Does firing jacketed help remove lead?

Blue Duck357 · October 2, 2001, 11:15 PM

When I first heard about firing a few jacketed bullets after shooting a lot of lead to help clean the barrel it did not make sense. My thought was that this would just put a copper coating on top of the lead making cleaning even harder as most solvents are designed to work best with lead or copper not both. But now I'm reading of a lot of people doing this.

Am I missing something?

**Mike Irwin** · October 3, 2001, 12:01 AM

No, it's an old wives tale, and in certain situations can cause dangerous over pressure.

It may remove SOME of the lead, but what lead is left is pressed even more tightly into the rifling, making it a LOT harder to remove.

The only way to remove lead is with proper cleaning.

blades67 · October 3, 2001, 12:08 AM

It will increase your chances of seeing what a hundgun blowing up in your hand looks like. I know a number of people that shoot jacketed ammo after shooting lead ammo.. I also know a few people that drink and drive. Both of these habits are stupid and may get somebody hurt or killed. I discourage both of these activities, but some people compete for the Darwin Award even after being taught better.

AC · October 3, 2001, 12:15 AM

It will shoot most of it out but isn't the best method. First, if there is leading there is something wrong with your load. This may be unavoidable if you are buying the cast bullets or loaded ammo.

A simpler, easier way to remove leading is to just cut off a patch from a Chore Boy kitchen copper scrubbing pad, wrap it on a worn bore brush and scrape all that lead out in nothing flat. It won't hurt your bore either. I first read about this from Veral Smith several years ago and it works like a charm.

Mark IV Series 80 · October 3, 2001, 12:51 AM

The lead in the barrel is softer than the copper jacket of the bullet. The jacketed bullet sweeps much of the lead away.

The only time I shoot lead these days, is when shooting .38 Special, 148 grain target wadcutters or defensive loads. I always finish my shooting session with at least two cylinders full of jacketed ammo. This makes the bore cleaning much easier. I usually don't shoot more than 200 rounds in a session, so heavy leading is not a problem.

If I were going to shoot a lot of lead bullets in one session, I would shoot a cylinder full of jacketed ammo every 50 rounds, so that the bore would not get leaded-up too badly.

If you shoot lead bullets in your Glock, and then shoot jacketed ammo, you are asking for big problems.

-Mk.IV

JoeHatley · October 3, 2001, 08:21 AM

My 1 hour range session usually consists of 200 rounds cast bullets and about 50 jacketed or plated bullets.

I'm convinced the jacketed "chasers" help shorten my cleanup time. YMMV...

Joe

Chad Young · October 3, 2001, 08:23 AM

Ok, I had to call my gun smith on this question. Shooting jacketed after lead will remove some visible lead, but what it does not remove gets pounded into the rifling under great pressure, virtually "plating" the grooves with lead. This makes it very hard to remove. This can lead to a dangerous pressure situation as the grooves slowly fill up with lead.

In short: DON"T DO IT!

If you do not beleive me, do this: Shoot a box or two of lead rounds, then shoot a box of FMJ behind it. Hook the gun to an Outer's Foul Out kit and watch the lead that comes out after a couple of hours!!

Also, don't shoot lead in polygonal (Glock, H&K) or Micro-Groove (some Marlin) barrels.

rock_jock · October 3, 2001, 10:31 AM

It doesn't make any sense that a jacketed bullet will "sweep" anything away, unless the nose of the bullet is perfectly flat (and preferably, would fill the grooves of the rifling), like a wadcutter shape. The leading conical edge of most bullets, and even a semi-wadcutter, would push the lead up against the bore, where it would be compressed as the main body of the bullet moved over it. And I concur, this would make cleaning more difficult and create dangerous pressure levels.

johnwill · October 3, 2001, 04:52 PM

I'll have to weigh in on the "don't do it" side. It makes no sense that it would remove anything close to all the lead, and it can lead to dangerous chamber pressures.

GeneS · October 3, 2001, 05:34 PM

Shooting a couple of cylinders of Federal Nyclads before cleaning will make the job easier. Does Federal still make Nyclads? I haven't seen any on the dealers' shelves in a while.

**Mike Irwin** · October 3, 2001, 06:46 PM

Nyclads are available, but hard as hell to find.

Jim Keenan · October 3, 2001, 09:03 PM

Those who say a jacketed bullet merely "irons" the lead into the barrel are correct. It will take an awful lot of lead from very badly lubricated bullets to cause a gun to "blow up" though. I think that is also an old wive's tale, and would like to see some real evidence of it happening and the circumstances.

