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Barrel break in.

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Barrel break in. was created by SOC

Some people go to extremes with their barrel break in procedure. Here is what I've done for my AR-10TU.

First 10 - 1 shot and clean with JB past and mop, run dry patch to remove excess, than lightly oiled patch using FP-10

Next 10 to 100 - 10 shots and clean with FP-10 on Boresnake. Test with FP-10 patch before and after to verify level (hopefully decreasing over time) of copper fouling.

So far I have 20 rounds down the pipe.

Personally I wanted to start doing 5 and 10 shot accuracy and reliability tests ASAP.

Armalite triple laps so that should help. I also used lots ant lots of passes with JB bore compound to speed the process.

The 300 RSAUM is also an "Overbore" cartridge and throat erosion will happen faster vs 308.

As I understand it the throat is what your trying to polish.

When your chamber was cut the tool left marks in the throat aria across the bore axis. When the rifle is fired copper is shaved off the bullet by these marks and vaporized by the powder gasses.
As the powder gasses cool the copper adheres to the bore.

So even though it looks like the copper in the bore is from the rifling it's really from the throat.

Please share your own thoughts and procedures on barrel breakin and conditioning.
10 years 9 months ago #24956

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Replied by Lizardette on topic Barrel break in.

Never broken in a barrel in my life. Someday, I'll build two identical rifles and break one in. You know, for science. If I'm bored.
10 years 9 months ago #24957

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Replied by faawrenchbndr on topic Barrel break in.

I do not really "break in a barrel"
I do however, shoot about 20 rounds then clean normally. I do not let the barrel get hot for the 1st few hundred rounds. I do not use a BoreSnake, those are like using a dirty mop to clean a floor.
I use solvents, nylon brushes, jags and patches. No pastes, no metallic brushes in my barrels.
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10 years 9 months ago #24980

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Replied by SOC on topic Barrel break in.


Have you tried a bore snake?

They work, as verified by running a clean oiled patch afterword to check.

If they look or smell dirty a little dawn and hot water cleans them right up.
10 years 9 months ago #24993

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Replied by faawrenchbndr on topic Barrel break in.

Yes.......I have tried them, I own about 10 or 12 of them.
Unless you use them once and then wash them, you are just mopping a floor with a dirty mop. I'll stick with a patch that I can use once and trade for a new clean one.

**Edited to add......

I do use BoreSnakes, but I ONLY us them in a clean bore. I use them to remove residual oils left in the barrel before shooting.
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Last edit: 10 years 9 months ago by faawrenchbndr.
10 years 9 months ago #24994

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Replied by SOC on topic Barrel break in.

A sparkling clean bore (free of all oil and fouling) will exacerbate "Cold bore" shot variation.

FYI in the field snipers go as long as possible without cleaning the bores of their rifles.
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10 years 9 months ago #24996

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Replied by Lizardette on topic Barrel break in.

SOC: Damned skippy.

I like my barrels the way I like my women. Hot, and dirty.
10 years 9 months ago #25003

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Replied by faawrenchbndr on topic Barrel break in.


Wow,.......ya think you are teaching me something new?
You keep mopping your floor with a filthy mop........I'll stick with what has worked for me for the last 30+ years.
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10 years 9 months ago #25004

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Replied by SOC on topic Barrel break in.


Just posting some of what I've learned myself and from others in 9 years at a job where putting rounds down range means life or death.
10 years 9 months ago #25013

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Replied by faawrenchbndr on topic Barrel break in.

So, you are just regurgitating what you were told? It is best to learn by doing, seeing & experiencing.

I know a thing or two about conditioning barrels, cold bore shots, and maintaining a barrel in the field.
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10 years 9 months ago #25019

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