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Discussion Starter #1
Over the last couple of years we have had some real good runs on lapping, new bore breakin, etc. The following are a couple of statements I would like your opinion on.
"An Abrasive's cutting power is proportional to the force applied against it. for example, 600 grit abrasive is a polishing compound when used on a cloth buffer and will create a brilliant lustrous finish. On a very yight-fitting patch, it's slightly more abrasive to the bore than jacketed bullets, yet it will remove softer lead, powder and jacket fouling and leave an unbelievably clean, bright finish. The abrasive crystals in J-B bore paste are only about a quarter the size of thise in the LBT compound, making it an ecen finer polishing agent when used on a patch. a patch is flexable, applies relatively little pressure to individual abrasive crystals and slides over imperfections such as pits, scratches, forcing cone tapers, etc., leaving a smooth, rounded surface in its wake.  When those same compounds are used on a lead lap, their cutting power is greatly enhanced. Consequently, the finish they producewill be slightly rough.Futhermore, the lead retains its shape, fitting diameters of the bore, leveling off high spots, but leaving low areas untouched"
And.......
"To improve cast-bullet performance in rough bores, many authorities recommend shooting several hundred jackete-bullet loads through the bore, cleaning frequently to minimize the buildup of copper fouling. because jacket material is abrasive, that approach works fairly well on bores which require only a small amount of smoothing It can remove small constrictions in magnum revolver forcing cones, too. As methods go, however, that one is both expensive and time-consuming. Worst of all, it can't correct severe diamensional variations."
It goes on to say that removing no more that .0001" of the bore is best and to remove as much as .0005" is counter productive.
Best Regards, James
 

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James,

I want your opinion. Am I wasting a lot of time and money doing this shoot and clean break in process. Should I go ahead and slug the barrel and if high spots or irregularities present do a fire lap job. What do you do? I bet there is a post out there somewhere but I haven't been able to find it.

Also if you shoot a gas check bullet does the size still matter as much as far as leading is concerned with high velocity loads?
 

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Discussion Starter #3
Chief...I have to be very careful here not to step on toes and start a controversy run. As of late, I have been re-thinking some past procedures (some of those that are popular today). I happen to believe that a good barrel just doesn't "happen" and there are some things one can due to start with during break-in. Most production barrels come to use pretty raw and with open pores. There are three process used in production barrels....cut, button rifled, and hammer forged. The last process is the most expensive, due to cost of machines. Cut and Button barrels can be spotted by the machine marks running along with the land/grooves. Hammer forge barrels will had little marks across the lands/grooves. These hammer forged barrels are very uniform and skin hard. The little marks you see are not rough marks, but rather impinge marks as the mandrel indexed. These barrels may, or may not have constrictions. Contrary to many shooters today, I still hand lap. My only re-thinking is to what abrasive to use. I go along with the statement in the qouted write up, that mild abrasives become strong under the presure of a lap. It may well be that Flitz, under pressure, becomes a mild abrasive, as does JB paste?<!--emo&???--><img src="http://beartoothbullets.com/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'><!--endemo-->?? Maybe that is why I have had such excellent success with in breaking in barrels. I now use it on a cast lead lap, followed during shooting with it on a patch over a bronze brush, and later on just a tight patch. The higher the bhn of a bullet the more the constrictions hurt.
After I have hand lapped a barrel (or sometimes not on a rifle with less constrictions), I shoot five groups(five rounds) and Flitz the barrel of all lead, copper, or powder residue using a patch on a tight brush. I then shoot 10 rounds and repeat, then the remaining 15 rounds and repeat. This gives 50 rounds. After that I use the procedure on and off after about 25 rounds. This has worked for me. These barrels are mirror bright. I have recently slugged the Marlin 1894P barrel that has be shot 600 rounds, both cast and jacketed and can find maybe .0005" from my first notes on the new barrel from the factory. I now have just begun to use Flitz on a tight patch. I use no acid base solvent, maybe a little Mr Red sometimes. I am sure there are other worthwhile methods, but this one has worked for me since 1979.I am convinced that Flitz and JB paste on a tight patch doesn't have enough abrasive action to remove the metal of the barrel. There are some other ingrediants (?) in Flitz that disolves powder residue. My final thoughts are that one should used what they think is best, but one they have tested over a period of time before posting one against another.  
Best Regards, James
 

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James,

I've got a couple questions. Which of the three barrel types is on my 1894 Marlin. Should I be able to tell with a bore light and compare to your description?

Next, what is a cast lead lap, as far as hand lap. I thought hand lapping was using a rod and abrasive and stroking the barrel for a million strokes. Do you shove a bullet through with a lap compound on it or just use something on a special lapping tool?

