January 04, 2011
Case neck lubrication is a necessary evil, but there are easy methods.
The best but also costliest solution to getting around neck lubrication is to buy a carbide expander for your die or buy a die so equipped. This one is from Redding.
When we run that little brass cartridge case through a sizing die we are subjecting it to a number of different stresses. We know, of course, that the body has to be shrunk a bit so it will go easily back into the chamber. Maybe the shoulder gets pushed back a little too, but we really do some stuff to the neck.
We are told that the inside needs to be lubricated just as much as the outside, but nasty old chemistry can prevent us from using the same lubricant for both jobs. The oily stuff that works just fine on the outside would be very bad if it came into contact with the powder and turn our firearm into a cap pistol.
The material of choice for this job is graphite. Since graphite is a normal component of smokeless powders this is an outstanding choice--were it not for the mess it makes. Reloaders from the beginning of time have worn indelible black on skin and clothing because of it.
Of the several ways to use graphite the handiest is a kit such as one from Redding that uses tiny ceramic balls about 0.050 inch in diameter in a plastic cup that looks like the film cans of days gone by. The ceramic's slightly porous surface is a great place for graphite to stick, and all you have to do is dip the case neck in it and you'll get just enough graphite to do the job. There are variations that use balls of different materials, and this is a much better arrangement than just loose graphite.
However, over the years, and as a result of having scattered graphite all over my bench, I've worked on methods to use to avoid inside neck lubrication at all.
Sometimes the best ways are the simplest and in many cases just using a brush to clean the inside is enough to take care of everything. I keep a couple of nylon brushes right by the press. I've found that this method is fine as long as the brass is in good shape and is relatively new.
Old brass that has work hardened by repeated sizing may resist, but I always try brushing the neck first. Kent Sakamoto at RCBS goes a step further and gives the brush an occasional spritz with Case Slick. Since it is a non oily lube and uses hexane for a carrier, it evaporates rapidly and doesn't cause any problems.
By far the best, but also the costliest, method for eliminating neck lubrication is to buy a replacement expander made of carbide. Just as carbide sizing dies for handgun cartridges have eliminated the need for lubricating those cases, the carbide expander eliminates the problem with bottleneck rifle cases.
All it is is a small ring that replaces the expander on the decapping rod. Most are free to "float" on the rod, which helps reduce stress as they center themselves in the case neck.
Sometimes simply polishing the original expander can work wonders, but it is also a somewhat risky job because tolerances on these parts are fairly close, and if you remove too much metal it may be difficult to seat a bullet.
If you decide to try polishing, chuck the expander in a drill press and run the drill at relatively slow speed. With a strip of fine emery cloth no wider than the area you want to polish, hold it like a shoe shine cloth and gently touch the spinning expander. Be careful because it is possible for the emery cloth to wrap up on the chuck and drag your fingers in if you don't turn loose fast enough.
There is a material called Cratex that is exceptionally good for polishing rather than removing metal. I put a Cratex wheel on a mandrel for the Dremel tool and with the original expander chucked up in the drill press, and both running slowly, it is possible to gently polish the expander. Once again, you really have to be careful not to get the two tangled up, but this method can give a very nice finish without removing too much metal.