OzFclass

williada wrote:Coming back to related area, in the ammunition neck. This sort of effects that neck tension. We all know that altering neck tension effects powder burn rates and pressures therefor group size. We all know that inconsistent neck tension is a big no no. Winchester demonstrated to me the actual benefit of sealant that in effect made neck pressure consistent, higher and prevented contamination of the powder by environmental factors. We can of course through reloading get a better result without the sealant. But we are not serving a mass produced market, where their testing and statistical solutions have minimised the problems associated with mass production.

I was looking at neck tension about 2 years ago as an extension of K&M's Arbor Press with Belleville washer stack and pressure indicator. The idea was to look at thin film (<1um) coating projectiles to maximise consistent seating forces, not necessarily for low friction or bore wear as is the case for the current moly, tungsten and HBN etc. type coatings. The coating would have to be completely consumed to avoid any possible build-up effects in the bore. The surface finish on the section controlling neck tension in the die; and the surface finish on the case neck ID/OD, would also have to be controlled. I've acquired some coating material to trial, but as always I've been working on other priorities first given the number of shooters out there that can measure and utilise the benefits is a relatively small percentage.

Aaron there is a relatively small percentage of people out there who would look at this. Back in the 1980's when buttoning some barrels the bloke I was working with used a Teflon mixture to lubricate the bore before the button was pulled through. It evaporated off leaving a thin film. A bit different to the process of a flash of electroplated copper as lubricant. After the barrels were finished, I ran some of this gear through again and they shot like crazy for about 50 rounds then fouled. What I believe was happening and it was confirmed by others experiences, that Teflon left in the bore with a similar process balls up and presents a problem as it is stripped from the surface by shooting. So after doing the barrel testing I realized I was barking up the wrong tree with a plan to use the teflon on the projectile and neck at one stage.

Yes the HBN and Moly have a different use context, and I think what you are considering has great merit if you look for the right substance that is consumed on firing. It reminds me of the old beeswax and castor oil methods.

Edit: I would hope no idiot would superglue the projectile and the case for consistent ignition. The results could be catastrophic failure.

David.