fire lapping bore?

[charger 1]

Has anyone done it? I have a ruger that feels rough about 5" away from the chamber. I have been thinking bout lapping it with some 800. with it being closer to chamber than muzzle I've been thinking of making a dozen lead slugs with 20 or so mini grooves.coating them with 800 and let em rip with 10 or so grs of 700X. Its not a roughness you can see,but feel with the bore brush.The muzzle 16" are smooth,its just about 3",4-5" in from chamber.Veral and others recommend it for brand new stuff,ecspecially stainless rugers.Any thoughts?.....PS.The one thing I do like about it is the fact that the chamber end of barrel ends up same or larger than muzzle

[Bass Ackward]

Fire lapping is probably the second most popular topic behind fillers on this board. The popularity comes from emotional responces pro and con.

I just used the search function and found 2 complete pages of fire lapping stuff. everything about the debate to how to. Just type in fire lapping and enjoy.

[charger 1]

Fire lapping is probably the second most popular topic behind fillers on this board. The popularity comes from emotional responces pro and con.

I just used the search function and found 2 complete pages of fire lapping stuff. everything about the debate to how to. Just type in fire lapping and enjoy.

Didnt know it was that popular. Thanks Bass

[BABore]

I've done four guns in the past six months with the Beartooth kits and their directions. In all cases accuracy was improved as well as cleaning ease. I had ER Shaw rebarrel a model 70 to 375 H&H last year. It would shoot Hornady 270 gr bullets into an 1 1/2" group for 5 shots. After lapping and breaking in again the same load grouped into 7/8 inch. I mainly lapped this gun because it copper fouled rather quickly. That too is reduced. I worked up some new loads with Nosler's 260 gr AB bullets. Best groups were with IMR 4350 at 11/16 inch and RL15 at 5/8 inch. I finally shot my first cast bullet out of it this last Sunday. After 3 fouling shots, the first 3 shot group was 3/4 inch at 1,800 fps. I shot 48 rounds out of it with no leading.

I just got done helping my shooting buddy do his uncle's rebarreled 03. It would shoot Remington green box into a 4 inch group and fouled terrible. After 24 lapping rounds and 100 strokes with a coated bob, it grouped the same load into 1 1/2 inches. We still have some bedding issues, but I call that a vast improvement.

My other guns have similar sucess stories. I was kind of skeptical at first, but now have a lot of confidence in Beartooth's kits. Any new gun I get will get lapped. If you need more evidence post your question on Marlinowner's and Beartooth forums. Lots of people there that have had first hand experience. From what I understand, LBT's kit and method are similar to Beartooth's. I would avoid any method that uses jacketed bullets or high velocity.

[charger 1]

Today I poured a dozen of those 500+ grain bore ride 45's out of pure lead. Brought them to my lathe and doubled the grooves. Rolled them in 800grit valve compound. Burped them out with 7 grs of 700x. Cleaned the bore then tried the bore brush down it and could not feel any roughness like before. So I'll try it like that for now

[BABore]

According to Marshall Stanton theories on fire lapping the ideal bullet hardness is 11-12 Bhn. In otherwords ACWW's. The reason being is if the bullet is too soft the embedded lapping compound gets pushed into the bullet rather than cutting into the barrel. The lapping compound he sells with his kit is 320 grit Clover brand. He devoted a few pages of his manual as to why he only recommended the Clover brand over others. Had to do with how silicon carbide broke down and the grease carrier.

The bullets are rolled between plates to embed them and the grooves are filled with compound. They are then loaded into unsized, primed cases with just enough Red Dot, 700X, etc. to get them out the barrel. I used just a tuft of dacron to hold the powder against the primer. Your looking for 500 to 700 fps max.

Most all of the guns I have done took 24-40 rounds to lap. I examined the tooling marks at the muzzle prior to lapping. When they just started to show some signs of cleaning up I stopped. The theory is the most aggressive lapping begins at the throat and progressively works toward the muzzle. When done correctly you end up with a tapered or choked bore. When firelapping is complete I wrapped a brush with a long strip of old underwear until it was a tight fit in the bore. Yeah, clean ones. The bob was saturated with lapping compound and the bore was given a full 100 strokes, with down and back being one stroke. Lapping compound was added as needed. The barrel will actually get quite warm by the time your done. This step is extremely important to get a good finish. After you clean the bore and look down it you will freak out. It's so shiny and smooth that you don't see the rifling when looking straight down it.

