Cleaning/Accuracy

[charlie b]

I am also a mechanical engineer with a little metallurgy experience.

A 'clean' rifle barrel is kind of an oxymoron. Once bullets are fired then erosion begins, especially in the throat. Added to that are the tooling marks left by normal production processes. So, there is rarely a clean, smooth surface for the bullet to travel through (hand lapped custom barrels are better in this regard). If you really want to see how bad it is get a good borescope and look into a bore. Also, let's consider that cleaning with many solvents just removes powder fouling and leaves copper in the bore. To remove the copper you need to use a product that will do that.

So, what we look for is consistency and that may be different if you are a hunter or paper shooter. As a hunter I used to sight in barrels by cleaning well between each shot, presenting a bore that will be the same when I take that first shot. Yes, follow up shots are done as well, just in case, and any POI change was noted between clean and fouled barrels. For paper punching I shoot a couple of shots before going for a bullseye to make sure that the record shots are on the same kind of conditions.

Also consider what happens in the bore. The first round will encounter only whatever lube you left in the barrel. Following will have burned powder and copper residue to deal with. That residue will partly be expelled by the next bullet and partly 'ironed' into the pits in the bore. Some will claim that enough of this makes the bore 'smooth' by 'filling' the pits and is good for the barrel. If you look at some of the data taken by precision shooters they have plotted group sizes based on how many rounds they have fired since a cleaning with copper removal. There is a definite change with the number of rounds fired between cleanings with copper removal.

So, all that is why some people clean a lot and some don't clean very much. One other factor is that very frequent cleaning may cause more barrel wear than shooting due to the cleaning rod rubbing on the bore. Hunting rifles that are fired only a few times between cleaning are probably worn more by the rod than the bullet. Some precision shooters will clean often and just replace the barrel more often. Some of those may replace a barrel every year or even sooner depending on the cartridge they are shooting.

[CFJunkie]

I appreciate the expertise of azguy and charlie b and believe they are both right.

I find that shooting from a recently cleaned barrel results in one or more rounds off the POI.
Then after the cleaning residue is eliminated, the POI is right on and the rifle is back to its normal accuracy.
Most of my rifles shoot the first round or three high then the POI drops to the POA.
I have one rifle that does the opposite - go figure.

As I said, I generally shoot 75 to 100 rounds with each rifle I bring to the range on any given day.

With that amount of use, I am a great believer in cleaning rifles after every use and removing copper. I never use a brass brush and rarely use a nylon brush.
Because I clean each barrel so often, I use either Wipe-out foam or Patch-out fluid on a patch because they are not harsh but take out the copper very effectively while they clean the barrel.
I only use the foam on higher calibers because I find that the nozzle on the foam doesn't make a good connection to the chamber on calibers under .308 and often foam comes back into the action.
But the foam does wonders cleaning out flash hiders and muzzle brakes on my .308s.

The first patch through the barrel after putting the foam or fluid into the barrel and waiting at least an hour comes our deep blue from the copper removed.
The barrels are clean - nothing showing on the patch - after about 8 to 10 patches depending on the number of shots fired.

As for barrel wear, I have over 4100 rounds through my best shooting Savage 6.5mm Creedmoor and 3600 and 3900 respectively through my to .308 Savages without any drop off in accuracy. In fact, over the last three years each of the three rifles have shot more accurately every year, probably because I concentrated on improving my shooting and reloading techniques for the past three years.
I admit that I did wear out my first Savage .308 after over 6,500 rounds but that was primarily because the chamber that came from the factory at 0.080 longer than SAAMI.
The 6.500 rounds eroded the chamber another 0.090 deeper and I had finally had to seat out so far to maintain the jump to the rifling that I was losing consistent neck tension.
All of my new Savages have come from the factory with chambers right at SAAMI so I figure I may have an extra 5,000 rounds of erosion available to wear before I have to replace those barrels.

[Newtosavage]

I'm not an engineer, but my gut tells me you either want a clean barrel, or a dirty one. I can see both arguments. I've always read that the value of a fouled barrel is that the fouling will "even out" the rough surfaces in the barrel. I know that from a precision engineering standpoint, this probably makes some people's skin crawl, but from a practical standpoint it makes a lot of sense to me.

I know I didn't see the best accuracy from any of my factory Savage barrels until they had at least 50 rounds through them and in two cases, nearly 200 rounds. I was ready to give up on a barrel once that would do no better than 1.25" for the first year I owned it. But after about 200 rounds, it would do no worse than an inch and often much better.