CHROME LINED BARREL BREAK IN PROCEDURE

[MegademiC]

AFAIK chrome lining actually fills in the imperfections in the bore leaving only the high spots to worry about. But if it takes a few thousand rounds to knock down the high spots in the chrome, I mean I knew chrome was tough but thats a lot of rounds. Maybe shooting steel jacketed bullets would smooth it out faster.

Chrome plating has poor throwing power, and does not fill low areas well, and overplates in high spots. Not saying what you said is wrong, just adding details.

[BlueCorn]

Another waste of bandwidth. Barrel break in, really, you've got to be kidding me. This is how you do it. Clean and lube your new AR. Take it to the range and shoot it. Clean and relube after you're done shooting. Barrel break in, especially with a chrome lined barrel is BS

[tehpwnag3]

I'm not a sponsored shooter, just a guy who has shot quite a bit of benchrest and high power. I used to do the one-&-clean procedure to "micro hone" the bore thinking that my time and patience would pay off. After many years, I came to the realization that the barrel is about as good as it will ever be, right out of the box, and it's a slow death from there. These were high-end SS barrels.

As for CL, just shoot it.

[bruin]

My cynical side says that barrel mfgrs perpetuate break-in for one simple reason...to sell more barrels. All that cleaning (and worse, abrasives) just wears out barrels faster.

Everyone agrees that you need to clean brand new barrels to get rid of any preservative or manufacturing residue (i.e. from nitriding). As I understand it, barrels do "wear in" but not from any break in procedures - simply from firing. This burnishes the throat (which hand lapping doesn't polish) and happens in nitrided and CL barrels as well as stainless. It doesn't take a whole lot of rounds to do this either, maybe 20-40.

Cleaning during this throat wear-in period serves to reduce copper buildup in the bore. The premise is that copper buildup reduces the accuracy potential of the barrel. If you believe this, then clean your barrel often at this stage with decreasing frequency. Otherwise, shoot away and be happy.

[tom12.7]

Maybe, we can look into this a different way, depending on objectives for end goals. For most non precision uses, there is really no need to do much more than basic maintenance. The possible change to that may occur with end goals that require more precision. Burnishing in the bore to its own potential can benefit from reducing erosion in areas that would net a negative for that role. Certain combinations can cater towards burnishing with minimal erosion, versus some combinations that tend to erode higher in areas. I would tend towards preferring burnishing ammunition combinations that erode less than one that erodes more overall. Any cleaning would be depending on the characteristics of that, for carbon and copper mostly independently.
With high quality SS barrels, the first 100-1,000 rounds most likely have the highest precision potential. With high quality chrome lined barrels, that potential comes in later and can last longer for their own perspective roles. A SS barrel can have the potential to be much more precise than a chrome lined one, but a chrome lined barrel burnished in and maintain a level of precision for an end goal much longer. Adding excess erosion before the rest of the base barrel comes in is a net negative to the lifespan of that compared other alternatives.

[vicious_cb]

Chrome plating has poor throwing power, and does not fill low areas well, and overplates in high spots. Not saying what you said is wrong, just adding details.

Didnt know that, thanks for the additional detail.

Maybe, we can look into this a different way, depending on objectives for end goals. For most non precision uses, there is really no need to do much more than basic maintenance. The possible change to that may occur with end goals that require more precision. Burnishing in the bore to its own potential can benefit from reducing erosion in areas that would net a negative for that role. Certain combinations can cater towards burnishing with minimal erosion, versus some combinations that tend to erode higher in areas. I would tend towards preferring burnishing ammunition combinations that erode less than one that erodes more overall. Any cleaning would be depending on the characteristics of that, for carbon and copper mostly independently.
With high quality SS barrels, the first 100-1,000 rounds most likely have the highest precision potential. With high quality chrome lined barrels, that potential comes in later and can last longer for their own perspective roles. A SS barrel can have the potential to be much more precise than a chrome lined one, but a chrome lined barrel burnished in and maintain a level of precision for an end goal much longer. Adding excess erosion before the rest of the base barrel comes in is a net negative to the lifespan of that compared other alternatives.

So how does one burnish a CL'd precisionish barrel? Take us through your ammo selection and cleaning process.

[pinzgauer]

Forget the mfg, but at least one well known mfg admitted in a forum that they posted break-in procedures just to reduce the number of calls on the subject when they did not have them.

Basically said it won't make a difference, but won't hurt if reasonable

Shooters just don't believe they don't need break-in.

[tom12.7]

Didnt know that, thanks for the additional detail.



So how does one burnish a CL'd precisionish barrel? Take us through your ammo selection and cleaning process.

I wouldn't hold my breathe waiting for me to post any specific load details ever again in an open forum. Been there and it costs for basic information to be miss used and applied in such a way that it could ever take that path again.
For a possible precisionish role with a chrome lined barrel, I make possible exceptions to my normal maintenance and shoot as normal routine.
Different powders have different characteristics. I would rather see a powder choice that reduces erosion at some key locations compared to others. I wouldn't want to burn the throat or port anymore with what I can obtain versus a selection that tends to erode those areas more. Sure, some is a give and take, depending on application. If my objective may include precision, then erosion tends to be a negative.
GM jacket fouling tends to accumulate in the bore less than some others. GM is normally much easier to remove from the bore compared to some other possible offerings.
The actual loads selected with the above in mind does not reduce any of the possible negatives to zero, just less than other possible approaches.
If the goal is possible precision in a new chrome lined bore to burnish the surface to a point where the possible precision potential may be obtained, then we have ways to take advantage of that and minimize the losses.
As far as a cleaning schedule, I do not think that any excessive cleaning is required or stripping the bore for most. Just dealing with the carbon, and/or copper as normal to maintain, and possibly improve precision towards a potential.
If you look at it otherwise and use the negatives, you could end up in a place where the base barrel suffers when negatives hurts what that base barrel could have potentially been.

[ubet]

My favorite: https://www.youtube.com/watch?v=TRRahHX9Zkg

I remember when he posted that! It sent a lot of people up in arms. If I remember right, he was up in Alaska and a bit of a jack ass though.

Best part, he's shooting towards a road! Lol

[AKDoug]

I remember when he posted that! It sent a lot of people up in arms. If I remember right, he was up in Alaska and a bit of a jack ass though.

Best part, he's shooting towards a road! Lol

He's a logger. They do shit like that and they don't care. BTW.. looks like he's shooting in S.E. Alaska. Pretty tough to do any long range shooting in areas like that without shooting towards a logging road. Most of them are closed and the population is thin. Plenty safe to do.