Re: NEWER SUBJECT: Can cold bore zero errors be .
Have used alcohol. But latest mix is Hoppe's oil, Acetone, and Graphite. Acetone evaporates, leaving a light oil coating that helps bind the graphite.
I tried moly, and then realized that dry bore lubes have been a regular part of shooting for well over a century. The dry lube is graphite, it is present as a propellant granule coating/static charge deterrent, and has been so since around the time smokeless powder was introduced. Its primary purpose is as an electrical conductor, equalizing static charges within the mass of propellant before it can build up to cause a static discharge that ignites the mass. Thank graphite for the convenient fact that propellants may be safely shipped via conventional commercial transportation. The 'carbon fouling' most of us cuss at is primarily composed of unburnt graphite residues from those coatings. It coats the bore with a layer of dry lubricant, and is one of the reasons velocities alter after the first few shots out of a CCB.
Treating bullets and bores with moly is rather a bit redundant, IMHO, and preconditioning a bore with graphite simply parallels the process many moly shooters often use.
There is a lot of knowledge being presented on this site that CCB POI deviations are more the result of a cold shooter than of a cold, clean bore. I think they are absolutely true, as long as one understands that cold, dry bores <span style="font-style: italic">do</span> affect the velocity of the initial shot(s). Whether these velocity variances consequently cause a different POI is rather more a factor of the load's relationship with the barrel's accuracy node; and whether or not the two velocities (cold/dry, warm/fouled) inhabit the barrel's accuracy node velocity range.
If they do, it's all about the shooter. If they don't, there is an additional factor.
In this case, it may pay to alter the powder charge slightly up or down, to see if the cold, clean and warm, fouled velocities can be brought into line with a (more) common POI
I had, at one time, considered that a barrel tuner could be used to alter harmonics to aid in this, but soon discovered the tuners caused more problems than they solved. Once tuned, they can induce amazing accuracy; but once conditions like ambient temperature alter, they need to be retuned.
The net effect is a rifle that goes out of tune every time the weather changes significantly. Better to live within a larger, more stable accuracy bubble, than to chase a tiny one incessantly. This is why BR shooters are always tweaking their loads throughout the duration of the match; they are chasing that tiny bubble. With time, they become adept at matching tweaks to temperature charges. Logically, a tuner could be used the same way, but I found it just a case of too too many shots and too much time; and all I was accomplishing was to substitute constant tuner manipulation for a one-time load development cycle.
Greg