Now, what is the difference in accuracy between a properly smoothed and prepared barrel and a just shoot barrel for a 100 yd gun like the 44 mag rifle. I understand that leading will be decreased and ease of cleaning by smoothing the barrel and these things are definitely important to me but not as much with this gun. After I prepare this one it will probably only shoot at game and from poitions for game at cans and such. It will spend little time on the bench unless a problem or question with accuracy arises. The 8 inch paper plate at 100yds from an offhand position will be the standard I will be looking for.
 

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Discussion Starter #5
Chief.....I really hesitate to go into methods of lapping barrels any futher than I have stated. There are very diverse opinions as to which method is best. All have there good and bad points. I make my laps out off a hard cast bullets without lube in the grooves, drilled on a drill press, an cleaning jag epoxied in, and tapped into the muzzle about 3". Then pulled back so about half the bullet  is exposed.Then coated with a mixture of JR1 and Flitz.  6oo grit seems to work well if there are any bad constrictions. Blue steel barrels seem clean up better, and faster than, than stainless. I have never used 600 grit in my Marlin 1894P barrel. It does not lead with BTB bullets and a minimum of copper fouling with XTP's with top end loads.
It is my understang that most, if not all, Marlin Ballard type lands/grooves are now hammer forged barrels. My 1894P is and one could see the little impinge marks 90 degrees to the lands/grooves when it was brand new. I don't know if Marlin has installed the hammer forge equipment or having them done. It is also my understanding the the Micro barrel are button rifled. The quoted statements in my first post were thoase of Veral Smith in  Rifle #114 - "Correcting the Revolver's Critical Dimensioms" November/December 1987. I would suggest all read it. I agree 100% with what he said at that time. I don't know if he later changed his approach?
I think I would shoot the rifle some with both jacketed and hard cast bullets with various load data. Then if not satisfied, use some corrective measures. However, Understand that I only use Marshall's BTB cast bullets and can not tell you how any other would perform.
Yes,In a new super clean barrel with a flashlight shinning into the muzzle end, you should be able to see the marks I have mentioned.
Best regards, James
 

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James, those are wise words!  "Shoot it and see!"  I think that too often we get caught up in the theoretical realm and don't appreciate that some of these changes / modifications will ultimately result in little or no difference in the field.

Having said that.... if I had a barrel that leaded badly or gave poor accuracy, I would definitely lap it (as I have done in the past).  But if it met my requirements from the get-go, why bother?

Chief, hand lapping with a lead slug is probably not for the faint of heart.  It is probably best left to those who have great mechanical ability and have themselves learned the art at the knee of another expert.  You could easily end up over-lapping one part of the barrel and not lapping another part enough.   The advantage of the lapping bullet, when fired through the bore, is that each bullet makes exactly one pass through the bore and should hopefully be cutting about the same.

If you find that the barrel on your gun fouls excessively or is very rough, 20 rounds of fire-lapping bullets will be a quick and easy step in the right direction, and you will still have the option of using other methods later on.

Let us know how the shooting goes.
 

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Discussion Starter #7
When I started this run I was looking for some results and thoughts on abrasives. I didn't want to get into fire lapping vs hand lapping inasmuch as the topic can become argumentive, which is counter productive on the forum. I then went on to answer how I broke in new barrels and put in the quotes from Veral Smith. I also stated that there where pros and cons to both methods, with out getting into specifics. However the door is opened when a statement says that by hand lapping the barrel with not be consistant in dimension....I have not found that to be the case.  There are juat as many qualified people against fire lapping as there are for it. I don't know of any factory that recommends or uses it? I dont know of a barrel maker that recommends it? I know Marshall does. I am inclined to think it's juat as tricky as hand lapping??? There are many qualified people that point out the possibility in fire lapping of overlapping the chamber throats and forcing cones, however I don't know as a fact that happens. Some go so far as to say that the lapping compound is blasted between the barrel and face of the barrel, however I don't know if that is the case either. We run into a lot of "They Say" and I can speak of only what I have found to work. As Smith points out...care must be taken in over-lapping a barrel. I am not against fire-lapping since I don't know for sure whether it's good or bad....but I do know hand lapping and am comfortable with it's milder form of lapping. I do know that leading barrel makers hand lap their barrels. So, I suposed it's up to the firearms owner to decide which method he wants to use. As the fellas say, "Different strokes for different folks" With this all in mind, I prefer you all to argue amongst yourselves. Only time will tell.
Since I know so little about fire-lapping I sure as the devil will not argue the merits of one against the other.
Best Regards, James
 

