"On an old one, it's more common than not. Can still shoot well for a number of shots, but abrasion is a leading factor that nearly nothing we can do can fully cure"

Quite to the contrary-- this is one of the simplest conditions to cure. Polishing the bore smooth is quite easy-- using JB paste or similar on a tight cloth patch wrapped on an old, undersized brush.

I've developed a technique fire lapping a bore with a mild abrasive to make them shine. Simple and effective-- the old bores often shooten cast the best due to a gradual taper worn on the leade.

"On an old one, it's more common than not. Can still shoot well for a number of shots, but abrasion is a leading factor that nearly nothing we can do can fully cure"

Quite to the contrary-- this is one of the simplest conditions to cure. Polishing the bore smooth is quite easy-- using JB paste or similar on a tight cloth patch wrapped on an old, undersized brush.


While the polishing compound applied to a cloth patch on an undersized bore-brush is great for polishing, it won't do a thing to alleviate the constricted conditions in a barrel caused from such things as dovetailed sights, dovetailed forend hangers, rollstamp engraving and threaded muzzle-brakes. Often times, if you'll take critical measurements when slugging a barrel, you'll find sometimes up to .003" constriction in a barrel in these areas. As such, when shooting cast bullets, is as though you're putting the bullet through an undersize sizing die, then the bullet is grossly undersize for the remainder of the bore's travel.

It doesn't matter whether a barrel is new or old, and well shot, those constrictions don't just go away from shooting jacketed bullets or polishing with JB paste. It takes an agressive, controlled lapping action to make the bore uniform, and most conducive to shooting cast bullets.

Food for thought! :D

God Bless,

While the polishing compound applied to a cloth patch on an undersized bore-brush is great for polishing, it won't do a thing to alleviate the constricted conditions in a barrel caused from such things as dovetailed sights, dovetailed forend hangers, rollstamp engraving and threaded muzzle-brakes. Often times, if you'll take critical measurements when slugging a barrel, you'll find sometimes up to .003" constriction in a barrel in these areas. As such, when shooting cast bullets, is as though you're putting the bullet through an undersize sizing die, then the bullet is grossly undersize for the remainder of the bore's travel.

It doesn't matter whether a barrel is new or old, and well shot, those constrictions don't just go away from shooting jacketed bullets or polishing with JB paste. It takes an agressive, controlled lapping action to make the bore uniform, and most conducive to shooting cast bullets.

Food for thought! :D

God Bless,

I don't think you meant to equate abrasion with constricted areas-- two completely different situations. What you posted states the obvious.

You will see more barrels ruined as a whole than improved running those sand-like rough laps thru a bore. But it depends on what you call accuracy I guess. Firelapping a bore with the 'sands' again is just accellerated wear, which is primary in the throat. I read these methods of rolling the agent into the lube grooves-- but that discounts the inertia of accelleration of the slug, which will dump the 'sand' going down the bore. If anything-- running these course, gritting agents thru a bore just goes to prove how poorly made their were otta the factory if any improvement is noted.

Aladin,

I would wholeheartedly agree with you if indeed all one was doing was filling lube grooves with a randomly selected abrasive compound, then abritrarily firing them down a bore, and hoping for the best outcome! Indeed!

However, through developing the process of firelapping that we emply here at Beartooth, I did ruin quite a number of barrels in search of the right combinations of abrasive composition, carrying agent, abrasive diameter, bullet hardness, bullet velocity, preparation technique and loading sequences. You're absolutely, and inequivocally correct, that haphazard lapping approaches will ruin many barrels. Been there, done that. However, through those failures, came a great learning curve, and through those experiences came a systematic approach to the process, along with some refined and very specific materials and component parts combined with methodical application to acheive a very simple, nearly fool-proof technique that anyone with basic reloading background can follow, and acheive near dimensional perfection in internal barrel configuration and dimensions!