[guninhand]

IMHO it's worth it to get the Beartooth manual on this. There are several ways to screw up, such as lapping with a cast bullet that has a nose riding component, getting lapping compound where it's not supposed to go, not using the right grit, etc. He also mentions that Ruger stainless steel is particularly tough.

[charger 1]

IMHO it's worth it to get the Beartooth manual on this. There are several ways to screw up, such as lapping with a cast bullet that has a nose riding component, getting lapping compound where it's not supposed to go, not using the right grit, etc. He also mentions that Ruger stainless steel is particularly tough.

Sometimes there are all the ways retailers tell you that you can screw up. Sometimes not quite all the ways. Sometimes absolutely none of them. In fact in some cases you can do better than them. I think its part of a crazy money making scheme or something they start into business with. Have you ever noticed this phenomenom or is it just me????

[BABore]

Yes. This phenomenom is similar to seeking advise and then listening with ones mouth open. :roll:

[charger 1]

Yes. This phenomenom is similar to seeking advise and then listening with ones mouth open. :roll:

The second one you mention is actually one I prefer. If when giving answers I get a response (liked or not) I find that less rude than talking to a fence post [smilie=p:

[tom barthel]

I used Beartooth's method. I also talked to Marshal Stanton at the number listed on his web site. I even ordered Marshal Stanton's book on the subject. I am very satisfied with my results. I used his bullets after I rolled them in glovers compound. I don't have the compound in front of me but, I think it's impregnated with 320 grit. I remember applying the compound to two flat steel bars and rolling the bullets between the bars to apply the grit to the bullet. I used just enough pistol powder to make the bullet exit the barrel. MY accurracy improved quite a bit. I hope yours does as well.

[guninhand]

Sometimes there are all the ways retailers tell you that you can screw up. Sometimes not quite all the ways. Sometimes absolutely none of them. In fact in some cases you can do better than them. I think its part of a crazy money making scheme or something they start into business with. Have you ever noticed this phenomenom or is it just me????

I'd be surprised if any suppliers in the cast bullet market are hauling in big bucks. The Beartooth Technical Guide is $14, with about 90 pages of info. The only way a person would know if it's worth the $ to them would be to buy it and read it.

As far as doing better goes, I plan on trying firelapping without the fire, i.e puhing the grit laden bullet down the bore with a brass rod using the method described for driving out a stuck lapping bullet. Plus I will use a cutoff empty case in the chamber for centering the rod. I expect that once engraved, the grit bullets should go through without the rod flexing enough to impart unwanted lapping or damage to the lands.

Of course there are products that aren't worth the money. Magnetic bore-sighters and Lee's pistol crimp dies immediately come to mind.

[Dale53]

guninhand;
I know nothing of magnetic bore-sighters, but Lee's Factory Crimp die for pistol and revolvers is a great tool. I just wish that I had it when I was shooting IPSC. It insures that each round will chamber correctly and is done in the regular reloading rotation.

Dale53

[Bass Ackward]

As far as doing better goes, I plan on trying firelapping without the fire, i.e puhing the grit laden bullet down the bore with a brass rod using the method described for driving out a stuck lapping bullet. Plus I will use a cutoff empty case in the chamber for centering the rod. I expect that once engraved, the grit bullets should go through without the rod flexing enough to impart unwanted lapping or damage to the lands.


gunhand,

The most benificial reason to fire lap is how it treats the lands vs hand lapping. Many people think two dimensionally when they think of bore improvement and forget that the most important part is the vertical portion. This is where force is applied to rotate the slug. The best result is for all lands to apply rotational force at the same time with the same stress level on the metal slug . This doesn't happen because a button has hit a tough spot in the steel and the botton slows stretching the part of the barrel behind it like taffy. This elongation results in a change in the angle of the rifling in a small way.

And this is where hand lapping falls short. Because when you hand lap, all you feel is resistance. Two dimensional thinking assumes it is from a diameter constriction. How would you know? So while your git works to correct the twist, it is also cutting a larger diameter there which isn't needed.

With fire lapping, you get as close to perfection as possible. The bullet only cuts that portion of the barrel which is not exactly like it was just before. Once it does, it sizes down or deforms from the bad spot, and it quits cutting the rest of the way through the barrel allowing the next bullet to have a pass at it.

