the time I shot .44 Special loads. If I wanted to beat up a gun (and myself), I used my Ruger Super Blackhawk. The I broke my wrist and that precluded almost all hot loaded handguns.

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USMC 69-93 Combat Pistol Inst.

The Hy Tek coating works very well.

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"He was kinda funny lookin'"

I am a cheap person and I use the Harbor Freight red paint powder coat. It is $6.97 for 16 Oz. 16 Oz. Powder Coat Paint, Red Works for me.

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USMC 69-93 Combat Pistol Inst.

I've never made my own coated bullets, always purchased them. I did have some leading issues with some of the bullets I purchased & the manufacturer later told me it was because they hadn't done a good job in coating them & have since corrected that.

From a prior post of mine:

... decided to try their (Missouri Bullets) .430" 240gr Keith SWC-HT, BHN 18, for use in my 44 Magnums.

... since my initial testing with these in my 629-6 I experienced some issues with these, unlike the 45 Colts I used.

Using some moderate speed powders, Unique, LongShot & BlueDot, loaded between 1000-1100fps, I noticed I was getting leading (not coating build-up) from the muzzle to about 1/3 of the way down the barrel, heavier toward the muzzle tip. Lowering the charge finally eliminated the leading with each powder. I even tried using a taper crimp instead of a roll crimp but that didn't matter.

Cast lead bullets have always leaded at, & just past, the forcing cone in this gun, even using slow powder. These two are obviously opposite.

I did a wipe test with acetone & got a very slight tint of the red coating on the white rag. Could it be the coating wasn't cooked long effort & it's failing to protect it, somewhat like a lubed bullet would if it didn't have enough lube, at the end of the barrel?

.

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Waiting for the break of day

I loaded some lighter loads with 8grs of Universal, no leading from them. Thought about PC and Alox, but I want to avoid that if I'm able. I haven't done a smash test, but fortunately I have a couple bullets with bases improperly filled that I only noticed after I coated, so that's tomorrow's experiment. As for the lead itself, it's hard, can't dent it with my thumbnail hard.

As I understand it, leading at the muzzle is a sign of the bullet, or boolet as the folks over at Cast Boolits call them, running out of lube. That being said, you're probably getting some gas cutting because the bullet is too hard.

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Do it outdoors

Common pc mistakes:

Alloy doesn't matter when it comes to leading. You can use pure/dead soft lead and 50,000+psi loads in a 308w with bullets that were cast out of pure lead and pc'd & have no leading in 22"/25"/26"/30" bbl's.

Under-cured pc will do exactly what you described. Typically you can tell by the color of the finished product. The finished coat will be either dull or lighter in color when it's under-cured. Using clear pc was clearly not a good choice.

Using the wrong expander will cause leading also. This show up with under-cured coating on the bullet and swaged down bullet bases. Any scraping of the lead from bullets not being either started strait or the cases not being belled enough will cause leading.

The smash test only tells you so much. Bullets with under-cured pc will pass the smash test. But when hit with high pressure loads and rifling cutting into it, they will lead the bbl's.

Several years ago I decided to start pc'ing, I saw the "smash" tests being done & that got the wheels turning. Specifically 30cal rifle bullets. A picture of 2 bullets I pc's, left is a 301" 212gr paper patch bullet & right is the lee 230gr blackout bullet.


As you can see the bullets were pc's and ran thru a swaging die that turned them into a completely different design. Recovered bullets from the 100yd berm, was testing alloys for hunting bullets. That 2300fps bullet is a lee 230gr bl cast bullet that was loaded with a 50,000+psi load.

The pc/alloy combo's tested above showed 2 things. It took the bullet to hit something hard for the pc to come off. And that that 230gr bullets alloy is an excellent alloy for a hunting bullet. The others shattered & the 2300fps bullet bent.

More cast 30cal bullets (lee 312-160-tl) to test in the 308w. Traditional cast/lubed vs pc'd.


Typical test target for those bullets pictured above in the 308w being pushed to 2600fps+.


When the pc coating is applied correctly there is no leading.

What happens when the pc is under-cured.

This test was done with bullets that were pc'd on the raggedy edge of being under cured. The bullets were those lee 312-160gr -tl bullets that were pc'd at low temp/short cook time. The bullets were loaded to 2700fps & 30-shots were done in a 30" bbl'd 308w.




The muzzle end of that bbl


The black residue come out with this


If you think your pc is under-cured put a coat of 45/45/10 tumble lube on them. After cleaning the bbl of that 308w I re-testing those same under-cured pc'd bullets with a coat of 45/45/10 tl on them. Took them up to 2800fps+ without issues.

That’s interesting. Good stuff. Thanks for the info, Forrest r.