First off, most nationally promoted "fire-lapping" processes advocate using most any bullet, many even suggesting jacketed bullets for the process.... first recipe ingredient for disaster. Those lapping bullets need be exactly between BHN 11-12 for proper lapping performance.

Second disasterous suggestion of other lapping processes is to use loads of "normal working velocities" for firelapping. This is a sure-fire way of totally ruining the throat of any firearm! Velocity needs to be strictly held to 400-600 fps maximum for optimal results.

Thirdly, lapping compound simply dumped into lube grooves, as you have proposed in your post, is an absolute and total guarantee of firelapping failure. The lapping compound needs to be thoroughly imbedded into the BHN 11 bullets on all bearing surfaces, by using pressure to imbed the compound into the surface of the bullet... not merely sitting on the surface until being fired down the bore.

Further, you mention "sand-like rough laps". Indeed if one was foolish or ignorant enough to use an abrasive agent of such henious qualities, I would expect dismal failure as you have described. I assure you that all lapping agents aren't created equal! Many lapping project failures ocurred in arriving at the optimal lapping compound in the quest to perfect the fire-lapping equation. Not only are there assorted grit values, but add into that the differing composition of lapping agents and the variables can be almost dizzying. Through many trials, we have found that silicon-carbide is the absolute optimum compound for purposes of fire-lapping, bar none and we use only Laboratory grade comounds. There are many others used and advocated for this purpose, but I assure you that less than perfect results are the outcome to be sure.

Finally the carrying agent for that lapping agent is critical. To my notion, or knowledge there is no retail packaged commercial lapping compound available today that has the proper carrying agent to adeqately lubricate the soft BHN 11-12 lapping bullets while allowing a controlled lapping action during the process. Hence, we were forced to market our forumlation for the process, as the product we recommended for so many years is no longer availabe as a retail consumer item.

Now addressing your assertion "If anything-- running these course, gritting agents thru a bore just goes to prove how poorly made their were otta the factory if any improvement is noted." Over the last dozen years we have sold lapping components to literally thousands of customers, and here on these public forums I'll state that we had only two customers in all that time report a problem. One didn't follow directions with a 300 wby. and fired 100 lapping loads through his gun, and opened up the bore diameter, and had to use .311" diameter bullets in the gun, after which it shot .5 MOA groups.... not the fault of the lapping process, but operator error, and totally disregarding the process and proceedures set forth in the instructions. Second was a man with a Marlin 336 30-30, who ran 50 lapping loads through his gun at full-snort velocities, also disregarding the explicit instructions and proceedures laid out for the fire-lapping process, as a consequence, his throat was elongated by .156". Again not a fault of the process, but operator error, disregarding the established regimen for the operation.

Aside from these two incidents, I'm aware of no failures in the firelapping operation using our processes. In addition, there are many, many folks using this forum and others, that will attest to not only accuracy enhancement as a direct result of firelapping their guns, but also modest increases in velocity due to a decreased friction coefficient of the barrel, and a dramatic decrease or outright elimination of fouling in the bore, either from lead or jacketed bullets.

I would suggest that before blanketly dismissing and publicly bashing the process of fire-lapping you might consider the outcomes of real people, using a refined system, employing specialized techniques and products who are acheiving unsurpassed results. The success stories represented by the folks on these forums alone speak volumes!

With all due respect, I wish you a good day!

I got my bottle of lapping compound from LBT, quite a while back. Veral's comments in his book basically echoed Marshall's - he'd done the research, ruined plenty of barrels, and failure to follow his directions certainly wasn't going to do anybody any good!

Just like there is a distinction between correct, safe reloading procedures, and incorrect / unsafe procedures, there is likewise a distinction on doing lapping right and doing it wrong. Here we have an opportunity to bring to people's attention the correct means / methods.

From a wear standpoint, Aladin, I'll certainly conceded that it does add to wear on the gun, also per Veral, it would be comparable to firing several thousand jacketed bullets.