So what really happens with hand lapping is that you get a smooth internal finish. The slug simply followed the imperfections that were there and ironed those in. This probably caused some loss of rifling height. But guess what? When you start shooing bullets, they will fire lap for you again anyway. Then you will loose more rifling height until they get things exactly as THEY want it in the first place, not a hand lap or you. Understand?

So hand lapping can make things no better than before you started, or you can really ruin a barrel for cast if you opened the barrel enough at that percieved constriction that gas can now pass the slug.

[Bret4207]

My #1 rule with lapping is to know when to STOP! If 25 rounds will fix it, it doesn't follow that 50 or 500 will be better. It's a simple thing, but it can be overdone. Fire lapping with cast and condom has worked for me.

[David R]

I firelapped a S&W 38 with Napa valve grinding compound. TOO COURSE. It worked and the gun shoots great now with no leading. The constriction from where the barrel was pressed in is also gone. It took about 350 J boolits to smooze out what the grit had done to the barrel and forcing cone. I only fired 12 shots of lead boolits lubed with the abrasive. At first the forcing cone looked like I had sand blasted it.

David

[guninhand]

Bass Ackward,

The point you are making isn't quite catching on in my mind. For pushing my lapping bullet, which is no different than a bullet one would use for firelapping, I will have a small self-tapping screw screwed into the center of the pushing end of the brass rod, and the head of this screw ground to a sharp needle point. This tip digs into the center of the base of the firelapping bullet and acts as a support point keeping the rod from touching the sides of the barrel. The Stanton guide mentions this as the way to drive out a stuck bullet.

I'm assuming that then pushing the grit bullet down the bore, the bullet will behave just as if it came from a charged case, except for going slower, and I won't have the problem of grit getting blown off the grit bullet.

I'm assuming that the lands will impart rotation to the grit bullet just as if it had been fired and likewise, when the grit bullet is sized down by passing an imperfection in the bore, stays sized down, just as if it had been fired.

Because this way a grit bullet isn't hanging in air like a fired bullet, but has some resistance to rotation due to its being spiked at the base, I don't perceive that small resistance to be enough to change in any significant way the performance of the rod pushed grit bullet versus the gas pushed grit bullet.

The only problem I see is making sure no grit gets into the chamber as I get the to-be-pushed-by-a-rod grit bullet started down the bore. Unlike laps that go back and forth, these grit bullets are one way only, just like fire lapping bullets.

[Bass Ackward]

Guninhand,

Yes. My writting is often lacking. I am not faulting your procedure, only the lap itself.

Did you read the article I posted about Barrel Quality?

A lot of people think that I am big on lapping or fire lapping. I am not. Only in cases where it is demonstrated that it is necessary. Then I have a basic principal. If you need to improve bore finish lap. If you think you need to change barrel dimension or twist rate change, then fire lap. Even Shilen will tell you that the difference between the lower grade and the target selects is only 50 shots.

Since we can't "see" the bad spot to know if it is a constriction, or a high land from the button twisting, or twist rate variance without the aid of expensive equipment, the only way I have to correct that point is with a bullet. Once corrected to that bullets satisfaction, it is for all intents and purposes perfect. That is my point.

Anytime you put a bullet down a bore, no matter what material you use, you are fire lapping until what ever resistance is removed. In the end, no matter what method you choose, the bullet has the final say anyway. So why hand lap and risk human error?

But the barrel making article is really informative.

[BABore]

I think a point that BA made, but got lost, is the difference between the hand pushed lapping bullet and firelapping is the sizing down of the lapping slug. As BA stated the push thru lapping slug gets sized down and conforms to the tightest spot in the bore. Once done it's pretty much only lapping to that size, period.

With low velocity, 10-12 Bhn, 320 grit Clover firelapping, each round is at least 0.002" over. You get a full sized lapping slug with each round fired. That single defining constriction in your bore doesn't dictate your outcome, it is simply removed. If done correctly, the final ulitmate bore constriction is the muzzle. That's the key to making it work. You really have to watch how that last 1/2 inch of barrel is cleaning up so you end up with a choked bore.

[BOOM BOOM]

HI,
I have heard, not sure it is true, that most rifles/pistols shoot smaller gruops afer 1-200 rounds of j-bullets.
Is this , in a sense a form of fire lapping?
I have been told these 1st 1-200 rounds basicly remove birrs & imperfections.
If this is true why not just shoot & have fun.

