So...Breaking in New Barrel Is a Scam?

[MontanaRifleman]

Moman,

phorwath could probably do a better write up than me because he has more experience with it, especially with new barrels.

I used it on on 2 used Senderos, a 25-06 ans a 300 RUM. The 25-06 was badly fired cracked from throat to muzzle according to a smith who bore scoped it for me after it took my 5 days to get it clean. It's a great shooter though. The 300 RUM was a few years old and had 20 rounds down the tube plus about 6 more from me to check velocity before the treatment. My results were positive but not real conclusive. The celan easier, (the 25-06 cleans much easier) but they are still fowlers. The 25-06 showed some apparant velocity improvement but based on accuracy of my equipement, I'm not sure I would say that's a definite, but it shoots some very incredible velocities with RL17, but then again I've seen RL17 boost velociteis about 200 fps in another rilfe. Not sure about velocity increase in the 300 RUM. Light conditions were not great for the "after" test.

To sum it up, the rifles clean easier and there may be some velocity improvement and what I'm really hoping for is extended barrel life. The norm for the 300 will be about 1000 give or take which might take me a couple of years to reach. It will be very interesting to see how long the fire cracked 25-06 holds out. The smith was surprised that I could hit anything with it. It shoots sub .5 MOA. They both last about 70-80 round before needing a claening.

I plan to use it on a Sako that has about 200 rounds through it, which I broke in when new. It has started fouling a little again, so I'll see If I can stop that and get some better velocity with it.

Will post the long version probably by end of week and maybe Paul can give us his experience as well.

 

[Topshot]

I have read through this thread and have not seen the reason why I believe that running in a new barrel is a good idea. So here goes.

When a gunsmith cuts the chamber, the reamer is turning at right angles to the barrel rifling. This means that small steel burs will form on the edge and corners of the lands.

Now a barrel might end up with more of a larger bur on one particular land than another, some lands may not have any burs.

So when you first fire the barrel, copper builds up on these burs. The larger the bur the more the build up. You want to remove all this copper so that the powder gas can wear away the burs and leave a nice sharp and even set of lands.

If you leave some copper to build up on one land but not the others then you will obviously get uneven wear on the lands. This is detrimental to long term accuracy.

Avoiding uneven wear of the lands is the main reason to run in a rifle barrel.

After the initial run in period and all the burs have been erroded away from the lands by the powder gases, then you should be right to clean and shoot as normal.

 

[Coyboy]

I have read through this thread and have not seen the reason why I believe that running in a new barrel is a good idea. So here goes.

When a gunsmith cuts the chamber, the reamer is turning at right angles to the barrel rifling. This means that small steel burs will form on the edge and corners of the lands.

Now a barrel might end up with more of a larger bur on one particular land than another, some lands may not have any burs.

So when you first fire the barrel, copper builds up on these burs. The larger the bur the more the build up. You want to remove all this copper so that the powder gas can wear away the burs and leave a nice sharp and even set of lands.

If you leave some copper to build up on one land but not the others then you will obviously get uneven wear on the lands. This is detrimental to long term accuracy.

Avoiding uneven wear of the lands is the main reason to run in a rifle barrel.

After the initial run in period and all the burs have been erroded away from the lands by the powder gases, then you should be right to clean and shoot as normal.

Topshot, if the smith uses a sharp reamer and the correct sized pilot the burs are absent to nonexistent. The reamer does leave slight marks in the throat it cut but the same applies to tha,t if sharp and finished with care the throats are very smooth as well. What I see when a barrel is bore scoped during inital fireing is the copper build up tends to be on the last 1/3 of the barrel closest to the muzzle.
The first 1/3rd shows little to no copper but more carbon.

 

[MontanaRifleman]

Topshot, here's the way I see it. I'm no expert and have only broken in one new barrel and two used barrels. For whatever the reason, when a bullet is sent down the tube, carbon, copper and more carbon are laid down in the bore. I assume the reason copper is laid down is mostly due to irregularities in the surface of the steel, be it lands, grooves or edges. The theory goes, if you fire a bullet down a clean bore against bare steel, it will smooth out and remove these irregularities.

My experience in breaking in my Sako was that after the 13th shot was that the fouling basically all of a sudden stopped. The two previous shots showed a little less fouling, but after the 13th it had almost compleletly stopped. I fired again and cleaned again - same result, clean patch when previously I had been seeing blue patches. I fired a three shot group and cleaned again and almost the same result, a very liitle copper fouling was all I could detect. So for me, seeing was believing. Since then, I have seen the fouling come back, but it stills cleans fairly easy. I had sent it in to the factory a couple of times where they cleaned it with amonia products and I think steel brushes (unbelievably they recommend the use of steel brushes on bores) so I'm not sure what damage they may have done to the bore and maybe some moisture got in and pitted it slightly.. who knows? One day I'll get a bore scope.

Bottom line for me is I have seen the before and after difference. So it seems worth while to do it if it reduces fouling and possibly extends time beween needed cleanings.

 

[Boss Hoss]

Topshot, here's the way I see it. I'm no expert and have only broken in one new barrel and two used barrels. For whatever the reason, when a bullet is sent down the tube, carbon, copper and more carbon are laid down in the bore. I assume the reason copper is laid down is mostly due to irregularities in the surface of the steel, be it lands, grooves or edges. The theory goes, if you fire a bullet down a clean bore against bare steel, it will smooth out and remove these irregularities.

My experience in breaking in my Sako was that after the 13th shot was hat the fouling basically all of a sudden stopped. The two previous shots showed a little less fouling, but after the 13th it had almost compleletly stopped. I fired again and cleaned again - same result, clean patch when previously I had been seeing blue patches. i fired a thre shot group and cleaned again and almost the same result, a very liitle copper fouling was all I could detect. So for me, seing was believing. Since then, I have seen the fouling come back, but it stills cleans fairly easy. I had sent it in to the factory a couple of times where they cleaned it with amonia products and I think steel brushes (unbelievably they recommend the use of steel brushes on bores) so I'm not sure what damage they may have done to the bore and maybe some moisture got in and pitted it slightly.. who knows? One day I'll get a bore scope.

Bottom line for me is I have seen the before and after difference. So it seems worth while to do it if it reduces fouling and possibly extends time beween needed cleanings.

There you go folks----hit the nail on the head.... Good post....