So I'd look at it the following way:

If I didn't lap I'd have perhaps a few thousand additional shots (by the way Veral was speaking of revolvers not rifles) yet these would be before I achieved peak accuracy.

However - I can get to that level of accuracy much sooner with far reduced cost by the lapping procedures. Personally I'd rather have my accuracy now.

As far as ultimate barrel life - two other observations:

1. The decrease in fouling (whether jacketed or cast) will save a bunch of time and effort cleaning the gun, and we do know that cleaning rod wear on the bore certainly can be detrimental to the life of the bore, despite our best efforts to prevent the cleaning rod from rubbing the bore.

2. Since I don't have to deal with fouling from cast bullets nearly to the extent I did, then I'll just shoot them from now on. The bore will last many times the life that it would have with jacketed bullets only.

Right now I've got a couple of centerfire rifles with rough bores that are going to undergo lapping and I'll be writing up the results for the forum.... stay tuned.

Wow! A firelapping converstaion! I first heard of firelapping about 15 years ago as described by Ross Seifried in G&A. So I got into it. Over the years I picked up Veral Smith's book covering the topic. Then I picked up Marshall's book on the topic. People I respect do not believe in it. People I respect believe in the benefits of firelapping. So I went to work to test it out myself.

Guess I have firelapped well over a dozen handguns & rifles in the last decade. The results varied but were never negative. My 30-06 M-70 went from a 1 1/2" shooter at 100 yards to a 1/2" shooter with the same load. A friends identical M-70 went from 2" groups to 1" groups. That was just after the initial firelapping with no other work done. I have a S&W 629 that shot heavy bullets well but sprayed 240gr swc all over the paper. After firelapping it shot those 240gr lead swc into under 6" groups at 100 yards (the edge of my skill level with iron sights and a 5" barrel).

In recent years I do not do an assessment first. Once I know the firearm is in good shape, I firelapp it. Invariably they are either very accurate or tack drivers. There is less leading and fouling of any nature. Like Marshall said, you have to do it by the rules for it to work right but the gains have always been worth the small effort. I have found the Beartooth lapping compound to be easily the best I have used. Marshall has it down right. I am hooked on all those benefits!

Bill

"I would suggest that before blanketly dismissing and publicly bashing the process of fire-lapping you might consider the outcomes of real people, using a refined system, employing specialized techniques and products who are acheiving unsurpassed results. The success stories represented by the folks on these forums alone speak volumes!"


I first will note that my posting a response to this quote has been blocked in the original thread... I can only speculate on why??

Removing constrictons in a bore is a complicated process-- to do it RIGHT. No method which-- IMO, employs charging a lead bullet with lapping agent however formulated works as easily as is stated here. Your results are going to vary-- due to where those tight areas are located and the knowledge you have of the barrel's internal dimensions. Finding these dimensions minus expensive equippment isn't easy. It requires firng a slug thru slowly and recovering it intact, cleaning and pushing it thru for 'feel'. NOT observing this critical step is flying blind-- the outcome is more chance than by design.

Newcomers to reloading-- those often shooten factory guns which have poor/wide manufacturing tolerances will find some relief polishing a bore by any means. These firearms are typically very rough-- any smoothing helps to some degree. Yet this improvement is underwritten by a shorter barrel life. Lapping with the 'sand' is just accellerated wear.

From my conversations over the yrs with those 'sand lapping', for every shooter claiming success there's at least one where the gun didn't improve-- or degraded it's accuracy. I found the last group tended to keep better records and more carefully compiled the target comparisions. Many people find it hard to go against the chorus-- hence they keep shut about negative results.

My message boils to this: if you have a good shooter-- 'sand lapping' isn't for you. Preserve you barrel and leave it alone. If you have a 3 MOA gun or worse-- it really doesn't matter. Likely any polishing or removal of constrictions will help to varying degrees. But be aware the results are going to vary greatly-- due to the system employed, how well you understand what's to be done, and how diligently you monitor the ongoing process. Few take the time to fully understand the why's-- and that's the major problem with sandlapping. No accuracy handloader who has access to a borescope would ever consider such a method-- be sure of that.