[Bret4207]

You won't hurt a barrel firing several hundred condom loads before you start accuracy work with cast. But, you can look forward to some boring, hours long cleaning sessions trying to get all the jacket fouling out. Also, if it's a real burner, like a 22-250 that you want ot use for cast, the hot loads tend to errorode the throat and roughen it. It may matter, it may not. I've hand lapped a lot of barrels and I think fire lapping is just as good or better except in weird circumstances where you want to hit one spot and you know exactly where it is. A rust spot for example. Otherwise both methods get you to more or less the same place given due care and knowledge.

[Bucks Owin]

HI,
I have heard, not sure it is true, that most rifles/pistols shoot smaller gruops afer 1-200 rounds of j-bullets.
Is this , in a sense a form of fire lapping?
I have been told these 1st 1-200 rounds basicly remove birrs & imperfections.
If this is true why not just shoot & have fun.

I bought a 46 yr old Ruger .44 that was so copper fouled from cleaning neglect that it took me a couple hours to get the bore clean again. At that point I could plainly see (without magnification) machining marks both linear and radial and the bore had a tendency to lead with CBs. Another hour of polishing with JB bore paste knocked the rough edge off the machine marks. Even though they are still plainly visible, the gun no longer leads at the drop of a hat....

If 46 yrs worth of J boolits didn't smooth those machine marks, I don't see how 200 rds could do it! Maybe it depends how severe the "imperfections" are....

Just my experience,

Dennis

[felix]

Before several years ago, most if not all ruger pistols had barrels made of 4140. It will take abrasive materials to knock off tooling marks, and copper jackets won't do the job. Too much of a difference in materials. But, high antimony, low tin, boolits will smooth that barrel out in time. Actually, longer than you think it should. The newer barrel steels ruger uses are not as hard, but are tougher. Talking especially the 454, 480 guns. ... felix

[Bucks Owin]

Interesting!

Thanks Felix,

Dennis :Fire:

[klausg]

Bucks- my experience with j-bullets & smoothing a bore, basically ran along the 'break-in' as described in the Barnes manual; IIRC you shoot 30 rounds, 10 singles and 10 doubles; with thorough cleaning between each string. Felix is quite obviously a smart guy, and if he says they were made of harder steel I believe him. But from your description, it also sounds like the former owner never cleaned the copper out and it's difficult for a j-bullet to smooth anything out of the steel when it's riding on a layer of copper. Just another way to look at it, FWIW, I'm going back to my corner now

-Klaus

[felix]

Klaus, sooner or later, high antimony, low tin boolits will take out the copper too. Best to get the gun ready up front for lead like everyone says, by getting rid of the copper and burnishing the barrel first with very high speed condoms. This is so your interest in the gun's accuracy will remain high when it comes time for normal lead boolits. Remember, though, that antimony crystals have very sharp edges like the metalic wool. ... felix

[Bucks Owin]

Bucks- my experience with j-bullets & smoothing a bore, basically ran along the 'break-in' as described in the Barnes manual; IIRC you shoot 30 rounds, 10 singles and 10 doubles; with thorough cleaning between each string. Felix is quite obviously a smart guy, and if he says they were made of harder steel I believe him. But from your description, it also sounds like the former owner never cleaned the copper out and it's difficult for a j-bullet to smooth anything out of the steel when it's riding on a layer of copper. Just another way to look at it, FWIW, I'm going back to my corner now

-Klaus

Well, in my case, the previous owner had LOTS of copper fouling caught up in the rough machine marks and just kept on shooting.....(maybe for 46 years!?!) :roll:
Once I got down TO the bore I was able to smooth it up enough with JB.....

That's my story anyway... [smilie=1:

Dennis

[JackOfAllTrades]

Before several years ago, most if not all ruger pistols had barrels made of 4140. The newer barrel steels ruger uses are not as hard, but are tougher. Talking especially the 454, 480 guns. ... felix


You confuse me with the 'not harder, but tougher' statement.

-Steve

[felix]

Steve, the term 'tough' means being able to bounce back without PERMANENT deformation. The term 'non-brittle' or 'soft' means being able to REMAIN deformed. The term 'hard' means the RATE of shape change.

It is difficult to QUAntIFY these terms, but it is easy to QUAlIFY them by examples. For example, you want a car bumber to be SOFT and TOUGH. You want frames for eye glasses to be HARD and TOUGH. You want a gun barrel to be harder and tougher than bullets/boolits.

felix