New barrel break in

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  • Last Post 25 November 2023
Wayne S posted this 28 March 2010

I just  installed a new Savage  {OME} heavy weight barrel  in 308 on my switch barrel Savage rifle. This will be a deciated cast bullet only barrel and potentional “postal match” set up.

Are there any tricks to a new cast bullet only barrel break in ??

 

Wayne

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RicinYakima posted this 28 March 2010

FWIW, when I bought my Savage FP10, I shot 60 rounds of NM 7.62 NATO to fire form the brass. I shot 10, couple of patches of Hoppe's #9, let it soak a couple of minutes, dried and shot 10 more. Cleaned and de-coppered the barrel down to bare metal, patched with Fliz for about 10 passes. Since then have been shooting cast for 8 years with just a wet Ed's Red patch and two dry ones. Seems to be as smooth as they make them. Ric

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Wayne S posted this 28 March 2010

Thanks, I'll reshearch Ed's Red Patch's

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Wayne S posted this 28 March 2010

Just wondering everyones thoughts on filling a couple of the lube groves with JB Paste or valve polishing compound and fireing them at sbout 1200 fps followed by several “fritz ” lubed bullets ?? followed by the usual cleaning ??

But I think I do have 50 or more old pulled military bullets I could use ??

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DAMRON G posted this 28 March 2010

I have done the JB in lube groove trick on old military rifles and it worked well to get the crud out.I brake in barrels by shooting them and seeing how they do first. If they shoot good don't worry about the “ritual” barrel break in in my opinion.

George

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RicinYakima posted this 28 March 2010

The concern I have with firing a bullet with abrasive is that you have no control of lateral pressures. It could make a oval or unknown shape to the throat. While I have done it, it was a last resort. For the length of the bore, I have used Ken Mollohan's (Molly in the CBA and on the net) guidance of using a cloth wrapped brass bore brush and using it by hand. Ric

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Wayne S posted this 28 March 2010

:dude:K.I.S.S.  Me like that

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DAMRON G posted this 28 March 2010

RicinYakima wrote: The concern I have with firing a bullet with abrasive is that you have no control of lateral pressures. It could make a oval or unknown shape to the throat.  

I have done this in about 10 rifles and havent seen any problems,but i only shoot the bullets with enough powder to just get them out of the barrel.When i was using a NECO firelap kit i did wash one throat out with cast bullets trying to clan up a rough spot in a barrel.I then found out from a friend that he switched to jacketed bullets for lapping to resolve the issue caused by obturating cast bullets..At least its a good use for jacketed bullets<G>

George

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CB posted this 29 March 2010

Wayne, the talk about jacketed bullets I also agree with.

I know a past cb shooter who did tests with many combinations of fire lapping. He used a bore scope to inspect each test. The best results was with 2 or maybe 3 shots with the heaviest jacketed bullet at a low velocity. He also found that 400 grit creates about the best results. Very fine polishing of the bore isn't necessary as that will cause higher friction and heat. The purpose is to only knock down any burs or loosen a slight tight spot.

The only other grit I use is 'JB Bore Bright' bore cleaner. It is a garnet based compound which is the safest grit for bores. I've used 6-7grs of Unique with a 200gr jacketed bullet in my 30 calibers...............Dan

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JetMech posted this 30 March 2010

I broke a 2 groove Springfield barrel last week. I had loaded 9 rounds of a 180gr bullet over a starting load of IMR4350. Decoppering after every round and using ed's red w/lanolin after, by the forth round, the barrel was noticeable smoother. In fact, it felt as smooth as my hand-lapped Badger barrel. I shot a fifth round but decided the others weren't needed. Done.

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Wayne S posted this 30 March 2010

Dan Willems wrote: Wayne, the talk about jacketed bullets I also agree with.