I have no axe to grind-- this is nothing personal against anyone marketing these kits. But every coin has two sides-- and I've sketched out the other side. That'll do it for me.

I'm sure I'm treading on something here, but I'll make a comment anyway. IMHO if you want a quality barrel, buy one. I built a 35 Whelen cupple years ago and put a quality barrel on it. It shot extremely well (with cast) from the getgo. I also own a jar of JBs. I've used it one time on a different rifle what had been rebarreled, and only then because I could feel a rough spot. It smoothed out. If I had a barrel that shot so poorly I felt compelled to fix it, I might consider a fire lap as a last resort before rebarreling. If it's broke, fixing it isn't gonna break any worse. sundog

Indisputatible point - anything done to smooth the bore in a firearm will result in metal removal.

Another indisputabile fact - the metal you want removed by lapping is that which is deleterious to projectile performance.

Yes, lapping of the bore will cause metal to be removed - however, that metal is what causes damaged bullets and are beasts to clean properly.

I've fire-lapped several bores using the NECO lapping kit and jacketed bullets (this is before I was aware of BTB's lapping kits with cast bullets being available). All firearms responded positively with the lapping, in that accuracy improved, pressure dropped and cleaning chores were made far easier. This was done on both moly chrome and stainless bores.

The act of cutting, hammering or pressing grooves in the bore will always result in machining chatter and scoring marks from the broaching tools. Some of these are minor and some are gross, as pointed out earlier, depending on the tolererances and conditions of the tools used. One of the best methods to remove these defects is hand lapping by a competent smith using proper lapping equipment and procedures. This is a cost additive the factories will not do, unless on a custom order basis.

You can, over time, accomplish the same burnishing by continued shooting of jacketed bullets to condition the bore, removing these imperfections. You can also, using a lapping kit, do the same thing in a much shorter period and with good results. Yes, both processes will remove barrel metal. That's how you smooth the wrinkles out. Lapping will hasten the end of a bore's useful life - so will continued shooting. For me, I'll lap a rough bore to get the accuracy and cleaning characteristics early and worry about a worn out barrel down the road after a some thousands of rounds have been pushed through it. Most barrel wear is from the gas cutting and erosion from the heat/pressure of powder combustion, anyway.

One other thing I will agree on - if you have a firearm that is shooting well to begin with, don't mess with it. Tinkering usually only makes things worse.

Removing constrictons in a bore is a complicated process-- to do it RIGHT. No method which-- IMO, employs charging a lead bullet with lapping agent however formulated works as easily as is stated here. Your results are going to vary-- due to where those tight areas are located and the knowledge you have of the barrel's internal dimensions. Finding these dimensions minus expensive equippment isn't easy. It requires firng a slug thru slowly and recovering it intact, cleaning and pushing it thru for 'feel'. NOT observing this critical step is flying blind-- the outcome is more chance than by design.

It's obvious either you are speaking on the experiences of others, or not really used common sense in determining what method to use in measuring the overall constriction in a bore, much less the obvious and revealing way of finding the location of those tight spots! GEEEEEZE, firing a bullet at low speed, recovering it, cleaning it, and then pushing it back through the barrel? GOOD GRIEF!!!!

It's no harder than taking a soft, pure lead oval egg sinker of appropriate diameter,(the kind used for fishing, available at any tackle store or sporting goods department, they are butter soft, so start and push through the bore easily, are egg shaped so are easy to get started in the bore and don't have a tremendous amount of bearing surface on the barrel, and lastly have a longitudinal hole running the length of the sinker allowing a place for the lead displaced by conforming to the bore to compress, without having a residual spring-back type memory) and starting it down the bore with a soft-faced mallet, then shoving it through a squeaky, slightly lubricated bore with either a cleaning rod or wooden dowel.