At one time, some people filed the base of a FMJ bullet flat so it had sharp edges, then loaded it backward with a light charge of powder. This supposedly cleaned up the barrel of lead or cupro-nickel jacket fouling. (Try at your own risk - do not use a hollow point or soft point bullet.)

Jim

**Mike Irwin** · October 3, 2001, 09:19 PM

Jim,

Blown up gun? Maybe, maybe not, my bet on maybe only with heavy loads and a truly plugged bore.

Ringed or otherwise distorted bore? Much more likely.

Mark IV Series 80 · October 3, 2001, 09:32 PM

Originally posted by rock_jock:

It doesn't make any sense that a jacketed bullet will "sweep" anything away, unless the nose of the bullet is perfectly flat (and preferably, would fill the grooves of the rifling), like a wadcutter shape. The leading conical edge of most bullets, and even a semi-wadcutter, would push the lead up against the bore, where it would be compressed as the main body of the bullet moved over it. And I concur, this would make cleaning more difficult and create dangerous pressure levels.

Hello rock_jock,

I have some Speer jacketed 148 grain wadcutters, and they do work well to clean most of the lead out of the barrel, but regular, 130 grain FMJ seems to clean just as well.

This question is very easy to answer - Get off the internet and do your own test!

Go to the range and shoot 150 or 200 rounds of lead bullets, then go home and clean your gun, noting the time it takes to clean your bore.

The next time you go to the range, shoot the same number of rounds of the same lead ammo through the same gun and then finish the session by firing 12 to 15 jacketed rounds. Compare the time it takes to clean your bore with the time of the previous session.

You will have your answer.

-Mk.IV

**JohnKSa** · October 4, 2001, 12:24 AM

The Beretta 92 Manual states that you should NEVER fire lead bullets and then follow them with jacketed bullets in their pistols.

I also recall seeing a post on another forum awhile back of a blown up Glock. The owner claimed he had shot one box of lead bullets and then a single jacketed round.

This used to be commonly recommended for revolvers, but I think it's a very bad idea in autopistols since they lack the barrel to cylinder gap which can act as a pressure release valve.

Mark IV Series 80 · October 4, 2001, 05:44 AM

Originally posted by JohnKSa:

The Beretta 92 Manual states that you should NEVER fire lead bullets and then follow them with jacketed bullets in their pistols.

Hi John,

It is a good recommendation to follow the warnings in the owners manual! Most manuals that I have seen do not recommend reloads.

I do not recall a warning about following lead ammo with jacketed ammo in the manual for the S&W revolver or the Colt 1911-type. These are the guns that I have used with this pre-cleaning, lead removal technique.

I would never shoot lead ammo in the Glock!
The danger of shooting lead in the polygonal barrels is well documented.

-Mk.IV

October 4, 2001, 06:55 AM

I never gave this much thought, but it does make one thing clear to me. For this times that I shoot some occasional wadcutters or LRN, I have to remember to clean my guns before I run some good defense ammo through them.

Cheapo · October 4, 2001, 12:41 PM

Anyone ever captured any of those jacketed bullets fired down a leaded bore and examined them for lead buildup on the ogive/bearing surface junction?

Anyone ever done this test in a pistol:

Weigh the barrel alone in a precise scale; then

Fire 150 rounds lead, from a load that produces visible lead deposits; then

Swab the barrel with Break Free (or similar bore-only cleaner, no lead fouling solvent component) followed by a dry patch; then

Weigh the barrel in that same precise scale to document the weight of total lead deposits?

IF you then fire a few jacketed loads through that same barrel and repeat the process, you could even quantify how many micrograms of lead the jacketed bullets remove--if any.

I guess the results would be most reliable if done first with an unconditioned, regularly-cleaned barrel, and then again with the barrel being cleaned with the Outers Foul-Out before the second run.

My guess is that firing jacketed would remove maybe half the lead, but that would be the half that's already easiest to remove anyway.....

Brasso · October 4, 2001, 04:59 PM

I don't know how much lead it will remove, but I err on the side of caution and try to avoid doing it. If you can load your own, you can find a combo that doesn't lead the barrel much at all. I load mostly .44mag. 285gr cast bullets (home made) that do about 1400fps and don't hardly lead the barrel at all. The store bought cast bullets such as Laser Cast are terrible for leading the barrel. I also tried the 100% copper kitchen pads wrapped around an old bore brush, and it will completely clean a badly leaded bore in a matter of seconds, as well as the cylinders. I can recommend it as a very easy, fast, and safe alternative to shooting jacketed rounds on top of lead. I've also found that Birchwood-Casey Bore Scrubber works wonders on removing lead and carbon build up. It also acts as a lubricant and anti-rust agent.