I know a past cb shooter who did tests with many combinations of fire lapping. He used a bore scope to inspect each test. The best results was with 2 or maybe 3 shots with the heaviest jacketed bullet at a low velocity. He also found that 400 grit creates about the best results. Very fine polishing of the bore isn't necessary as that will cause higher friction and heat. The purpose is to only knock down any burs or loosen a slight tight spot.

The only other grit I use is 'JB Bore Bright' bore cleaner. It is a garnet based compound which is the safest grit for bores. I've used 6-7grs of Unique with a 200gr jacketed bullet in my 30 calibers...............Dan Dan,

Thnks, did your friend use the J-bullets by them selfs or were they coated with the 400, OR did he just “scrub” the bore wirh the 400 grit and a tight fitting brush or mop. or put it in a greese groove or two on a bullet like a 311466

As to the JB Bore Bright, I think I read somewhere here to coat the bore with JB and then fire a low veloicy  over size .310 for a 308 bore {?}> bullet.??

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CB posted this 30 March 2010

Wayne S wrote: Dan,

Thnks, did your friend use the J-bullets by them selfs or were they coated with the 400, OR did he just “scrub” the bore wirh the 400 grit and a tight fitting brush or mop. or put it in a greese groove or two on a bullet like a 311466

As to the JB Bore Bright, I think I read somewhere here to coat the bore with JB and then fire a low veloicy  over size .310 for a 308 bore {?}> bullet.??

All lapping bullets should be rolled into the compound you are going to use. I know shooters who say they are getting good results by filling grease grooves on CBs or by leaving compounds in the bore and shooting, but I don't think that is the correct way. Leaving loose compounds on the bullet or in the bore can cause a hydraulic effect and cause the lateral forces (as Ric states) or waves as the bullet travels down the bore causing inconstant polishing.

The grit needs to be embedded into the surface of the bullet to be carried the length of the bore. JB is harder to embed than 400 grit compound. When I use BoreBright I still roll the jacketed bullet between 2 plates of glass, but may leave the surface as-is and not wipe it dry. If you coat the bore with JB, use a dry patch (no liquid cleaner) leaving behind the least amount in the bore.

Like Dollar Bill states, it is simple enough to do like you say KISS. You will not get much of any results lapping by hand with a patch or mop. Hand lapping is done with a bore slug and is difficult to do and to achieve the right results. A barrel can be ruined by over fire-lapping so care is needed to watch the condition like Dollar Bill did..................Dan

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amb1935 posted this 30 March 2010

I fired about 20 rounds of mothers mag polish vocered CBs with reduced loads out of an old m91/30. I wasn't happy with the bore condition but wasn't reallyscared to mess anything up. Keep in mind, that is not nearly as aggressive as 400 grit compound. It polished the bore up quite nicely.

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canalupo posted this 30 March 2010

Most barrel break-in information is a myth. The only time anyone should shoot a bore polishing compound in a barrel is if there is a noticable rough spot. The rough spots are usually due to slop in barrel or rust. A derusting agent (not naval jelly that has acid in it) swabbed in barrel and super cleaned is the most a damaged/rusted barrel requires. All barrels will polish and break-in nicely just from shooting and keeping them clean during the first 100/200 rounds or so. save time and aggravation and enjoy shooting that will do the job.

Check the shilen barrel website or any reputable barrel maker and you will probably get the same advice.

My two cents and I'm sticking with it.

Good luck

Bob D

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argie1891 posted this 30 March 2010

was at the range when a shooter was breaking in a new rifle. What fun shoot one shot clean for 5 min. shoot a shot clean shoot clean shoot clean. i dont mind the shoot part but spending 3 hours shooting a box of shells just isnt my bag. the kicker on this he was breaking in a marlin lever action in 44 mag. how much better could he make it? I think that the manufactures use their break in as an excuse if the rifle dosent shoot they can always blame the purchaser for not following the directions exactly. joe gifford

if you think you have it figured out then you just dont understand

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JetMech posted this 30 March 2010

