Barrel Break-in

[1967spud]

Taken from www.6mmbr.com

 

How to Break-in a Barrel -- A Dissenting Point of View

Gale McMillan, of McMillan Stocks fame, was one of the finest barrel-makers and benchrest shooters of all time. Here he argues that elaborate barrel break-in procedures do more harm than good.

Comments collected from Gale's Gun Forum postings.

 

As a barrel maker I have looked in thousands of new and used barrels with a bore scope and I will tell you that if every one followed the prescribed [one shot, one clean] break-in method, a very large number would do more harm than good. The reason you hear of the gain in accuracy is because if you chamber a barrel with a reamer that has a dull throater instead of cutting clean sharp rifling it smears a burr up on the down wind side of the rifling. It takes from one to two hundred rounds to burn this burr out and the rifle to settle down and shoot its best. Any one who chambers rifle barrels has tolerances on how dull to let the reamer get and factories let them go longer than any competent smith would.

 

Another tidbit to consider--take a 300 Win Mag that has a life expectancy of 1000 rounds. Use 10% of it up with your break-in procedure. For every 10 barrels the barrel-maker makes he has to make one more just to take care of the break-in. No wonder barrel-makers like to see this. Now when you flame me on this please [explain] what you think is happening to the inside of your barrel during the break in that is helping you.

 

Consider this: every round shot in breaking-in a barrel is one round off the life of said rifle barrel. No one has ever told me the physical reason of what happens during break-in firing. In other words what, to the number of pounds of powder shot at any given pressure, is the life of the barrel. No one has ever explained what is being accomplished by shooting and cleaning in any prescribed method. Start your barrel off with 5 rounds and clean it thoroughly and do it again. Nev Maden, a friend down under that my brother taught to make barrels was the one who came up with the [one shot one clean] break-in method. He may think he has come upon something, or he has come up with another way to sell barrels. I feel that the first shot out of a barrel is its best and every one after that deteriorates [the bore] until the barrel is gone. If some one can explain what physically takes place during break-in to modify the barrel then I may change my mind. As the physical properties of a barrel don't change because of the break-in procedures it means it's all hog wash. I am open to any suggestions that can be documented otherwise if it is just someone's opinion--forget it.

 

It all got started when a barrel maker that I know started putting break-in instructions in the box with each barrel he shipped a few years ago. I asked him how he figured it would help and his reply was if they shoot 100 rounds breaking in this barrel that's total life is 3000 rounds and I make 1000 barrels a year just figure how many more barrels I will get to make. He had a point; it definately will shorten the barrel life. I have been a barrel maker a fair amount of time and my barrels have set and reset benchrest world records so many times I quit keeping track (at one time they held 7 at one time) along with High Power, Silhouette, Smallbore national and world records and my instructions were to clean as often as possible preferably every 10 rounds. I inspect every barrel taken off and every new barrel before it is shipped with a bore scope and I will tell you all that I see far more barrels ruined by cleaning rods than I see worn out from normal wear and tear. I am even reading about people recommending breaking-in pistols. As if it will help their shooting ability or the guns'.

 

 

 

 

 

What are members thoughts on this please?

[6mmBR]

So will you be breaking in the Spud gun then?

Dave

[1967spud]

no no no no no no YES

[mildot]

When i first got into centre fires i tried the shoot one clean etc but got bored after the 2nd time so decided it was shoot 1 clean shoot 5 clean shoot 5 clean then clean after each load while load testing. but have 2 shots to fould the barrel before the test loads. Seems to have worked for me.

 

I know a couple of people who i dont think have cleaned their rifles properly since they got them! cnat say they are tack drivers but for foxing they are accurate enough!

[eldon]

His comments on the shooting in for 100 - 200 rounds rings true for my Remmington. It has settled down nicely now and reliably prints groups after a slightly disappointing start. I went from an ADL to a VS and didn't get instant gains but I have in the long run.

 

Maybe its just if the copper is stripped and not removed adequately whereas the shoot once clean once routine overcomes any shortfalls in your cleaning, solvents and practices.

 

I suppose it depends how you quantify adequate accuracy, you can get anal and lets not forget its diminishing returns.

[Redfox]

Gale Mc Millan was a heck of a shooter and made good barrels most of the time, but he wasn't an engineer or a firearms designer. He was entitled to his opinion but that doesnt make it gospel or scientific in any way and if he had a barrel that didnt shoot, he just made up another one until he got a good one.

Target barrels ( he was a target shooter) have an understandably short life normally and then get retired. The world of firearms design and materials has moved on considerably since then, but it appealed to an American public who mostly rarely clean or maintain their rifle from one year to the next. Exceptions to this are our own Andrew, Marine PM1 and Panther 308, who's opinions I would value anytime and of course the many very professional target/benchrest shooters across the pond.

redfox

[1967spud]

Gale Mc Millan was a heck of a shooter and made good barrels most of the time, but he wasn't an engineer or a firearms designer. He was entitled to his opinion but that doesnt make it gospel or scientific in any way and if he had a barrel that didnt shoot, he just made up another one until he got a good one.

Target barrels ( he was a target shooter) have an understandably short life normally and then get retired. The world of firearms design and materials has moved on considerably since then, but it appealed to an American public who mostly rarely clean or maintain their rifle from one year to the next. Exceptions to this are our own Andrew, Marine PM1 and Panther 308, who's opinions I would value anytime and of course the many very professional target/benchrest shooters across the pond.

redfox

 

 

good imput there rf

[onehole]

All barrels are different some need break in and a few dont? most of the barrels Iv,e come across lets start with factory,they can take a long break in and show heavy fouling over at least a huindred rounds or more,custom/quality barrels from as little as 15 rounds through to about 40 rounds max.Then you get SAKO factory barrels at least the{older} ones I,ve had which practically need no running in and for example my recent TRG no copper from round one and you can feel the quality when cleaning smooth as glass.Rarely gets copper solvent down its tube these days just some kroil to wash out powder fouling.