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James ,
     I would suspect that part of your success in hand lapping is that you use very mild abrasives. I think the people who ruin barrels with hand lapping use the heavier grits (320 or coarser). At least that is what I have picked up in reading about people who have ruined barrels.
        I personally have used JB's and Flitz on a tight patch and have seen good results in terms of fouling reduction. I have also firelapped four barrels with Midway's kit. This also helped reduce fouling and in one case improved accuracy. This sure doesn't make me an expert, but my opinion is this; I will continue to Flitz because it works well as far as I can tell and I am sure it is not as abrasive as lapping. I am still lapping my revolver (a few rounds now and then with testing in between) to see if I can improve it's accuracy, but as a general rule I've cooled off quite a bit on firelapping. I know from experience it can move the throat of your rifling forward! (Though fortunately this didn't badly affect the performance of the rifle.)
          Well, that's my .02.           IDShooter  
 

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Discussion Starter #9
ID...Very logical approach. What I found interesting and what started my post was Veral Smith statements concerning abrasives becomeing more aggressive under pressure, whatever the agent. That got me to thinking. I tend to agree with what he says, when I think of it. In essence, a mild abrasive like JB, or whatever, will remove softer lead and copper fouling with the mild pressure of a tight patch, but becomes much more aggressive under the pressure of a lap.
I think the reader should take this into consideration, whatever the method he decides to use. Better to be safe than sorry. As Veral Smith says in his article.....most of the time .0001" will smooth up a rough barrel and .0005 can be too much. Since there is a chance to ruin a barrel, it appears that the safe course would be to use a finer mild agent (whatever his method) and take more time? And that is the essence of my first post. Another thing that has occured to me...in slugging a barrel. The slug is sized to whatever the constriction is and not what the widest part is. Therefore what appears to be a tight barrel may well be just what the constriction is. So the person must, by feel as he pushes the slug through, tell whether or not that he has a tight barrel or one with constrictions?<!--emo&???--><img src="http://beartoothbullets.com/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'><!--endemo-->??
Best Regards, James
 

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James, some good points.  Either method may work perfectly, either one may result in a ruined barrel.  It all depends on the skill of the user.  Yes I'll tell you right now that you can screw up when firelapping!  It does move the throats forward a little, whether this is significant depends on the gun, intended use, etc.

I did suggest in one of my posts that handlapping would be more likely than firelapping to result in uneven barrel dimensions.  Actually, that is totally false, now that I think about it.  Firelapping will definitely cut more on the beginning (breech) of the barrel than the end (muzzle).  So, handlapping would be the preferred method to making a perfectly straight barrel, assuming the skill of the user is up to the task.  That is why the benchrest crowd leans that direction, I suspect.

But, with revolvers especially, we might want or need to cut more at the breech, where the threads screw into the frame.  So firelapping might be the preferred method in that case, again, depending on skill of the user.

OK... on to abrasives.  Maybe there is hope for this thread to get back on topic!

You are 100% correct that the effect of the abrasive is relative to the pressure applied to it, and also the material that it is applied against.  After all, we sand wood with different grits than we sand metal, and with different techniques and different amouts of pressure.  So it is quite logical that the fouling in a barrel will react to lapping different than the steel of the barrel.

There is so much more here that the eye cannot see.  Things like the geometry of the abrasive grains, whether they are held at a particular angle (as if imbedded in a lapping bullet) or if free to tumble (as if being wiped with a cloth.  An example.... when running a lathe or machine tool, if the angle of the cutting bit is not correct, it will either break the bit or just wear it down in short order.  But if the bit is correct, it can cut for many minutes or hours before becoming dull, even if only slightly harder than the material being cut.

There is so much to this topic that it might take a PhD to explain it all... in the meantime, use what works best for you!


(Edited by MikeG at 9:33 pm on Jan. 28, 2002)


(Edited by MikeG at 9:36 pm on Jan. 28, 2002)
 

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James, I'm curious, have you ever cast a slug in the barrel to hand lap?  I saw this written up by C.E. Harris in one of the gun books, probably Handloader's Digest.  Anyway, just curious.

Hope we haven't beaten the topic to death!
 