I've seen hundreds, if not thousands of machined parts over the years. It's a pretty rare case where one comes out of the machine, even cnc machines or water jets, where they do not require some degree of deburring or other cleaning up, besides degreasing. I did look up a couple barrel manufacturers and most recommend some barrel break-in. The exceptions are those that hand-lap barrels. Yes, I spent 4 hours breaking in a barrel, but it was one shot, put the rifle down, shoot 10 CBs fron another rifle, run a couple patches thru, shoot one, 10 CBs from another rifle, etc... I've just spent, total actual time, about 1 hour to ensure a factory barrel will deliver the best accuracy possible, for as long as I have it, which will be in the neighborhood of 30 years and will see thousands of carefully cast and handloaded rounds thru it. I hour work......30 years of confidence....it's a no-brainer to me.

Lapping compounds: I won't do it. Ed Harris recommended I run a tight patch with Bon Ami in an old bore to clean it up. Worked like a charm. No throat or muzzle damage. Different suject, though. Wayne was asking about new barrel break in.

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CB posted this 30 March 2010

Dollar Bill wrote: I've seen hundreds, if not thousands of machined parts over the years. It's a pretty rare case where one comes out of the machine, even cnc machines or water jets, where they do not require some degree of deburring or other cleaning up, besides degreasing.  Wayne was asking about new barrel break in.

That's right, Wayne was asking about an (OME) Savage barrel. There is quite a difference between what Shilen makes and what Savage makes. There most likely isn't any need to lap a custom barrel, but production firearm barrels are a different thing.

Caffee, the most re-known 22 rimfire riflemaker says the worst thing about shooting the lead bullet 22s in the machine marks left in the barrel from cutting the chamber and throat. It won't go away by just shooting.

I've never heard a bad thing from the any of the Production Class shooters who have done a jacketed 2 or 3 bullet lap and only praise the quality of their barrel afterwards............Dan

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muley posted this 30 March 2010

on the subject of barrel breaking in, Roy Dunlap in his gunsmithing book suggests firing about 100 rounds of lead bullets, for the same effect as using a lead lap by hand, also much easier and enjoyable

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mlr1m posted this 09 December 2010

Hand lapping is great. Its also time consuming and hard work. If done correctly it will be perfect from end to end. Fire lapping is just the new microwave quick fix. I do not see how it can have the same effect the whole length of the barrel as it does at the throat.

Michael

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CB posted this 09 December 2010

It seems logical that fire lapping would have more effect nearer the chamber and less towards the muzzle. I have heard it claimed that that was true.

I had a barrel that had a loose area in the middle. The bore was tight on a lead slug for the first 8 inches or so and then there was little or no resistance until about an inch before the muzzle when it tightened up again. Slugging near the muzzle and an inch ahead of the throat gave about the same dimensions. I had no way to measure the diameter in the middle without sawing the barrel in two.

I reasoned that if most of the effect of fire lapping was near the chamber I should be able to enlarge the back of the bore so it didn't size down cast bullets early and then let gas by in the middle causing fouling.

I fire lapped and slugged both the bore ahead of the throat and the “choke” at the muzzle. When it became obvious that the fire lapping was enlarging the bore at the muzzle at least as much as at the rear I stopped. What are the experiences of other fire lappers?

John

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Scearcy posted this 24 February 2017

I was going to start a new thread and the forum software brought up this old thread. I have an unfired factory barrel that I am going to put on my Remington 700.  The barrel is a 243. In general I am a member of the camp that prefers to clean my barrel after every 20 rounds during a match. Remove any burrs, facilitate cleaning, etc. In the past I have lightly (5 rounds or so) fire lapped a couple of barrels. One was a Springfield and the other was a Savage CM.  I wasn't aware of the risks and I was satisfied with the outcome.

The new barrel is SS and I have grown a bit more cautious about damaging a barrel. Thoughts?

