Hi Horseman,
I wonder if the variability between rifles comes from the process they use to put the rifles together:
If the bolt extractor hole and channel is milled into the bolt head and THEN the barrelled action is correctly head-spaced by milling material out of the bolt face then this would account for the variability in how well the extractor holds the cartridge case and the variability between rifles.....back to bell-curve distribution.
i.e. good design with incorrect implementation - probably to save money.
Hence what I believe should be done which is the requirement to adjust each extractor to each rifle. This could be achieved by my method (crude but effective), or better still, having a range of extractor sizes and fitting the correct size to each bolt ....AFTER it is head-spaced.
....food for thought.