Lance · October 5, 2001, 06:34 AM

I was told by a lady tec. at Ruger in Az. last week to not shoot
Remington Thunderbolts .22's because of lead build-up, and if I did, to follow it with copper jackets to clean out the lead.
I almost bought it, till I read this thread...........

Lance

October 5, 2001, 06:39 AM

Quote:

I was told by a lady tec. at Ruger in Az. last week to not shoot Remington Thunderbolts .22's because of lead build-up, and if I did, to follow it with copper jackets to clean out the lead.

If she can find me some 22LR that has a copper jacket, I would be forever in debt to her. All I have seen in 22LR is Lead Round Nose, Lead Hollowpoint, and Plated Hollowpoints. They can be plated with brass or copper, but they sure aren't jacketed. They would sure be valuable to a lot of people on this board of they existed.

johnwill · October 5, 2001, 08:44 AM

Lance,

I guess that just illustrates how clueless some workers at Ruger really are.

Poodleshooter · October 5, 2001, 03:51 PM

HA! Thunderbolts are one of the most reliable and accurate "economy" .22's in my Rugers.
I answered this question to my satisfacation last night 200rounds of 158gr LSW's loaded with Clays powder followed by 1 round of 158gr FMJ over 17gr of 296. Just before the FMJ, the throat had quite a bit of lead plated onto it. After that shot, 75% of it was gone, with only small amounts clinging in the grooves.

Fisher · October 5, 2001, 04:45 PM

Ok guys, I have a question concerning this topic. If ishooting a jacketed bullet down the tube after several lead bullets is bad. What about lead bullets with gas checks on them ?? Isn't this going to cause the same problems you have described concerning the jacketed bullets ?? Not to mention doing it all in one shot. A lead bullet with copper gas check chaser.

Hal · October 5, 2001, 07:52 PM

Fisher,
Re: Gas checks.
No, using a gas check isn't the same at all. Part of the shooting crowd (myself included) subscibes to the theory that leading is caused mainly by the hot gasses melting the base of the bullet, and not by the friction of the bullet going down the bore. Gas checks protect the lead base of the bullet from the hot gas caused by the burning powder.

FWIW, I started to lean to this idea when I found I could drive swaged (softer than cast lead) bullets(no gas check) faster using a slower burning powder without any leading. I had been using Unique(moderatly fast) to drive a 240 gr swaged .44 at 900-1000fps and had leading so bad it caused the bullet to keyhole. I swithed over to 2400 and was able to drive the same bullet in the same gun over 1200 fps with no problem.

Think of a gas check as kind of a 1/8th jacketed round. I prefer not to use a gas check since I'm deathly afraid it will shed in the barrel. I know, I know the odds are better that I'll win the lottery every week for a year straight, and I'm 100% wrong to think that way. The reason I'm so paranoid about it is because I did shed a half jacketed Speer 240 gr once.(((shudder))) To this day, I have no idea what made me stop and check the barrel before I pulled the trigger on the next round. The round fired, it all felt normal and the bullet hit the target where I aimed.,,but that's OT.

October 2, 2001, 11:15 PM	#1
Blue Duck357 Senior Member Join Date: October 6, 2000 Posts: 1,461	Does firing jacketed help remove lead? When I first heard about firing a few jacketed bullets after shooting a lot of lead to help clean the barrel it did not make sense. My thought was that this would just put a copper coating on top of the lead making cleaning even harder as most solvents are designed to work best with lead or copper not both. But now I'm reading of a lot of people doing this. Am I missing something?

October 3, 2001, 12:01 AM	#2
Mike Irwin Staff Join Date: April 13, 2000 Location: Northern Virginia Posts: 21,167	No, it's an old wives tale, and in certain situations can cause dangerous over pressure. It may remove SOME of the lead, but what lead is left is pressed even more tightly into the rifling, making it a LOT harder to remove. The only way to remove lead is with proper cleaning. __________________ Coworkers. A convenient source of food in a post apocalyptic world.