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onondaga posted this 24 February 2017

Scearcy   My simple bore polishing method works great with stainless  barrels and completely breaks in a barrel without firing a single shot: http://castbulletassoc.org/thread/8364-my-bore-polish-method-to-shoot-better/   Gary

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Bud Hyett posted this 24 February 2017

 Having an unreasonable desire to have a RIA Springfield (I once worked there), I bought one mail-order that was advertised as possible slight pitting. The pit was one from breech to muzzle. Calling around, I found a 1903 barrel with sights at a local shop in original wrapping.

Having it installed, the gunsmith noted the machining marks on the top of the lands. Shooting it with cast and jacketed produced three-inch to six-inch ten-shot groups with the usual .30 caliber molds. One Saturday evening, with nylon bore brush, cleaning rod, patches and J-B Bore Paste; I proceeded to run three hundred strokes; five strokes, remove patch, new patch, add J-B Bore Paste and do it again.

The only good thing was a local television channel was rerunning Star Trek episodes in a marathon. . 

After three hundred strokes, the bore was much shinier, but a bore-scope would still see traces of the machining marks on top of the lands. The rifle went under an inch for ten shots with Reloder #7 and the Lyman 311335 bullet at 1650 feet-per-second. This is a lot of work, however, the results are worth it. 

Farm boy from Illinois, living in the magical Pacific Northwest

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RicinYakima posted this 24 February 2017

Either Gary's or Bud's methods work equally as well, having done both. With the barrel out, Gary's may be easier, but barrel installed I think Bud's would be. Just getting the “big chunks” flatten out will help, but polished bright does not seem to do anything extra.

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onondaga posted this 24 February 2017

 BHyett ypu said,
"I proceeded to run three hundred strokes; five strokes, remove patch, new patch, add J-B Bore Paste and do it again."
You would need 2,000+ strokes with your method to compare with my polishing method.
One pull with a Hoppe's BoreSnake loaded with Chrome polish per my method is more effective than 20 passes with  JB loaded patches. My polishing method is 100 pulls with the snake loaded every 10 pulls with Turtle Wax Chrome polish and rust remover that is 500 grit that cuts chrome and brings it to a high shine. I regularly get happy reports. The only negatives are from people that make substitutes and change the method or do it incompletely.
Gary

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Ken Campbell Iowa posted this 25 February 2017

gary's method with the snake is technically correct as a polishing method .

i did a test with clover grits of 280, 400, 800, 1200 .. and the old ( aggressive ) .jb ...  on polished steel plate samples ...

the 400 was the slowest i would use to do any polishing down of any significant tool marks in barrel steel ... the finer grades are unnecessarily slow ...  the striations left by 400 ( or turtle wax 500 ) ... don't seem to detract from even 22 rf accuracy in match barrels .  i believe shilen laps with 280 grit .  i suppose any striations can be regarded as just small rifling .

i have seen comments that there is such as thing as too smooth a barrel ... i would need to see the documented tests for that ; i tend to think too smooth is unlikely ... but this needs more testing .    my 1-example input to that is that in my match 22 rf barrel which shot about 0.6 moa i shot about 3 or 4 thousand rounds with jb in the lube through it .. it shot 0.6 before and after the test , and i could see no throat advancement with nose engraving or borescope .    very shiny, however .

for a new factory barrel i would shoot 4 with 280 grit pressed into a mj bullet  .. this for the throating burrs .  then gary's snake treatment or equivalent for the rest of the barrel.  i do use his turtle wax chrome polish to slick up gun actions , even took a little of the russian out of my own makarov rails ... impressive .

while on fire-lapping i had a buddy who kept fire-lapping his big-name match barrel until it shot ... after 40 firelap y tests  failed he set it back  and re-chambered .. ha... it never shot ... smooth wasn't the problem with that barrel ... 

ken

 

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RicinYakima posted this 25 February 2017

" i tend to think too smooth is unlikely ... but this needs more testing"

Precision shooting published a test on this (1990's?), and that was the answer; once it reached point X it never got any better, just reflected more light..   

