This is my 9mm Smith revolver and shooting Missouri Bullet company ""coated" lead SWC with a hardness of 18. Since this is a revolver my loads are kinda light with velocity of 850-900fps using powders Titegroup, WST, WSF. The leading is only in the barrel throat, none in the barrel or the cylinder and they are still giving incredible accuracy! Last week I managed to shoot a 91 2-X in both timed and rapid fire.
Causes of revolver throat leading?
- Thread starter Lefty Trigger
- Start date
holstil
Silver $$ Contributor
A fella told me once to make sure I stayed under 850 when shooting lead. Said I wouldn't have much leading to deal with if I did so. I am no expert with lead by any means but I haven't had much of an issue in my pistols with lead. Can't imagine it matters any more or less in a wheel gun. I'm sure has to do with charge and antimony. I picked up a s&w 357 that I plan to shoot laser cast with so I'm all ears.
I was told that lead too soft and not proper lube will cause that problem
That what I was shooting before I switched to the lead. I never came across any bad reviews except people pushing them way too hard. I really like the accuracy and the clean "hole punch" of the SWC bullet, makes scoring targets really easy.
What is the diameter of your coated bullets?
What is the diameter of the cylinder throat, can you push a coated bullet through the cylinder throat?
Is your taper crimp pinching through the bullets coating? A taper crimp is only use the close up the expanded case mouth after seating. Bullet grip is controlled by sizing and expandeing and not the taper crimp.
If the cylinder throat is a smaller diameter than the coated bullet it may be stripping the bullet coating off.
NOTE, sometimes the section of the barrel that screws into the frame becomes smaller in diameter. Some shooters fire lap the barrel to get a tapered bore and remove the reduced diameter where the barrel screws into the frame.
Shoot some plated bullets and see if you still have a leading problem.
Below a 9mm before applying a taper crimp and the case mouth is a larger diameter than the case body.
Below the cartridge after a "slight" taper crimp to streamline the case mouth for proper feeding in a semi-auto. The case is wasp waisted showing the cartridge has plenty of bullet grip.
Below the Lyman type "M" expander insures straight inline seating and less chance of stripping the bullet coating during seating.
With jacketed and plated bullets normally you only bump the case mouth onto section "B" of the expander. With oversized cast bullets you may need to bump the case mouth onto section "C" for proper seating. Normally section "B" of the expander is a few thousandths larger than bullet diameter allowing the bullet to be pushed and started straight into the case.
What is the diameter of the cylinder throat, can you push a coated bullet through the cylinder throat?
Is your taper crimp pinching through the bullets coating? A taper crimp is only use the close up the expanded case mouth after seating. Bullet grip is controlled by sizing and expandeing and not the taper crimp.
If the cylinder throat is a smaller diameter than the coated bullet it may be stripping the bullet coating off.
NOTE, sometimes the section of the barrel that screws into the frame becomes smaller in diameter. Some shooters fire lap the barrel to get a tapered bore and remove the reduced diameter where the barrel screws into the frame.
Shoot some plated bullets and see if you still have a leading problem.
Below a 9mm before applying a taper crimp and the case mouth is a larger diameter than the case body.
Below the cartridge after a "slight" taper crimp to streamline the case mouth for proper feeding in a semi-auto. The case is wasp waisted showing the cartridge has plenty of bullet grip.
Below the Lyman type "M" expander insures straight inline seating and less chance of stripping the bullet coating during seating.
With jacketed and plated bullets normally you only bump the case mouth onto section "B" of the expander. With oversized cast bullets you may need to bump the case mouth onto section "C" for proper seating. Normally section "B" of the expander is a few thousandths larger than bullet diameter allowing the bullet to be pushed and started straight into the case.
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shoot4fun
Gold $$ Contributor
Their website said the bullets are "hard" and that they can be pushed to magnum velocities.
I didn't call those reviews bad did I?
I said, from repots by users, that the OP should expect leading with them.
Furthermore, the forcing cone of that revolver is likely not highly polished and needs some attention.
Lead bullets favor one forcing cone angle (11 degrees), while jacketed bullets favor another (18 degrees), so it could be the angle your forcing cone was cut. And it could be rough and in need of lapping. It is pristine with no copper left from jacketed bullets - right?
Well after speaking with Missouri about the issue it appears that I am not driving them hard enough for the "hardness" of the alloy. Being 18 harness they can be drove hard and fast, up to 1300fps, according to Missouri. My problem is that there is a sweet spot for super accuracy and its around 850-950fps. They suggested a tighter crimp to hold back to build more pressure or have them make me a special build of the 12 hardness bullets, at a two box minimum. The leading is not anything I cant deal with as far as cleaning it out but I would really rather not have to deal with it. I run what I bought and have them custom make me some to try.
JSH
Gold $$ Contributor
Hard hard hard, is what has been preached for years. A hard bullet will tend to skid before grabbing the rifling.
I would bet on the thread choke myself. Either that or a rough forcing cone.
Size is king in my book. Lube and alloy in no particular order.
Once leading starts it very seldom gets better. It will
Just keep stripping off where ever the issue is.
A search should get you all you need to know or don't want to know.
I would not fire lap it myself. If you have a good smith, take a very slight cut off of the shoulder. Even if it doesn't make contact lock tite can be used to hold the barrel clocked right. I have seen this done and the revolver run for years with thousands of rounds run through it with zero problems.
I would bet on the thread choke myself. Either that or a rough forcing cone.
Size is king in my book. Lube and alloy in no particular order.
Once leading starts it very seldom gets better. It will
Just keep stripping off where ever the issue is.
A search should get you all you need to know or don't want to know.
