It has to be lower pressure and thats a sooty powder. Maybe just a change of a hotter primer or a little more powder will improve the neck problem. But it's only cosmetic. You can wipe the necks with some product.
Generally, a little soot on the case neck is nothing to be concerned about. However, I have a rifle that during load development had soot about 1/3 the length of the case, way beyond the shoulder. A switch to a magnum primer with the same powder load remedied this. Soot of any kind means that there is not a perfect gas seal over the full length of the case. I've found it's pretty common to have some soot on the necks. I don't worry about it as long as the load shoots well.
Ryan
Posts: 425 | Location: Minnesota, USA | Registered: 01 April 2001
It is possible to get conflicting signs so don't take sooty cases as a gospel sign of lack of pressure. As speer say in their manual these things are best thought of as 'often but not allways'
Posts: 2258 | Location: Bristol, England | Registered: 24 April 2001