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Scearcy posted this 25 February 2017

Here are before and after pictures.  Since the barrel was not mounted on an action yet, I used Gary's method.  I did the full 100 passes with the bore snake. There are two before and two after. You'll have no difficulty telling which is which.

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Scearcy posted this 25 February 2017

Now the after:

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Scearcy posted this 25 February 2017

I LIKE IT!

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onondaga posted this 26 February 2017

Scearcy

I've seen this many times, your pictures are excellent and display what I have told you about my polishing method. You refined your bore finish significantly. It will require no break in at all now and will be easy to maintain. You could have tested velocity if the barrel was mounted. The polishing also gives a slight increase in velocity for the same load after polishing.   If you have the opportunity, please post your pictures and make comment in my original post with your success story. That old post of mine still gets a lot of hits and your pictures and comments would be very supportive there:

http://castbulletassoc.org/thread/8364-my-bore-polish-method-to-shoot-better/

 

Just clean up your BoreSnake as discussed and it will be great for the range regimen cleaned and dry to aid in consistency. Pull the clean dry snake through 2x before a shooting session then once every 5 shots during the session. This regimen yields match consistency by aiding in lowering the ES statistic of velocity significantly.

I wish you the best in your application.

 

Gary

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M1fuzz posted this 13 November 2023

I want to see Gary’s method but, the updates to the CBA has rendered the page closed. Any assistance would be appreciated.

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Bud Hyett posted this 13 November 2023

One pull with a Hoppe's BoreSnake loaded with Chrome polish per my method is more effective than 20 passes with  JB loaded patches.

My polishing method is 100 pulls with the snake loaded every 10 pulls with Turtle Wax Chrome polish and rust remover that is 500 grit that cuts chrome and brings it to a high shine.
I regularly get happy reports.
The only negatives are from people that make substitutes and change the method or do it incompletely.
Gary
Above is a reply from Gary detailing his method. I've not tried it. I might this winter since I want to clean up the bores on several prairie dog rifles. 

Farm boy from Illinois, living in the magical Pacific Northwest

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OU812 posted this 13 November 2023

I have used 000steel wool and lapping compound to open throat for precise bullet fit using bumped boreride bullets. I would not be afraid to use 000steel wool and some type of fine compound to remove sharp edges inside factory barrel before final breakin.. Such as shooting jacketed bullets and cleaning frequently between shots.

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mashburn posted this 16 November 2023

I have always broken rifle bores in this way. I USE NO ABRASIVE PASTE. I shoot one round and clean, and I do this for 5 rounds, cleaning after each shot. I then shoot five rounds and clean and continue this five shot and clean until I have fired a total of 50 rounds. I class rifle barrels into three groups ,foulers, semi-foulers and non-foulers.

 

I know nothing of the top ideas are for cast bullet barrel break in, but I do know they must be slick. These are jacketed bullet barrels that I have always broken in this way, Let's face it, some barrels are junk and not matter what process you follow, they aren't going to be good barrels, no-matter what you do. You know the old saying, that you can't make a silk purse out of a sow's ear.

Mashburn

David a. Cogburn

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RicinYakima posted this 16 November 2023

I only have 30/06 match rifles. I shoot 10 USGI AP rounds, clean and start shooting cast. 

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John Alexander posted this 16 November 2023

The trouble with barrel break in is because, according to most, it has to be done at the initial firing there is no way to test whether it does anything. You either do it or you don't at the start no trying the other way.

As one data point, Tony Boyer the GOAT of benchrest shooting doesn't do it.

John

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mashburn posted this 17 November 2023

Hello John,

I agree with, you that the bore break-in has to be done with the initial firing, and like you said, you will never know what you accomplished. The only thing that I can say for sure is, I broke in all of my prairie dog gun barrels this way and I guarantee you that it is a great start to have a rifle that will fire many rounds before it fouls. And like I said, I started with good barrels. A rifle barrel that is smooth enough to stop a lot of fouling, should also be an accurate barrel. thanks John.

