Bore Fouling?

Hard Head

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Joined
Jun 30, 2015
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187
Location
WI
I was wondering how many fouling shots does your rifle take before it is really ready to rumble? My Bergara HMR Wilderness seems to take about 7-8 shots then is ready for some real accuracy. The other question is do you have to clean your rifle after 7-8 fouling shots so you can be ready in a couple weeks to shoot a tight group or do you have to clean and start all over again? Pete
 
I have several that don't require fouling shots but my 300 WSM needs 2-3 to start shooting right. I didn't discover this until 2 or 300 shots were down the tube. And the discovery was made after superimposing first group from clean bore with the next group-both five shot groups. I found the first 3 shots from a clean bore printed over and inch and then the next 7 went into 1/2 "
 
I have about 90 rounds down my barrel now, last 3 shot groups, 1st was 1.120 second 3 was ,782 and 3rd was .375, not sure if it gets better with more shooting and fowling shots start to shrink , Pete
 
I don't own ANY rifles that require fouling to be accurate…
I also don't own ANY rifles that produce cold bore shot differences, all those that have come across my path that did this were moved on.
What I want is cold bore accuracy AND fouled bore accuracy that doesn't change for 40 shots or more, not just 3-5 shots in a string.

Cheers.
 
I've found it depends on the machining of the barrel. Factory barrels tend to need fouling shots to smooth the boor with copper fouling. Where custom barrels tend to shoot more true clean or fouled. The one thing I've also found is barrel temperature. Being a bench rest shooter, my barrel requires about five shots to bring the barrel to an accurate temp for consistency.
 
You can say and believe what you want about barrel break in,but I shoot and clean my new barrels for the first twelve shots.Those rifles will shoot in the same group cold bore,clean or fouled.I don't go through an extensive cleaning after each shot.I run a wet patch followed by a dry patch and shoot.This is the last new rifle barrel before and after 12 shots.I used Sta-Bil CLP on a patch,followed up with a dry patch.
1Bottom photo was before shooting new barrel 2 Top photo after shooting 12 shots 3 Middle photo last 9 shots of the twelve(smallest group was a different powder and bullet)
12 rounds 300 wm lr.jpg
300 wm lr.jpg



REM 300WM LR4.jpg
 
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All of my rifles have high-end, custom match grade barrels. Most of them need fouling shots before the groups tighten and POI is stabilized. This can easily be seen at 400yds. At 100yds, you may not see any difference. I have also noticed that heavy fouling can change the POI to a small degree. If you watch the initial chronograph numbers, the first shot is always the lowest and they will climb for at least 3 shots.

In my experience, 3 fouling shots are the minimum and some barrels benefit by 6 fouling shots. The pictures posted by baldhunter (above) look like a brand new barrel. None of the barrels that I have look like that for very long, even though they all start out that way.

I would love to have barrels that are as stable as those described by MagnumMania but they just don't exist in my world. It is interesting to learn how different everyone's experience can be.
 
I have about 90 rounds down my barrel now, last 3 shot groups, 1st was 1.120 second 3 was ,782 and 3rd was .375, not sure if it gets better with more shooting and fowling shots start to shrink , Pete
You're looking at way too small of a sample size. Not saying that some barrels don't need a few foulers, but think about it this way: if I shot 30 three shot groups from clean to 90 rounds without cleaning some are going to be way better then others. There might be a .2 group in there at shots 22 thru 24 and a .8 group at shots 37-39 and then a .3 at shots 61-63. You will drive yourself crazy trying to a see a pattern that isn't really there.
 
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