As the sinker encounters a tight spot, or constriction in the bore, it will become more difficult to shove the sinker through the bore, it's that simple! To measure the amount of overall constriction in the bore, simply start one sinker in the muzzle-end of the barrel, and extract it, then shove another through the enitire barrel, the difference in the measurements between the two will give the amount of constriction in that particular barrel. OK, I guess I missed somewhere the EXPENSIVE EQUIPMENT part of your assertion!


Newcomers to reloading-- those often shooten factory guns which have poor/wide manufacturing tolerances will find some relief polishing a bore by any means. These firearms are typically very rough-- any smoothing helps to some degree. Yet this improvement is underwritten by a shorter barrel life. Lapping with the 'sand' is just accellerated wear.

From my conversations over the yrs with those 'sand lapping', for every shooter claiming success there's at least one where the gun didn't improve-- or degraded it's accuracy. I found the last group tended to keep better records and more carefully compiled the target comparisions. Many people find it hard to go against the chorus-- hence they keep shut about negative results.

My message boils to this: if you have a good shooter-- 'sand lapping' isn't for you. Preserve you barrel and leave it alone. If you have a 3 MOA gun or worse-- it really doesn't matter. Likely any polishing or removal of constrictions will help to varying degrees. But be aware the results are going to vary greatly-- due to the system employed, how well you understand what's to be done, and how diligently you monitor the ongoing process. Few take the time to fully understand the why's-- and that's the major problem with sandlapping. No accuracy handloader who has access to a borescope would ever consider such a method-- be sure of that.

Apparently you missed, failed to note, or didn't read my previous post regarding "sand lapping"

Further, you mention "sand-like rough laps". Indeed if one was foolish or ignorant enough to use an abrasive agent of such henious qualities, I would expect dismal failure as you have described. I assure you that all lapping agents aren't created equal! Many lapping project failures ocurred in arriving at the optimal lapping compound in the quest to perfect the fire-lapping equation. Not only are there assorted grit values, but add into that the differing composition of lapping agents and the variables can be almost dizzying. Through many trials, we have found that silicon-carbide is the absolute optimum compound for purposes of fire-lapping, bar none and we use only Laboratory grade comounds. There are many others used and advocated for this purpose, but I assure you that less than perfect results are the outcome to be sure.

Finally the carrying agent for that lapping agent is critical. To my notion, or knowledge there is no retail packaged commercial lapping compound available today that has the proper carrying agent to adeqately lubricate the soft BHN 11-12 lapping bullets while allowing a controlled lapping action during the process. Hence, we were forced to market our forumlation for the process, as the product we recommended for so many years is no longer availabe as a retail consumer item.

No one here on these forums, or Beartooth Bullets, (the sponsor of these forums) advocates anything of the kind regarding putting "sand" down your barrel, for any purposes! What is recommended for those barrels with constrictions, or rough bores is the controlled use of a laboratory grade lapping compound, applied in a very specific proceedure. There's nothing haphazard or left to "chance" in that process. Lapping is nothing short of a form of controlled wear.... CONTROL is everything, and it must be done in moderation, and with precisely defined perameters and processes to positively control those effects. Sand won't do that..... laboratory grade lapping compounds will, and do!

I have no axe to grind-- this is nothing personal against anyone marketing these kits. But every coin has two sides-- and I've sketched out the other side. That'll do it for me.

Apparently you specialize in abstract sketches based entirely upon either someone else's miserable outcome which was perhaps caused through mis-information, a lack of proper education and familiarization of the process, or using a product ill-suited to the task at hand. Please, before sketching us any more bleak pictures, take an unemotional and logical look at the differences in perhaps what your perception of the process is, and look at the solid positive effects gained from a PROPERLY lapped barrel.

Good Day,

I've read the book, followed the procedure, and I'm a very satisfied customer!