October 3, 2001, 12:08 AM	#3
blades67 Senior Member Join Date: April 22, 1999 Location: Chandler, Arizona, USA Posts: 6,017	It will increase your chances of seeing what a hundgun blowing up in your hand looks like. I know a number of people that shoot jacketed ammo after shooting lead ammo.. I also know a few people that drink and drive. Both of these habits are stupid and may get somebody hurt or killed. I discourage both of these activities, but some people compete for the Darwin Award even after being taught better. __________________ Guns cause crime like spoons cause Rosie O'Donnell to be fat! I hunt, therefore I am.

October 3, 2001, 08:21 AM	#6
JoeHatley Senior Member Join Date: July 1, 1999 Location: Iowa Posts: 2,137	My 1 hour range session usually consists of 200 rounds cast bullets and about 50 jacketed or plated bullets. I'm convinced the jacketed "chasers" help shorten my cleanup time. YMMV... Joe __________________ Go NRA

October 3, 2001, 08:23 AM	#7
Chad Young Senior Member Join Date: September 20, 1999 Location: Gainesville, FL Posts: 601	Ok, I had to call my gun smith on this question. Shooting jacketed after lead will remove some visible lead, but what it does not remove gets pounded into the rifling under great pressure, virtually "plating" the grooves with lead. This makes it very hard to remove. This can lead to a dangerous pressure situation as the grooves slowly fill up with lead. In short: DON"T DO IT! If you do not beleive me, do this: Shoot a box or two of lead rounds, then shoot a box of FMJ behind it. Hook the gun to an Outer's Foul Out kit and watch the lead that comes out after a couple of hours!! Also, don't shoot lead in polygonal (Glock, H&K) or Micro-Groove (some Marlin) barrels. __________________ Come visit me at www.aboutguns.net

October 3, 2001, 12:15 AM	#4
AC Senior Member Join Date: November 5, 1998 Posts: 268	It will shoot most of it out but isn't the best method. First, if there is leading there is something wrong with your load. This may be unavoidable if you are buying the cast bullets or loaded ammo. A simpler, easier way to remove leading is to just cut off a patch from a Chore Boy kitchen copper scrubbing pad, wrap it on a worn bore brush and scrape all that lead out in nothing flat. It won't hurt your bore either. I first read about this from Veral Smith several years ago and it works like a charm.

October 3, 2001, 12:51 AM	#5
Mark IV Series 80 Senior Member Join Date: April 28, 2001 Posts: 540	The lead in the barrel is softer than the copper jacket of the bullet. The jacketed bullet sweeps much of the lead away. The only time I shoot lead these days, is when shooting .38 Special, 148 grain target wadcutters or defensive loads. I always finish my shooting session with at least two cylinders full of jacketed ammo. This makes the bore cleaning much easier. I usually don't shoot more than 200 rounds in a session, so heavy leading is not a problem. If I were going to shoot a lot of lead bullets in one session, I would shoot a cylinder full of jacketed ammo every 50 rounds, so that the bore would not get leaded-up too badly. If you shoot lead bullets in your Glock, and then shoot jacketed ammo, you are asking for big problems. -Mk.IV

October 3, 2001, 10:31 AM	#8
rock_jock Senior Member Join Date: January 19, 2000 Location: SE Texas Posts: 1,789	It doesn't make any sense that a jacketed bullet will "sweep" anything away, unless the nose of the bullet is perfectly flat (and preferably, would fill the grooves of the rifling), like a wadcutter shape. The leading conical edge of most bullets, and even a semi-wadcutter, would push the lead up against the bore, where it would be compressed as the main body of the bullet moved over it. And I concur, this would make cleaning more difficult and create dangerous pressure levels.

October 3, 2001, 04:52 PM	#9
johnwill Senior Member Join Date: April 6, 2000 Location: PA Posts: 3,459	I'll have to weigh in on the "don't do it" side. It makes no sense that it would remove anything close to all the lead, and it can lead to dangerous chamber pressures.

October 3, 2001, 05:34 PM	#10
GeneS Senior Member Join Date: April 15, 2000 Location: North Carolina, USA Posts: 149	Shooting a couple of cylinders of Federal Nyclads before cleaning will make the job easier. Does Federal still make Nyclads? I haven't seen any on the dealers' shelves in a while.

October 3, 2001, 06:46 PM	#11
Mike Irwin Staff Join Date: April 13, 2000 Location: Northern Virginia Posts: 21,167	Nyclads are available, but hard as hell to find. __________________ Coworkers. A convenient source of food in a post apocalyptic world.