I would not fire lap it myself. If you have a good smith, take a very slight cut off of the shoulder. Even if it doesn't make contact lock tite can be used to hold the barrel clocked right. I have seen this done and the revolver run for years with thousands of rounds run through it with zero problems.
I had similar issues with my Ruger Redhawk .44 mag. until I cut the forcing cone to 11º. Still shoots jacketed bullets very well and the cast bullets are much more consistently accurate. The tool can be rented from 4DRentals.com and it is fairly easy to accomplish. Just let the cutter do the work and don't 'help it'. Ask me how I know.
A couple of issues could be causing the leading. The bullets should be sized .0005 to .001" larger than the throats of the chambers, to provide a good seal and prevent gas cutting which causes leading in the forcing cone. If it's a hard alloy it needs to be driven fast enough to to obturate and seal the bore and stop or reduce gas cutting as well. The lube is important also. Gas cutting seems to be the major culprit causing leading.
I have two .44 caliber revolvers that lead when using cast bullets of .429" diameter, when using bullets sized .430" and preferably .431", leading is almost eliminated. I bought a box of commercial cast bullets (very hard alloy), sized .429" and these lead the barrels of both guns in the forcing cone and the first couple of inches of the barrels. These will be culled, and blended with the next casting sessions.
I have two .44 caliber revolvers that lead when using cast bullets of .429" diameter, when using bullets sized .430" and preferably .431", leading is almost eliminated. I bought a box of commercial cast bullets (very hard alloy), sized .429" and these lead the barrels of both guns in the forcing cone and the first couple of inches of the barrels. These will be culled, and blended with the next casting sessions.
Real leading will destroy accuracy.
If a coating is a cure all for leading, the hardness of the alloy should not matter.
The coating just replaces bullet lube.
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A intact plated or coated bullet that does not have exposed lead should not cause any leading.
What is striping the coating off the bullet and causing the leading.
Are you deburring the inside of the case mouth, a sharp edge can be cutting into the coating.
Do your bullets have a crimping grove or are they flat sided.
Are your throats or forcing cone stripping the coating from your bullets.
What is striping the coating off the bullet and causing the leading.
Are you deburring the inside of the case mouth, a sharp edge can be cutting into the coating.
Do your bullets have a crimping grove or are they flat sided.
Are your throats or forcing cone stripping the coating from your bullets.
Coated Bullets: The future of lead bullets for handloaders?
https://www.ssusa.org/articles/2017/3/7/coated-bullets-the-future-of-lead-bullets-for-handloaders/
Considerations when handloading
The coating is thin and some precautions must be taken during loading to prevent the coating from scraping off. First, be sure the case mouth is sufficiently flared. Poorly flared cases can result in the coating being damaged when the bullet is seated. Second, use a minimal crimp. Like plated bullets, too much crimp can damage the coating. You want the coating to remain intact so it can properly encapsulate the bullet to prevent bare lead from coming in direct contact with the bore to prevent leading.
Donny Miculek from Hi-Performance Bullet Coatings made the following comments with respect to Hi-Tek coated bullets. Miculek used to own Bayou Bullets and sold the company not long ago, and is now concentrating on selling the coatings.
https://www.ssusa.org/articles/2017/3/7/coated-bullets-the-future-of-lead-bullets-for-handloaders/
Considerations when handloading
The coating is thin and some precautions must be taken during loading to prevent the coating from scraping off. First, be sure the case mouth is sufficiently flared. Poorly flared cases can result in the coating being damaged when the bullet is seated. Second, use a minimal crimp. Like plated bullets, too much crimp can damage the coating. You want the coating to remain intact so it can properly encapsulate the bullet to prevent bare lead from coming in direct contact with the bore to prevent leading.
Donny Miculek from Hi-Performance Bullet Coatings made the following comments with respect to Hi-Tek coated bullets. Miculek used to own Bayou Bullets and sold the company not long ago, and is now concentrating on selling the coatings.
- Hi-Tek bullets must be sized properly to the bore of the firearm they are being used in, just like every other lead bullet out there.
- Care must be taken not to remove (scrape) the coating off the bullet as it is being seated.
- If the bore of a firearm is rough due to poor maintenance or poor machining, Hi-Tek will not work as intended.
- Care must also be taken not to undersize the bullet while crimping. This destroys bullet fit and decreases accuracy and increases fouling.
- Sometimes a gun doesn't like a particular bullet/load, and it takes time to find a combo that works, be it cast, coated or jacketed.
- Finally, it is up to the maker of the bullet to apply coatings correctly for best results.
A lot of good points already brought up, Throats need to be .001 over groove dia, and bullets need to be .001 over throat dia. forcing cone needs to be 11 deg.
The speed you are running, the alloy needs to actually be a little softer, about 12-13b.
I need to say that I don't use coated or plated bullets, but I have been casting and shooting lead for 44 years. I have learned to match alloy to velocity and I can drive hard cast gas checked 285gr bullets from my Blackhawk at 1325fps with little to no leading over a 50 shot session. and what little leading I sometimes get comes right out with a strand of copper chore boy wrapped around a bronze brush. I like SPG for lube.
http://castboolits.gunloads.com/
Visit here, and you will learn more than you want to...
The speed you are running, the alloy needs to actually be a little softer, about 12-13b.
I need to say that I don't use coated or plated bullets, but I have been casting and shooting lead for 44 years. I have learned to match alloy to velocity and I can drive hard cast gas checked 285gr bullets from my Blackhawk at 1325fps with little to no leading over a 50 shot session. and what little leading I sometimes get comes right out with a strand of copper chore boy wrapped around a bronze brush. I like SPG for lube.
http://castboolits.gunloads.com/
Visit here, and you will learn more than you want to...
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