As a machinist, I can say without reservation, every machining operation performed to produce a firearm is a form of controlled "wear". That same "wear", applied properly via firelapping has produced benifical to extraordinary results in many of my guns. I'm confident enough in the process to demonstrate that opinion (fact) to any skeptic with a rifle that needs help. An article in G@A by Ross Seyfried several years back inspired me to try the process; with attention to detail, equipment, and some effort you will not be disappointed.

Regards,
Bryan

As a machinist, I can say without reservation, every machining operation performed to produce a firearm is a form of controlled "wear". That same "wear", applied properly via firelapping has produced benifical to extraordinary results in many of my guns. I'm confident enough in the process to demonstrate that opinion (fact) to any sceptic with a rifle that needs help. An aricle in G@A by Ross Seyfried several years back inspired me to try the process; with attention to detail, equipment, and some effort you will not be disappointed.

Regards,
Bryan

THERE - that is the crux of the issue. No different than 'breaking in' your car engine, or sanding a piece of wood to make it smooth before you stain/finish it.

Do it correctly, take out what you need to, by following instructions and using the correct materials, and success should be expected.

Do it wrong, screw up, and you have yourself to blame.

Very well said Bryan.

" every machining operation performed to produce a firearm is a form of controlled "wear"


I find this an interatin' perspective. You must use very dull cutting tools...

Actually your notion is absurd. Machining is the process of profiling a metal part to fit a specific purpose. Good machining means close tolerances and a finished system that in the end functions with minimal wear.

Firelapping a gun barrel with the 'sand laps' is ONLY for the shooten irons of 3 MOA plus accuracy. Often this 'sand lapping' subsitutes for a good, thorough cleaning-- removing jacket material out of those recesses, something easily accomplished by other less invasive means.

As I previously stated-- my interest in posting the OTHER side pertaining to firelapping is only informational. I read alot of claims here that simply defy common sense. Anyone who's fired slugs thru a bore and recovered them intact understands the accelleration of the slug produces an inertia that spreads this 'lap' per the laws of psychics. Throat dia is always increased to some extent depending on the number of shots and grit number. Tight areas are relieved to varying degrees BUT the wear produced thorough the barrel is porportional to again the number of shots and grit number. At a minimum your making a 'new' caliber as the jacketed slugs made for this tube are going to produce more gas blowby, fouling and degrade their grouping potential.

The notion that said firelapping didnt' work in someone's gun and it's THEIR fault is typcial of the common 'one size fits all' mentality. Blame the poor fella who's ruined his gunbarrel-- for the firelapping products are user beware. Like you need to study for some degree to sucessfully accomplish the task.

There's MUCH simplier ways to remove bore constrictions & polish said bore-- MINUS the extra wear induced by running coarse lap agents thru your bore. Leave the sand on the beach...

Ha,Ha,
Sorry , gotta go to work now and "grind' (sand) my dull cutting tools!!
Later,
Bryan

Aladin,

Your postings are interesting, but being rude, insulting, and talking down on the members of the site is beginning to wear thin. If you can't be polite, take your discussions elsewhere.

Now - machining doesn't remove material? How is that possible????? Your response doens't make sense and is insulting to those who tried to bring a different perspective to the discussion.

Jacket material build-up - every credible source of lapping instructions very clearly states that all jacket material MUST be removed before the lapping process starts, else it is a waste of time, or worse. Those who don't read the directions still don't have my sympathy. The information is freely available....

I'm afraid you don't understand the concept of a 'lap.' The soft lead slug is intended to compress as it goes through any constriction or rough spot. The low pressures / velocities of lapping loads as advocated by Veral Smith, Marshall, and Ross Seyfried are not enough to make the lapping bullet 'slug up' again after it goes through a constriction. That is easily verified by checking the BNH of the recommended slug against typical lapping pressures.

