Thread: Your view on copper in a bore

is it fouling?

or is it helping?

For a while I have been trying to get my my head around if copper lining is bad or good.

Now when I read and over-hear experienced target shooters say that the first shot of a clean barrel is 1/4 or even 1/2 MOA lower than all the next shots, that tells me there is something I at least dont understand is going on.

For instance Ive been reading some advanced tribilogy papers (the study of friction and lubrication) suggesting that for high speed and low load bearing surfaces that the copper, for a fraction of a second turns liquid at the boundary layer thus reducing friction and drag on a bullet as it passes down the bore. So in a clean barrel situation dropping 1/4 or 1/2 MOA as above is explained.

Of course this may not be the proper reason.

any other ideas?

All else being equal, ie after 60~200 shots (depending on a gun) a bore losses accuracy, hence that suggests there is a "sweet spot" ie between too clean and too dirty.

regards

Subscribed, this should be good!

Personally, in my Tikka M595 .243 I don't use copper removing bore solvents. I just patch out till clean, with some ballistol towards the end of the process. This has been the process for this particular rifle since new 13ish years ago. Admittedly, around 3 years ago I did flush it with some bore-tech, but won't bother again as there was no noticable difference.

Accuracy is brilliant but only up until around 15 shots. After that, groups open up considerably, and fast. A couple of patches and carry on. I guess my window is smaller than most?

Interested to hear what others have experienced too!

its both fouling and helping

my take on it is, the first clean shot can be like a car with bald tyres. no traction
after that the bullet has some traction.
but as you keep layering the fouling down the bore, the bore is basicly getting smaller and smaller as the fouling builds up. and your loosing your accuracy as everything tightens.

all barrels are different too. fouling at different rates, and different amounts of copper and powder. just learn to read your barrel.

To quantify this i don't shoot shitloads haven't worn out a hundred barrels etc

But I have had a few rifles/barrels that have copper fouled to varying extents.

I mostly shoot groups developing a load then just use it for hunting with the occasional zero check and gong bash thrown in(not much shooting for the fun of it)
My rifles always get a wet patch of hoppes or clp down the bore if they have been out fired or not s/s or blued,while not a full "clean" both products have a very mild copper removing action and wipe out loose carbon.
Dry patch before going out.

case one, shot very very well, would always streak the lands first shot (even with different projectiles)visible at the muzzle with the sun behind your shoulder looking into the first inch of muzzle.
It took 150-200 rounds before accuracy noticeably decreased and needed a full clean out.

case two, heavier copper fouler,would foul the bore as well as the lands,shot pretty well with bullets it liked but it didn't like many that I did. From dead clean it would shoot 25-30 rounds before it went pear shaped and point of impact would change the whole way threw the process.
I tryed JBs bore paste which seemed to make it worse for a start then settled back to the same as before.
I did find that if after a full clean I fired 10 or so blanks(full case trail boss with patch on top) to layer the bore with carbon, copper fouling was substantially reduced compared to shooting from clean.

Case 3 Copper foules like all hell! I wouldnt be suprised if all that comes out the end is the lead center
Cant comment on accuracy its got battle sights and my ability with these is probably about the accuracy im getting anyway and its only got 50 or so rounds down the tube so far.

Most of my guns no issues at all,
Had a gun the same as VC"s case 2.
After 20 rounds accuracy was shit.
Shot well off a clean bore.
This gun would go from 3 inch groups at 1000yards two all over the hill
Clean the copper out and away she goes again.
Some guns it's an issue some none at all.

I figure its a bit of both as well. Its an aid to a certain point and then the barrel suffers from "fouling".
And as with reloading its not specific to make, model or calibre. Some are more fussy than others.
Ride em hard and put em away wet until they start acting up. Unless they've been exposed to the elements.

If you want to keep hitting shit it pays to do a full copper clean. I can get around 150-180 rounds through the 223 but then it starts going off. Off equals misses.

I'm not pedantic/anal/fussy as a lot of people and haven't shot much for a while now due to circumstances BUT what works for me is when punching paper with either my Sako 75 S/S 308 or CG blued 6.5x55 is run copper remover until pads are clean followed by a lube for storage. When out for a hunt, punch a bit of paper to get the feel and leave barrel fouled for hunt. Bang flop every time. A good clean and lube when I get home till next outing

Shooting black powder, we always fire a fouling shot before competition begins, first shot out of a clean barrel is a flyer, no cu jackets just soft lead projectiles, get about 25 rounds out of the cartridge gun before it loses accuracy

With the .223's I've found it pays to put a few foulers through if your shots really have got to count.