Stainless Steel Barrel
- Thread starter jgrin
- Start date
TheBlueEyedBear
'The Nut Behind The Trigger'
From the Krieger website (one of the top barrel makers):
BREAK-IN & CLEANING:
With any premium barrel that has been finish lapped -- such as your Krieger Barrel --, the lay or direction of the finish is in the direction of the bullet travel, so fouling is minimal compared to a barrel with internal tooling marks. This is true of any properly finish-lapped barrel regardless of how it is rifled. If it is not finish-lapped, there will be reamer marks left in the bore that are directly across the direction of the bullet travel. This occurs even in a button-rifled barrel as the button cannot completely iron out these reamer marks.
Because the lay of the finish is in the direction of the bullet travel, very little is done to the bore during break-in, but the throat is another story. When your barrel is chambered, by necessity there are reamer marks left in the throat that are across the lands, i.e. across the direction of the bullet travel. In a new barrel they are very distinct; much like the teeth on a very fine file. When the bullet is forced into the throat, copper dust is removed from the jacket material and released into the gas which at this temperature and pressure is actually a plasma. The copper dust is vaporized in this plasma and is carried down the barrel. As the gas expands and cools, the copper comes out of suspension and is deposited in the bore. This makes it appear as if the source of the fouling is the bore when it is actually for the most part the new throat. If this copper is allowed to stay in the bore, and subsequent bullets and deposits are fired over it, copper which adheres well to itself, will build up quickly and may be difficult to remove later. So when we break in a barrel, our goal is to get the throat “polished†without allowing copper to build up in the bore. This is the reasoning for the "fire-one-shot-and-clean" procedure.
Every barrel will vary slightly in how many rounds they take to break in For example a chrome moly barrel may take longer to break in than stainless steel because it is more abrasion resistant even though it is a similar hardness. Also chrome moly has a little more of an affinity for copper than stainless steel so it will usually show a little more "color" if you are using a chemical cleaner. (Chrome moly and stainless steel are different materials with some things in common and others different.) Rim Fire barrels can take an extremely long time to break in, sometimes requiring several hundred rounds or more. But cleaning can be lengthened to every 25-50 rounds. The break-in procedure and the cleaning procedure are really the same except for the frequency. Remember the goal is to get or keep the barrel clean while breaking in the throat with bullets being fired over it.
Finally, the best way to tell if the barrel is broken in is to observe the patches; i.e. when the fouling is reduced. This is better than some set number of cycles of "shoot and clean" as many owners report practically no fouling after the first few shots, and more break-in would be pointless. Conversely, if more is required, a set number would not address that either. Besides, cleaning is not a completely benign procedure so it should be done carefully and no more than necessary.
BREAK-IN & CLEANING:
With any premium barrel that has been finish lapped -- such as your Krieger Barrel --, the lay or direction of the finish is in the direction of the bullet travel, so fouling is minimal compared to a barrel with internal tooling marks. This is true of any properly finish-lapped barrel regardless of how it is rifled. If it is not finish-lapped, there will be reamer marks left in the bore that are directly across the direction of the bullet travel. This occurs even in a button-rifled barrel as the button cannot completely iron out these reamer marks.
Because the lay of the finish is in the direction of the bullet travel, very little is done to the bore during break-in, but the throat is another story. When your barrel is chambered, by necessity there are reamer marks left in the throat that are across the lands, i.e. across the direction of the bullet travel. In a new barrel they are very distinct; much like the teeth on a very fine file. When the bullet is forced into the throat, copper dust is removed from the jacket material and released into the gas which at this temperature and pressure is actually a plasma. The copper dust is vaporized in this plasma and is carried down the barrel. As the gas expands and cools, the copper comes out of suspension and is deposited in the bore. This makes it appear as if the source of the fouling is the bore when it is actually for the most part the new throat. If this copper is allowed to stay in the bore, and subsequent bullets and deposits are fired over it, copper which adheres well to itself, will build up quickly and may be difficult to remove later. So when we break in a barrel, our goal is to get the throat “polished†without allowing copper to build up in the bore. This is the reasoning for the "fire-one-shot-and-clean" procedure.
Every barrel will vary slightly in how many rounds they take to break in For example a chrome moly barrel may take longer to break in than stainless steel because it is more abrasion resistant even though it is a similar hardness. Also chrome moly has a little more of an affinity for copper than stainless steel so it will usually show a little more "color" if you are using a chemical cleaner. (Chrome moly and stainless steel are different materials with some things in common and others different.) Rim Fire barrels can take an extremely long time to break in, sometimes requiring several hundred rounds or more. But cleaning can be lengthened to every 25-50 rounds. The break-in procedure and the cleaning procedure are really the same except for the frequency. Remember the goal is to get or keep the barrel clean while breaking in the throat with bullets being fired over it.
Finally, the best way to tell if the barrel is broken in is to observe the patches; i.e. when the fouling is reduced. This is better than some set number of cycles of "shoot and clean" as many owners report practically no fouling after the first few shots, and more break-in would be pointless. Conversely, if more is required, a set number would not address that either. Besides, cleaning is not a completely benign procedure so it should be done carefully and no more than necessary.
jonbearman
I live in new york state,how unfortunate !
I try to always buy stainless due to anti rust qualitys and break in in my opinion is pretty much the same as any other barrel. You must follow the barrel makers break in anyways. Shoot one ,clean and so on usually till 10 rounds have been fired. Then it goes to shoot 2 clean for 10 rounds and continue until it stops coppering up real quickly,then I go 3 shot groups and clean ,looking for copper.If I shoot a 3 shot group after the break-in and it basically doesnt foul hardly at all and you are done. Also dont shoot groups without allowing the barrel to cool between groups. Cleaning of the barrel is almost impossible to predict.I find high quality barrels clean up quickly and then you need to insure you get the carbon out of the throat and l the grooves in the bore. I use iosso bore paste for that. Also this should been under the general discussion forum title. You will get tons of responses.
I don't think this topic belongs in the Classifieds
TheBlueEyedBear
'The Nut Behind The Trigger'
You're right BADDOG. But, since it's here:
I was chatting with a friend on this site a little while ago and decided to post one of my responses to Jon. And, this is just my opinion:
My break-in process is pretty much controlled by my habit since I learned a long time ago the shoot once, clean, shoot once, clean ETC...
I don't think there is such a thing as being anal when you spend the amount of money for a good stainless barrel especially if you have it fluted. If you have it fluted and then screw up the barrel, you just can't take off the flutes and move them to your new barrel. You have to start all over with that $400.00 outlay for another barrel and the time it takes for the barrel and the fluting. 12 WEEKS?! It's just not worth it to me.
The thing is, if someone is having problems with a barrel not shooting and they are asked about the break-in process; I believe you may hear something other than the truth. Break-in process DOES make a difference. Just my humble opinion.
Barry
I was chatting with a friend on this site a little while ago and decided to post one of my responses to Jon. And, this is just my opinion:
My break-in process is pretty much controlled by my habit since I learned a long time ago the shoot once, clean, shoot once, clean ETC...
I don't think there is such a thing as being anal when you spend the amount of money for a good stainless barrel especially if you have it fluted. If you have it fluted and then screw up the barrel, you just can't take off the flutes and move them to your new barrel. You have to start all over with that $400.00 outlay for another barrel and the time it takes for the barrel and the fluting. 12 WEEKS?! It's just not worth it to me.
The thing is, if someone is having problems with a barrel not shooting and they are asked about the break-in process; I believe you may hear something other than the truth. Break-in process DOES make a difference. Just my humble opinion.
Barry
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