Now, the reason jacketed bullets are NOT recommended for lapping, not here anyway, is that the jackets are much more elastic than lead, and WILL spring back a little after going through a barrel constriction. Even very hard lead bullets can do this to some degree.

I can guarantee you, that you CANNOT remove a bore constriction with a brush wrapped up with a patch and JB bore paste or ANY other product on the market, without wearing the bore excessively ahead of and behind the (former) constriction. The reason is that your brush acts just in the manner you describe as detrimental - it is putting pressure against the bore uniformly, whether it is running through the constriction or any other part of the bore!!!!!! This is due to the spring of the bristles.... exactly the kind of thing you want to avoid. You can't work the brush to the point of ensuring that it is ONLY wearing on a small part of the bore. For one thing the brush would be much longer than the typical bore constriction.

Yes lapping can and does change throat dimensions, minimally if done properly. That's all spelled out in the books too (you did read them before you started the discussion, correct?). Much like free-floating a barrel, you do it THEN work up your loads to match.

Last - I would urge you to seriously research how custom and benchrest barrel makers lap barrels. Here's a hint: soft lead slugs coated with abrasive. Coincidence? Don't think so. The skilled barrel maker can do this by hand. The lap performs as described, taking out the high spots, and compressing through them for minimal wear through the rest of the barrel. Just like a lapping load - when the directions are followed!

As far as excessive bore dimensions causing gas leakage and blow-by, it just isn't so. Bullets, by and large with the exception of weird stuff like steel-cored AP ammo, WILL obturate and fill the throat dimensions when subject to peak chamber pressures. At some point in the bullet's ride down the barrel, the gas pressure will drop down below the point of forcing a good seal. By lapping we have ensured that the barrel gets tighter toward the muzzle. So, a good gas seal is maintained - the bore keeps a bit of a 'squeeze' on the bullet.

I defy you to find a factory barrel that isn't just a bit oversized in relation to the jacketed bullets that are intended for it. It is extremely common for the manufacturers to run the bore dimensions 0.001" or so over the nominal bullet diameter, and for the bullet manufacturers to have their bullets on the 'small' side, perhaps by a few ten thousandths of an inch. Keeps pressures down, as the reverse could cause problems, and doesn't hurt a thing. For the benchrest guys, sure, they go to that level of detail. Nobody else needs to.

Now there might be a bit of gas leakage in the throat area till peak pressure is achieved. A lot of that depends on the powder being used, how much, burn rate, etc. If that was a catastrophic problem, there would not be a Weatherby on the planet (or any revolver ever made, for that matter) that would shoot worth a crap. Every rifle has a tiny bit of tolerance for the bullet in the throat - save perhaps the Schuetzen rifles where the bullets are seated by hand in the throat before inserting the cartridge. Revolvers have a huge jump to the rifling.

Like I said, if you want to be polite and discuss this and learn about it, great. If you want to be rude and insulting just to stir things up, go somewhere else. That sort of behavior is not only tolerated on other forums, but welcome. It is not here.

Well, darn it Marshall. I just ruined my .458 SOCOM barrel. I had a constriction under the brake and was shooting 1.5 MOA. I fire lapped the barrel and ruined it by shooting those sand impregnated bullets down the barrel. Now, with the constriction removed it only shoots 3/4 MOA. Darn the luck. :rolleyes:

As a follow-up to my lengthy post, I would hasten to add that 'abrasive machining' (ie grinding) is a well-known process, which as you might guess would involve removal of metal (or other raw materials) by use of abrasives.

This would be the closest parallel to firelapping, using a consumable (the bullet) to carry the abrasive material, rather than a fixed grinding wheel or the like.

MikeG, one thing I've been pondering is the lee side of a constriction. With a soft lapper squeezing down, it's work on the lee side is minimal or null until the constriction is gone. How do you know "when"? sundog

Clean the barrel and slug it after every 10 shots. Stainless Ruger revolvers usually need more lapping under the threads, so I'd slug less often. A Ruger owner may have a more precise number. Tight spots are very easy to feel with a little practise.