I know its a pain to do this process but strangely pleasurable just to watch the deep blue pale away to nothing after perhaps 20 or 30 rounds down a tube.I think a high strength solvent should be used during this process .Go on just do it.onehole

[Chris-NZ]

..

The core of a bore brush is steel also.And one can see that if its not inserted properly

it too can damage the rifling.

 

..

308Panther

 

 

Not all Pat- pretty sure the core of the ones I get from Sinclair are bronze/copper alloy/.. of some sort

 

cheers

Chris-NZ

[Andrew]

The problem is that those who shoot-in their barrels have accurate rifles. Would it be as accurate if they hadn't?? Well. One will never know.

 

Like McMillan, other makers have said that running in a barrel is senseless. I have not done it and own some accurate rifles so my own experiences substantiate that. What Marine PMI and I found testing prototype 17 caliber barrels is that shooting, we believe, removes the last vestiges of manufacturing lubricants. We have found various 17 caliber barrels from the same maker to require anywhere between 20 and 200 rounds to reach peak accuracy. We found no pattern to it.

 

In defense of McMillan, he made barrels before the age of CNC when barrels were essentially hand made. He filled a void with accurate barrels before every Tom, Dick, and Harry got into he business. If he made a bad barrel he scrapped it and started again. Most barrel makers toss barrels regularly. He was not a metallurgist but he is a barrel maker with decades of experience. Personally,I can live with that. JMHO ~Andrew

[ejg223]

Did the following to my last three rifles, out of the box I ran several patches with peek

through the barrel. (Peek is a very fine polish) Only when changing patches exiting the muzzle

and several strokes between. I stop when the barrel has no more rough spots and shines.

On my last remmy barrel it only took 10-15 min. The last three rifles seemed very consistent

from there on. I clean the bore if we get soaked hunting, or after say every two months.

Just don't trust dampness and powder left overs. Do a peek treatment maybe once a year.

I've been lapping metals and high end ceramics for over 20 years, one gets a feeling for how

much one removes, sometimes we are talking nanometers not micrometers.

 

edi

[Ronin]

Did the following to my last three rifles, out of the box I ran several patches with peek

through the barrel. (Peek is a very fine polish) Only when changing patches exiting the muzzle

and several strokes between. I stop when the barrel has no more rough spots and shines.

On my last remmy barrel it only took 10-15 min. The last three rifles seemed very consistent

from there on. I clean the bore if we get soaked hunting, or after say every two months.

Just don't trust dampness and powder left overs. Do a peek treatment maybe once a year.

I've been lapping metals and high end ceramics for over 20 years, one gets a feeling for how

much one removes, sometimes we are talking nanometers not micrometers.

 

edi

 

 

I think Edi that you would be final polishing or hand lapping the factory barrel (something I am sure isnt done with the care of a custom made barrel at the factory)

 

This probably has more effect to factory tubes than a bespoke barrel, although I have nothing scientific to substantiate that.

 

 

My own experience.

 

I used to shoot one, clean, for ten, shoot three and clean for four or five groups and then shoot five shot groups cleaning bettween them all.

 

 

Now?

 

I just shoot the rifle and clean it when the barrel tells me it needs cleaning....

 

 

My 6.5x47 (with a Lothar tube) had three rounds through it as break in, cleaning after each one, I got so little copper out of it, I gave up and shot it.

 

It shots .3" back then (2-3 yrs ago)

 

I used it in a competition on sunday and during one detail shot a .2" group (it averages .3" still) even with 3000 rounds through the tube.

 

The 7mm WSM (F Class gun), has a Broughton, I shot two break in shots cleaning after each one and then started load development, cleaning after each session (25 - 30 rounds)

 

I noticed it showed very little copper, but also noted that velocity started to rise with an "accuracy" load over the period of 100 shots (of the same load)

 

Now that has settled down to single digit ES.

 

 

I dont think there is any way of telling how many rounds it takes to "break in" a barrel, my formula is "just shoot the damn thing" and enjoy it!

[1967spud]

The 7mm WSM (F Class gun), has a Broughton, I shot two break in shots cleaning after each one and then started load development, cleaning after each session (25 - 30 rounds)

 

Ronin for your break in shots, did you use your starting load data for breakin in ?

 

if you can see what i am trying to ask

[Elwood]

I went through the break in procedure with my 22BR which had a Border cut rifled 5R barrel. I was nearly in tears when the best group it could manage was about 1 - 3/4 inch at 100 yards (full blown custom rifle) I was at Minsterly at the time and the rifle was getting quite a bit of attention from the other guys and gals I went up there to meet, so you can imagine my horror and embarrassment.

 

As the day went on I started to notice through my teary eyes that the groups had started to shrink, after 100 shots it was now shooting 1/2 inch groups and getting smaller.

 

It's now had 400-500 shots and a bit more load development, it now shoots as it should do, .2's

 

My 6BR just shot stupidly small groups from day one ( Krieger)

 

I always clean a new barrel, the most copper ever I ever took out of my TRG was cleaning it prior to shooting it from new!

[onehole]

Elwood-TRG you found the same as me then?!!!!!

I think basicaly when and if your rifle doesn,t show any copper then it has been run in or never needed it in the first place.END.Onehole.

[Ronin]

Spud

 

unless I am shooting a rifle with a chamber reamer ive already used (so have load data for that chamber in effect) I would use max load minus 5-10% as a starter and work in increments of .3 or .5 grain upwards (depending on case volume).