October 3, 2001, 09:03 PM	#12
Jim Keenan Senior Member Join Date: March 17, 1999 Posts: 10,621	Those who say a jacketed bullet merely "irons" the lead into the barrel are correct. It will take an awful lot of lead from very badly lubricated bullets to cause a gun to "blow up" though. I think that is also an old wive's tale, and would like to see some real evidence of it happening and the circumstances. At one time, some people filed the base of a FMJ bullet flat so it had sharp edges, then loaded it backward with a light charge of powder. This supposedly cleaned up the barrel of lead or cupro-nickel jacket fouling. (Try at your own risk - do not use a hollow point or soft point bullet.) Jim __________________ Jim Keenan

October 3, 2001, 09:19 PM	#13
Mike Irwin Staff Join Date: April 13, 2000 Location: Northern Virginia Posts: 21,167	Jim, Blown up gun? Maybe, maybe not, my bet on maybe only with heavy loads and a truly plugged bore. Ringed or otherwise distorted bore? Much more likely. __________________ Coworkers. A convenient source of food in a post apocalyptic world.

October 3, 2001, 09:32 PM	#14
Mark IV Series 80 Senior Member Join Date: April 28, 2001 Posts: 540	Originally posted by rock_jock: It doesn't make any sense that a jacketed bullet will "sweep" anything away, unless the nose of the bullet is perfectly flat (and preferably, would fill the grooves of the rifling), like a wadcutter shape. The leading conical edge of most bullets, and even a semi-wadcutter, would push the lead up against the bore, where it would be compressed as the main body of the bullet moved over it. And I concur, this would make cleaning more difficult and create dangerous pressure levels. Hello rock_jock, I have some Speer jacketed 148 grain wadcutters, and they do work well to clean most of the lead out of the barrel, but regular, 130 grain FMJ seems to clean just as well. This question is very easy to answer - Get off the internet and do your own test! Go to the range and shoot 150 or 200 rounds of lead bullets, then go home and clean your gun, noting the time it takes to clean your bore. The next time you go to the range, shoot the same number of rounds of the same lead ammo through the same gun and then finish the session by firing 12 to 15 jacketed rounds. Compare the time it takes to clean your bore with the time of the previous session. You will have your answer. -Mk.IV

October 4, 2001, 12:24 AM	#15
JohnKSa Staff Join Date: February 12, 2001 Location: DFW Area Posts: 11,691	The Beretta 92 Manual states that you should NEVER fire lead bullets and then follow them with jacketed bullets in their pistols. I also recall seeing a post on another forum awhile back of a blown up Glock. The owner claimed he had shot one box of lead bullets and then a single jacketed round. This used to be commonly recommended for revolvers, but I think it's a very bad idea in autopistols since they lack the barrel to cylinder gap which can act as a pressure release valve.

October 4, 2001, 05:44 AM	#16
Mark IV Series 80 Senior Member Join Date: April 28, 2001 Posts: 540	Originally posted by JohnKSa: The Beretta 92 Manual states that you should NEVER fire lead bullets and then follow them with jacketed bullets in their pistols. Hi John, It is a good recommendation to follow the warnings in the owners manual! Most manuals that I have seen do not recommend reloads. I do not recall a warning about following lead ammo with jacketed ammo in the manual for the S&W revolver or the Colt 1911-type. These are the guns that I have used with this pre-cleaning, lead removal technique. I would never shoot lead ammo in the Glock! The danger of shooting lead in the polygonal barrels is well documented. -Mk.IV

October 4, 2001, 06:55 AM	#17
PreserveFreedom Guest Posts: n/a	I never gave this much thought, but it does make one thing clear to me. For this times that I shoot some occasional wadcutters or LRN, I have to remember to clean my guns before I run some good defense ammo through them.

October 4, 2001, 12:41 PM	#18
Cheapo Senior Member Join Date: November 19, 1998 Posts: 986	Anyone ever captured any of those jacketed bullets fired down a leaded bore and examined them for lead buildup on the ogive/bearing surface junction? Anyone ever done this test in a pistol: Weigh the barrel alone in a precise scale; then Fire 150 rounds lead, from a load that produces visible lead deposits; then Swab the barrel with Break Free (or similar bore-only cleaner, no lead fouling solvent component) followed by a dry patch; then Weigh the barrel in that same precise scale to document the weight of total lead deposits? IF you then fire a few jacketed loads through that same barrel and repeat the process, you could even quantify how many micrograms of lead the jacketed bullets remove--if any. I guess the results would be most reliable if done first with an unconditioned, regularly-cleaned barrel, and then again with the barrel being cleaned with the Outers Foul-Out before the second run. My guess is that firing jacketed would remove maybe half the lead, but that would be the half that's already easiest to remove anyway..... __________________ Let us never forget that the only legitimate source of government power is the citizens. If WE cannot exercise a certain power, we cannot grant it to the state.

