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Fire-Lapping new barrel?

Michael BaquetMichael Baquet Member Posts: 63 ✭✭
edited March 2002 in Ask the Experts
I just ordered an STG 58A from DSArms. They suggest a logn process of breaking in the new barrel...shooting 1 round, cleaning barrel. etc, etc. What is your opinion on Fire-Lapping with such bullets as the ones put out be NECO. Also, is this necessary or does it simplt inprove accuracy by creating smoothe rifleing groves?
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  • Tailgunner1954Tailgunner1954 Member Posts: 7,734 ✭✭
    edited November -1
    I wish I could fide the webpage that had MacMillians take on breaking in a barrel and the use of abrasive compoundsBasicly he said to go out and shoot it, clean after every 20-25 shots (less if accuracy dropped off sooner).He also stated that you void the warrenty if you put any abrasive (bore paste, lapping compound, etc) in the barrel.IMHO Firelapping is even more abrasive than the compounds. Don't use it in a new barrel, save it for one that won't shoot and than only as a last resort.
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  • Tailgunner1954Tailgunner1954 Member Posts: 7,734 ✭✭
    edited November -1
    OK found it on another board http://www.serveroptions.com/ubb/Forum5/HTML/002592.html here is the exerpt I was speaking of:Found this post by Gale McMillan and thought I would share any comments?DonGale McMillanThe break in fad was started by a fellow I helped get started in the barrel business . He started putting a set of break in instructions in ever barrel he shipped. One came into the shop to be installed and I read it and the next time I saw him I asked him What was with this break in crap?. His answer was Mac, My share of the market is about 700 barrels a year. I cater to the target crowd and they shoot a barrel about 3000 rounds before they change it. If each one uses up 100 rounds of each barrel breaking it in you can figure out how many more barrels I will get to make each year. If you will stop and think that the barrel doesn't know whether you are cleaning it every shot or every 5 shots and if you are removing all foreign material that has been deposited in it since the last time you cleaned it what more can you do? When I ship a barrel I send a recommendation with it that you clean it ever chance you get with a brass brush pushed through it at least 12 times with a good solvent and followed by two and only 2 soft patches. This means if you are a bench rest shooter you clean ever 7 or 8 rounds . If you are a high power shooter you clean it when you come off the line after 20 rounds. If you follow the fad of cleaning every shot for X amount and every 2 shots for X amount and so on the only thing you are accomplishing is shortening the life of the barrel by the amount of rounds you shot during this process. I always say Monkey see Monkey do, now I will wait on the flames but before you write them, Please include what you think is happening inside your barrel during break in that is worth the expense and time you are spending during break inI answered this and lost it on transfer so will shorten this one and try to get my point across in fewer words. When some one uses JB on one of my rifles I void the warrantee! For two reasons. ! it dimensionally alters the barrel dimensions and not evenly and the second reason is the barrel maker laps the barrel with a grit of lapping compound that is most effective in preventing metal fouling. Then a customer polishes that finish away with JB.I wouldn't be as apposed to it if it were applied on a lead lap and very sparingly. It is very obvious when you look at a barrel with a bore scopes all the sharp edges are worn off the rifling. if it has JB used on it on a regular basis. As you know ,it is an abrasive of about 1000 grit. As for using it on factory barrels I will say that while it is difficult to hurt a production barrel but the thing that hurts a match barrel will do the same to a factory barrelI would rather see you use Otters Foul out as it is easy on the barrel. I have only used it on my 50 but it worked well on it.That is right. it is a waste of barrel and time. I don't know much about lined barrels but it may be that the barrel is rough due to the plating process. With high volume fire as in full auto it helps to protect against erosion and no one is concerned with accuracy as it is spray and pray.Look at it this way, A barrel starts out with nice sharp areas of the corners of the rifling . Along the way you build a big fire in it a few thousand times and it burns the corners off. Now take a barrel that to break in you put an abrasive on a patch and run it in and out. The result is that you take the corners off the rifling so that all that fire which would have started with sharp rifling is now starting with rifling that is thousands of rounds old. Which means that a lot of the life is gone. A lap always cuts more on each end where the compound reverses direction as it starts back through the barrel which means that it is enlarging the bore at each ends of the barrel. And last picture a patch riding along the barrel with abrasive on it. It is removing material at a given rate. It comes to a place where there is copper fouling and it rides over it cutting the same amount that it was cutting before it came to the copper. You continue until all the fouling is gone and what have you done? You have put the came contour in the barrel steel that was in it when it was metal fouled. It would not be as bad if it were used on a lead lap but I ask why would you want to abuse the barrel when you can accomplish the same thing without the bad side effects. There is Sweats, Otters foul out or just a good daily cleaning with a good bore cleaner till the fouling is gone. To top this off I will relate a true happening. I built a bench rest rifle for a customer and as usual I fired 5 groups of 5 shots and calculated the aggregate. It was good enough to see that the rifle was capable of winning the Nationals so I shipped it. I got a call from the new owner saying how happy he was with it the way it shot. About 4 weeks later the rifle showed up with a note saying it wouldn't shoot. Sure enough when I tested it was shooting groups three times the size if the ones I had shot before I shipped it. When I bore scoped it the barrel looked like a mirror and the rifling wasn't square it was half round. From that time on I put a flyer in each gun saying if any abrasive was use in it voided the Warrantee.Now I am not trying to stop you from doing what you want but just inform you what is happening when you use JB. Brass brushes are softer than barrel steel and does no harm. S/S brushes are harder than barrel steel is definetly a no no. Nylon may surprise you to know is very abrasive If you doubt this look at the carbide eye on your fishing rod where nylon line has worn groves into it.The metal shavings would have had to get in the barrel after it was test fired. The barrel was a hammer forged or buttoned barrel which is not machined and is very smooth finished. No one ever said not to clean a new rifle only that it is not necessary to break it in.
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  • Michael BaquetMichael Baquet Member Posts: 63 ✭✭
    edited November -1
    WOW !I had no idea. Thanks in advance for saving my bore. It's not a bench rifle but I still like to go to the range and shoot the smallest group possible.Thanks, Mike
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  • Tailgunner1954Tailgunner1954 Member Posts: 7,734 ✭✭
    edited November -1
    No problem
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