Mashburn

David a. Cogburn

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mashburn posted this 17 November 2023

Thumbs up for Mr. Ed. Harris, when he said, that he would not use any lapping compounds in a new barrel, that is exactly my thoughts. Sometimes with old junk barrels, I would be enticed to do something of that sort, but not with a new barrel. here is something to think about; Take a buffing wheel and try to buff the receiver of rifle that has some square corners and has a tangent to a curve. Most of the time unless you are very experienced with a buffing wheel, you will round these corners off. When I run something down a bore, even to clean, I want that tight fitting patch, backed up by something perfectly round and firm. That is why I feel that firing with jacketed ammo and frequent cleaning is the best bet. That way you're not going to round off the edges of the landMashburn

David a. Cogburn

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MarkinEllensburg posted this 17 November 2023

When you mill something on a lathe or mill do you just leave the surface with the tool marks? If you do your work is not pleasing to the eye. If you milled a receiver would you leave all surfaces as milled or polish or lap the mating surfaces together? 

Should you lap? Will it hurt? Answers are nebulous. John is correct in that there is no way to experiment to prove either way. We are left with antecedents. It has worked for me. Would my rifles have been better if I had not used JB Bore paste? Doubtful,

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Tom Acheson posted this 18 November 2023

For my prarie dog rifles and my CBA match guns I never fooled with the "break-in drill". As a subscriber to Precision Shooting magazine, I remember writer Merril Martin doing a lot of work with wads under the cast bullet. He also gave people barrel lapoing kits that included small containers of abrasive, ranging from coarse to fine. You lubed the cast bullet and then rolled the bullet over a layer of the abrasive to get the abrasive to "stick" to the lube, then fired the round. X number of shots with #1 abrasive, then X number of shots with #2 abrasive, etc.

Never did see follow-up reports on the results people had.

Tom

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Bud Hyett posted this 18 November 2023

As a subscriber to Precision Shooting magazine, I remember writer Merrill Martin doing a lot of work with wads under the cast bullet. He also gave people barrel lapping kits that included small containers of abrasive, ranging from coarse to fine. 

Never did see follow-up reports on the results people had.

Tom

Ed Doonan obtained a kit and did four barrels. He published a report in a letter to friends, I do not believe this report was published in The Fouling Shot. The barrels were; 1) new custom barrel, 2) a new factory barrel, 3) a used custom barrel shot  approximately 3,000 rounds, 4) a well-worn barrel. He tested before and after lapping using ten-shot groups as his criteria. I'll summarize what I remember.

The results were: 

  • The new custom barrel showed no improvement. 

  • The new factory barrel showed some improvement.

  • The used custom barrel show some improvement.

  • The well-worn barrel showed no improvement.

His thoughts:

  • The custom barrel was already factory lapped, thus needed no improvement .

  • The new factory barrel probably still had some machining marks left needing some help. 

  • The used custom barrel needed some smoothing, possibly in the leade area.

  • The worn barrel was a worn barrel and nothing could help it. 

This is a short summary from memory, Ed included the size of the groups. If I can find the letter, I'll submit it for publication in The Fouling Shot

Farm boy from Illinois, living in the magical Pacific Northwest

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Brodie posted this 25 November 2023

I bought a Zastava mini in 7.62x39, and the barrel as it came was a horrid scratchy mess with tool marks and obviously no attempt had ever been made after cutting the rifling to smooth the bore what-so-ever.  I shot about 200 paper patched bullets, nothing on the patch but the calcium from our "soft" water here, and the barrel smoothed out nicely.  It no longer grabs patches that go through and the bore is much smoother to the feel of my hand when I clean it. 

B.E.Brickey

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