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