ALMOST NECK TENSION

John Alexander wrote: Joe, As you note FL sizing dies don't size every case to exactly the same headspace.Yes, the HS seems to vary over a range of .006"   So your idea of setting the headspace of the rifle on a FL sized case will not work part of the time. When the die sizes a case to a slightly longer headspace than the case you used for setting up the rifle it won't chamber as you have found out. Not true. I set the barrel with ~3-5 cases so the bolt closes without resistance. Then with 1 layer of Scotch tape on the head, look for a little bolt closing resistance, again ~3-5 cases. Then with 2 layers of tape, look for a lot of resistance. This is an analog, FEEL kind of HS setting. The FEEL of the bolt closing is over several thousandths of variation in case HS. I'd guess that the bolt can be closed, with resistance, on a case with ~.003” or more HS greater than the rifle HS. Means that long cases/short chambers still allow bolt closing without undue force required. I've never had ctgs that won't go in the gun because of HS.I have RCBS Precision Mic's for only 223 and 308, so only can talk about them. You are right FL sizing sometimes causes the headspace dimension to lengthen as the sides are squeezed in from their expanded dimension.  I have a set of dies that does that every time if you try to PARTIALLY FL resize.  Then they won't chamber even if the case was fired in the same rifle and the case would chamber easily before it was partially FL sized.Correct, sort of. During my testing I found that as the die was screwed in, to neck size in FL dies, there came a point where the neck was sized BUT case HS increased. I wondered if the BR guys “bumping the shoulder back” was about this. It seems to me that the simplest solution would be to headspace the rifle on a case that had been fired (but not resized) in a SAAMI chamber or set it using a headspace gauge. Then it would be very close to SAAMI headspace. I think that you rely too much on the factory. I spent a lot of time measuring fired brass at the range, and found that the factory HS varied all over the lot. Generally larger dimension than SAAMI. Somebody pointed out that HS gauges are made for NEW barrels/guns, and so are SAAMI specs. Wear then increases HS. So, your suggestion about a case in a SAAMI chamber-where do we get one? Then only neck size your cases by backing out the FL sizing die so it only touches and sizes the neck of the case. Before the collet die came on the market, I did all my reloading this way (except when I expected to find a grizzly and wanted the rounds a bit loose so they chambered easily).  After being fired once in your rifle your cases would then fit snugly as close to the exact headspace of the rifle as possible and would stay that way for many loadings at most cast bullet load pressures in a bolt action. My method of setting the gun up works for me. I've changed and shot a lot of Savage barrels now, FL size with my dies, sometimes neck size with Lee Loader, M die frequently, leave lube on the cases and don't get split necks. I'm working the brass a minimum. Think about my Lyman dies, some cases .011” shorter than Saami. Also, the Q tip + lube maybe? keeps necks from stretching?  I will save my suggestions for working the Collet die for another time.

John