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Discussion Starter #12
Mike..You are correct on all points. I think, for the sake of those new forum members, we should at this point be clear
that there is a great difference in breaking in a new barrel and lapping a barrel (whichever method)to get out constrictions, if they exist. The new hammer forged barrels are 10 times more uniform than the old cut barrels, both in smoothness and dimensions. In breaking in a new barrel, we use mild abrasives with little pressure (tight patch on a jag) to clear out all residue so the barrel can iron out. In many, many cases (as you know)that is all that really needs to be done. As Veral Smith pointed out...the JB type pastes work well for this, as does a 50/50 Flitz/JR1. It's only with cast bullets that the constritions really come into play, don't you agree? In my opinion, lapping is a last resort.
Yes, I have poured slugs in the muzzles of both rifles and handguns. I, like Smith's article showed, have even poured them in the rear of revolver barrels, mainly to lap the forcing cone smooth. This is done, of course, with the rod in place from the muzzle of the barrel. The rod is wrapped with Tommy Tape and spun slowly with a hand drill. Here again, I think that is is to be done only in the worst cases. I prefer to use a very hard cast oversize bullet with no lube in the grooves. The grooves holds a supply of the agent. Never letting the lap clear completely out of the  barrel when you add no agent. Again....I think lapping is a last resort, however I think breaking in a new barrel is of prime importance. And again!.....I am not anti fire lapping! I have used my method for 40 years and feel a lot safer with it. That's all. No, I don't think we have beat this run to death...there's a lot of "know how" discussed and new shooters should take note.  
Best Regards, James
 

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Excellent topic, Gentlemen.

I have just aquired a S&W 686 Plus. The gun is stainless steel and has never been fired by me, just at the factory. I have read with interest  about the breaking in of a barrel. I primarily intend to shoot cast lead bullets. What would your recommendations be on how to break in my new barrel to give me many happy years of shooting?

Thank You,

Ray C.
 

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Discussion Starter #14
Ray....I'm going to hit this one since I shoot 686's and then the rest of the fellows can follow up. First of all I have not found the 686's to have the constrictions at the frame that the Ruger's do?<!--emo&???--><img src="http://beartoothbullets.com/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'><!--endemo-->??? May be it's only on the ones I have, Another thing I have found is the the chamber throats are not oversize. I can shoot either cast .357" or .358" cast bullets in mine all day long (and hot with hot loads also)! There has been nothing done to my barrels but breaking then in with LR1/Flitz. The two bullets that I swear by are.....
Marshall's BTB 185 gr FNGC and Contender's OWC. There have been deer, hogs and other "River Pests" killed with these bullets and their performance is far above what most shooters expect. I would just use Flitz and follow the posted procedure first. If that doesn't smooth things out go to JB paste or JR1/Flitz on a tight patch. From what I have seen on the 686's that has been enough for mine. Maybe the rest of the crew had some other suggestions.
Best Regards, James
 

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Mr. Gates,

Thank you for your reply. I really like the way this 686 feels!

I will be going to the range in a day or so, to fire the first rounds. I read your instructions on the break in procedure. I do have one question - All that I am doing is putting some Flitz on a patch, and then using a jag cleaning the barrel after every 7 shots (1 full cylinder), for the first 50 rounds or so,correct?

I truly do appreciate your time and expertise in this matter.

Thank you,

Ray C.
 

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Sixgun, you have the idea.  Scrub it with JB as you put those first few rounds through it, per James' instructions.  Let us know how it goes.  If it doesn't lead after this then you are pretty much home free.

Barrel break in and lapping are definitely two completely different things, and I agree that lapping is the "optional" of the two, depending on how the barrel performs with the intended ammo.
 

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Discussion Starter #17
You got it, Ray! There's is something were forgot to mention......Most factory lead .357's run on the soft side and will lead even a perfect barrel. We are talking about a hard cast bullet like Marshall's. If you are using jacketed bullets, just clean of that copper fouling the same way. It should be remembered the evena perfect barrel will have some traces of copper at the junction of the lands and grooves. What do you think< Mike?
Best Regards, James
 

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Some years ago, I used JB paste in the lube grooves of some cast bullets I had in a S/S RSBH 44 mag that was new at the time. I fired about 50 of them this way over a light charge of fast powder.

This effectively "seasoned" the bore to a nice slick/shiney finish. I doubt very much metal was actually lapped away but more like polished instead.

While this is not bore lapping in a sense it could be thought of as an intermediate step between barrel break in and full blown fire lapping.

I too am a little timid with the full blown lapping route myself but that is just my preference and is not meant to disparage firelapping in general.

I've wanted to try it with Flitz instead of JB one day but am still thinking about it.

Regards
 

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Thank you for all the replys and sound advice.

I went to the range and test fired my 686 tonight. I ran 6 cylinders full of assorted handloads, Flitzing between each cylinder. The barrel is now bright and shiney! Now I'll just have to see how it does with lead. The loads I was using had Rainier copper plated bullets.

This worked like a charm! My new pin gun is now "barrel seasoned", now I just have to function test for a couple of hundred rounds!

Thanks again,

Ray C.
 
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