Bye
Jack

Good question -

You'll have to clean the barrel while at the range, then have something to slug it with (handful of muzzleloader roundballs and a can of WD-40 plus a brass rod).

Shoot 10 rounds, clean, see if you are making any progress, then continue as conditions indicate.

Good point and glad you brought it up. By the way, for rifles I just go ahead and load 20 rounds to start with. Revolvers I expect to take more due to the barrel constriction you get under the frame. I might load say 50 rounds for a revolver and check halfway.

Guess I'm more "old school" than ever. Last barrel lapped was done with the rod and cast laps. Does give some control over the tight spots, but takes a long time to get it done compared to fire-lapping. Personal choice, but it there is a detectable tight spot, will hand lap...if it's just a tad rough from end to end, will fire lap. If it doesn't give me any grief out of the box, will leave it alone.

Thinnk the answer is: if the pressure is still geater than the yield strngth of the alloy, then the lap will again obturate after the tight spot...if the pressure is less, it's going to stay sub-diameter.

I cleaned my bore and slugged it (two slugs to compare, one full length and one just into the muzzle) after every five shots. I slugged and cleaned it every shot between 20 and 25. I could have may be stopped at 23 or 24 shots.

Let it be known that I have nothing against hand lapping - there is an excellent article on this by C. E. "Ed" Harris in the 17th Edition, Handloader's Digest, page 193.

My suggestion of firelapping as opposed to hand lapping mostly comes from my belief that firelapping is a process requiring less skill / experience by the end user, and therefore a good way to get started.

I dunno guys! Do I smell a troll here or not!

I think its more like very strong opinions being expressed - some civily and some not.

All opinions are respected on this board. It is the manner in which they are presented that cause the most heartburn for us Moderators. Please keep the discussions civil and respectful - that way, we can all participate and even learn.

question guys does anyone make loaded .22 rimfire ammo with lapping compound impregnated in it like the beartooth lapping bullets. I have a ruger .22 with a constiction by the threads id like to lap out.

Lloyd,
With some sub-sonic .22 rounds, and some of Marshall's lapping compound, this is an easy quick fix. In a nut shell, you impregnate the .22 slugs with compound with your fingers and blast away. The Beartooth Tech. guide has detailed instructions and examples in it. Piece of cake !

Jeff

what type of ammo would you recomend i wouldnt think that shorts would be the way to go with that bullet having to jump so far by the way thanks for the advise.Lloyd,
With some sub-sonic .22 rounds, and some of Marshall's lapping compound, this is an easy quick fix. In a nut shell, you impregnate the .22 slugs with compound with your fingers and blast away. The Beartooth Tech. guide has detailed instructions and examples in it. Piece of cake !

Jeff

I actually have seen .22 lapping ammo for sale, might take a bit for the location to kick in.... hopefully someone else has seen it too.

Where else - Brownell's.

About halfway down for the .22 rimfire stuff.

http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=12715&title=FINALFINISH?%20SYSTEM

I got a message from somebody wanting to know how jacketed bullets would perform in the lapped barrel. I had just a few minutes yesterday evening before dark to stop and shoot some rounds.

I cycled 5 rounds with the Hornady 265-grain FP at about 90 second intervals. This is in front of 47.0-grains of Reloder 7. It's high because the rifle is sighted in for the 310-grain Lee but this group is no more/no less of what I expected prior to the lapping. I did not use a lot of care in shooting the rounds and I forgot the sight-in targets. Found this one laying on the ground and it was very hard to see at dusk and 100 yards.

http://cuero.nodial.net/~lindareamy/Jacketed_in_lapped_barrel_350x440.jpg

Lower 3 are from my plinking rounds, I could only find 3 because my dad and son-in-law have shot them all up at pesky critters. I've never shot that 200-grain bullet that far.

thanks mike