October 4, 2001, 04:59 PM	#19
Brasso Senior Member Join Date: October 28, 1999 Location: AL Posts: 468	I don't know how much lead it will remove, but I err on the side of caution and try to avoid doing it. If you can load your own, you can find a combo that doesn't lead the barrel much at all. I load mostly .44mag. 285gr cast bullets (home made) that do about 1400fps and don't hardly lead the barrel at all. The store bought cast bullets such as Laser Cast are terrible for leading the barrel. I also tried the 100% copper kitchen pads wrapped around an old bore brush, and it will completely clean a badly leaded bore in a matter of seconds, as well as the cylinders. I can recommend it as a very easy, fast, and safe alternative to shooting jacketed rounds on top of lead. I've also found that Birchwood-Casey Bore Scrubber works wonders on removing lead and carbon build up. It also acts as a lubricant and anti-rust agent.

October 5, 2001, 06:34 AM	#20
Lance Member Join Date: November 2, 2000 Location: Jackson, Michigan Posts: 77	Ruger recommends it I was told by a lady tec. at Ruger in Az. last week to not shoot Remington Thunderbolts .22's because of lead build-up, and if I did, to follow it with copper jackets to clean out the lead. I almost bought it, till I read this thread........... Lance __________________ "Anyone who doesn't belive in the unalienable human rights granted to us by our Creator, and detailed in the U.S. Constitution by our Founding Fathers, ...must be a Communist!" L.C.Shively

October 5, 2001, 08:44 AM	#22
johnwill Senior Member Join Date: April 6, 2000 Location: PA Posts: 3,459	Lance, I guess that just illustrates how clueless some workers at Ruger really are.

October 5, 2001, 03:51 PM	#23
Poodleshooter Senior Member Join Date: August 7, 2000 Location: Floating down the James River in VA Posts: 1,938	HA! Thunderbolts are one of the most reliable and accurate "economy" .22's in my Rugers. I answered this question to my satisfacation last night 200rounds of 158gr LSW's loaded with Clays powder followed by 1 round of 158gr FMJ over 17gr of 296. Just before the FMJ, the throat had quite a bit of lead plated onto it. After that shot, 75% of it was gone, with only small amounts clinging in the grooves.

October 5, 2001, 04:45 PM	#24
Fisher Senior Member Join Date: August 14, 1999 Location: Reynoldsburg, Ohio Posts: 205	Gas checked bullets Ok guys, I have a question concerning this topic. If ishooting a jacketed bullet down the tube after several lead bullets is bad. What about lead bullets with gas checks on them ?? Isn't this going to cause the same problems you have described concerning the jacketed bullets ?? Not to mention doing it all in one shot. A lead bullet with copper gas check chaser. __________________ "A fear of weapons is a sign of retarded sexual and emotional maturity." Sigmund Freud, General Introduction to Psychoanlysis (1952) --------------------------------------------------------------------------------

October 5, 2001, 07:52 PM	#25
Hal Senior Member Join Date: October 9, 1998 Location: Ohio USA Posts: 5,994	Fisher, Re: Gas checks. No, using a gas check isn't the same at all. Part of the shooting crowd (myself included) subscibes to the theory that leading is caused mainly by the hot gasses melting the base of the bullet, and not by the friction of the bullet going down the bore. Gas checks protect the lead base of the bullet from the hot gas caused by the burning powder. FWIW, I started to lean to this idea when I found I could drive swaged (softer than cast lead) bullets(no gas check) faster using a slower burning powder without any leading. I had been using Unique(moderatly fast) to drive a 240 gr swaged .44 at 900-1000fps and had leading so bad it caused the bullet to keyhole. I swithed over to 2400 and was able to drive the same bullet in the same gun over 1200 fps with no problem. Think of a gas check as kind of a 1/8th jacketed round. I prefer not to use a gas check since I'm deathly afraid it will shed in the barrel. I know, I know the odds are better that I'll win the lottery every week for a year straight, and I'm 100% wrong to think that way. The reason I'm so paranoid about it is because I did shed a half jacketed Speer 240 gr once.(((shudder))) To this day, I have no idea what made me stop and check the barrel before I pulled the trigger on the next round. The round fired, it all felt normal and the bullet hit the target where I aimed.,,but that's OT.