I have found a set of pin gauges invaluable in helping determine why revolvers lead their barrel and where the problem is . I have recently acquired a S&W 28-2 , 4" barrel . When I dropped a pin gauge down the barrel , it stopped wayyy short of the forcing cone . When the man at the factory had installed the barrel he had to really over torque it to get the front sight indexed to the rear sight . I put 22 rounds of " fire lap " bullets through it this weekend . It just now beginning to show signs of the tight spot being removed . The accuracy has improved quite a bit . Pin gauges also tell you the exact size of the cylinder throats . I bought my set on Amazon for about $100 , It handles sizes from .250--.500 . This isn't just a problem with S&W . I know a guy that laid out major $$$$ for a FA , it had the same problem . He included a picture of the pin gauge stopped short of the forcing cone because of the barrel being over torqued to index it to the rear sight . Shooting cast in revolvers requires we do our part as well . Regards, Paul

Under-cured lube seems to be a good lead. The bullets I cast for my .357 that don't lead at all were baked at a higher temperature than the ones I loaded for the .44. The instructions call for 15 minutes at 340, I think I might go back to 15 minutes at 400, I hadn't read the instructions when I baked the bullets for the .357.

I have PC'd some cast bullets . I used 400 / 15 mins. They worked fine . My BIL (brother in law) is big in the powder coating industry . They use 400-425 on all their jobs . I hope this helps , Regards, Paul

I use either .431" or .432" conventionally lubed bullets in my .44s. I don't know anything about powder coating.

Back off your load one grain at a time and shoot ten shots over a sturdy benchrest at 25 yards, checking for both accuracy and leading. As you guessed, around 18 or 19 grains will probably be a better load and not so hard on you or your gun.

I no longer load any magnum ammo, but used to use 19 / #2400 with a Lyman #429421, about 250 grs. cast of ww alloy.

this is probably a cure issue but another area to look is the LEE TL design.
it really doesn't any solid forward band to engage the rifling.
While PC solved this bullet for me, I cannot be certain it will do the same for you.

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it just needs more voltage

I have same problem shooting Missouri Bullets PC bullet in my Model 69. Bullets are correctly sized for the cylinder throat and lead up the barrel toward the end of the 4.2 inch barrel.
Shooting lead SWC with gas check 230gr. with same load of 9 gr. Unique gives a nice clean bore!
I can also shoot same MB coated bullets with same powder load in my Ruger SBH with 7.5 barrel and it shoots clean as can be.

Checked the M69 for bore restriction at threaded location and there is none....pin gauge slides smoothly all the way thru!

So what could that mystery be??

More than one shooter has complained about leading with the TL designs, lubed or coated. I do not have any issues with PC lead with leading in anything up to almost 2000fps. Check to make sure your loading process isn't sizing the bullet down (LFCD) or just over crimping with some roll crimp dies can undersize the bullet.

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NRA Cert. Inst. IDPA CSO

Yeah. at one point I bored a mold using a modified TL design.
I left a good band of meat at the forward end at the shoulder. This worked exquisitely with old school lube.
TL is more a lube sponge than people may know. Its kinda a good idea really. it just got borked in execution

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it just needs more voltage

I get fine results using TL in 38 special , but it stops there . I would not expect a model 69 to have a tight spot at the frame / barrel junction as it 's a 2 piece design , and torqued at the muzzle . I always ck the cylinder measurement vs the bore of the barrel dimension . I don't want the cylinder throats smaller down sizing my cast bullets . Regards, Paul

Something I hadn't considered...I crimped and seated in one go, upon inspection it seems there has been a little shaving.

And if you over crimp that can also scrape off the coating.

If I want to shoot hot magnum loads I use jacketed bullets.

I made it a standard practice to seat and crimp in separate operations.
It was a marked over all improvement as soon as I adopted the method.

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it just needs more voltage

I think you found the problem.

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Do it outdoors

Some say ecm rifling that smith uses leaves a rougher finish and hence more leading. I have some ecm barrels that do not lead at all while with others I have experienced what the op has with coated bullets. I am not convinced coated bullets lube as well as a good 50/50 Alox on a traditional cast bullet like Lyman 421429. I may try fire lapping on one of mine that leads. Also I like to shoot 4 or 5 hundred jacketed bullets to break things in before I shoot lead. It may help?

I easily run coated lead to 1500fps, no issues. Jacketed just not needed in most handgun applications imo.

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NRA Cert. Inst. IDPA CSO

I just finished shooting , over a 2 day period over 300 bullets in 41 magnum and 45 Colt . Most were powder coated and my loads ran from " mild to wild " . The barrels are very clean and NO leading . I made sure the cylinder throats were the proper size so my cast bullets were not down sized and I had fire lapped the barrels to remove tight spots . Regards, Paul