If fired cases are neck sized only, and they retain low to no runout, which they should, and there's enough headspace, load 'em and shoot 'em.For testing purposes? Or are you suggesting he neck size his brass?….
Wayne
If fired cases are neck sized only, and they retain low to no runout, which they should, and there's enough headspace, load 'em and shoot 'em.For testing purposes? Or are you suggesting he neck size his brass?….
Wayne
Idk what he’s doing but the key to accuracy is consistency and you can only be consistent f/l sizing the same every time. Eric Cortina proved for FClass accuracy which is less than benchrest but still accurate, he saw no difference in runout up to I believe.008 but I might be wrong on the number but it was a bunch. Neck sizing is old school short range benchrest and even they abandoned that years ago.If fired cases are neck sized only, and they retain low to no runout, which they should, and there's enough headspace, load 'em and shoot 'em.
Agreed. But it will help to isolate low to no runout as an objective in order to assess it's value. I've long ago given up on runout; it's a difficult control value, and a debatable result value.Idk what he’s doing but the key to accuracy is consistency and you can only be consistent f/l sizing the same every time. Eric Cortina proved for FClass accuracy which is less than benchrest but still accurate, he saw no difference in runout up to I believe.008 but I might be wrong on the number but it was a bunch. Neck sizing is old school short range benchrest and even they abandoned that years ago.
Wayne
10-4Agreed. But it will help to isolate low to no runout as an objective in order to assess it's value. I've long ago given up on runout; it's a difficult control value, and a debatable result value.
I will tell you how to get excellent runout. Use a one piece die made or modified so that the ID of the die's neck is correct for the application. You can get this by ordering a custom die, or lapping out the neck of a factory die. There is a really good article on how to do this and where to buy the tool. I passed it on to a friend and he was able to achieve excellent runout and improved accuracy for a .264 Winchester. Bushing dies do not work well when you need to reduce the diameter of a fired case neck as much as many situations require, but a properly dimensioned one piece die will.Agreed. But it will help to isolate low to no runout as an objective in order to assess it's value. I've long ago given up on runout; it's a difficult control value, and a debatable result value.
LOL I was just posting the similar thing. See above.I will tell you how to get excellent runout. Use a one piece die made or modified so that the ID of the die's neck is correct for the application. You can get this by ordering a custom die, or lapping out the neck of a factory die. There is a really good article on how to do this and where to buy the tool. I passed it on to a friend and he was able to achieve excellent runout and improved accuracy for a .264 Winchester. Bushing dies do not work well when you need to reduce the diameter of a fired case neck as much as many situations require, but a properly dimensioned one piece die will.
If your putting lube on your shoulders you will not get consistent shoulder bumpUPDATE: So this is my process to get .001 or .002 runout of once fired brass, Clean and anneal. The next day position the Fl bushing die the best position for headspace. Measure the neck of fired case for mine its .295. Next I put in the bushing I have .294 and lube the case liberaly with imperial sizing die. The first time through the die its a bit hard to push down as the body is being sized. Once I remove the case I notice that the case shoulder has grown out. This is ok as Im going to put through the die a second time but with bushing .292
Then finally the .290. I measure the neck and its .289 exactly what I want. I measure the runout and its .002. I measure with my precision MIC and its perfectly where my headspace number for my chamber is.
I did it again for another case and this time .001. I haven't put through the mandrel yet but from experience the runout value stays the same.
Very happy but a lot of work for one case.
Somewhere between the amount of lube you are using now, and so much lube a dent is formed in the brass, is probably your answer.EUREKA!!!!!!
Lubed liberally the case with imperial sizing wax and and first case since the die was so clean was a bit hard to go through so before measuring I decided to do another case same again with lots of lube and this time it was much easier.
SO I measure both cases the first one had .002 then the second was .001 THIS IS AWESOME I FOUND THE REASON FOR RUNOUT! I feel also if the case is well lubricated and it goes easy in the die (not make noise) then the runout is much less.
I will give it a try...an let you know.Can you answer my question from post 7, it could save you a lot of time,frustration.
I get the glass feel on the second stroke. The first stroke no matter how much lube I put (imperial) is a bit hard as its sizing the body. (Its not the sound more of a harder up stroke to get the case up into the die. This happens on all once fired case I put first time into the die.) I can see evidence of this when I first measure head space before I put the case in die then measure after the first stroke, it has grown, the shoulder has move .004-.005 longer. Then after the second time in the die it brings the shoulder into spec and this second time feels like glass smooth.Somewhere between the amount of lube you are using now, and so much lube a dent is formed in the brass, is probably your answer.
If you can feel a chatter when sizing the case, it’s not enough lube. If you are getting noises, you are close to disaster by sticking a case in the die.
The resizing stroke should be relatively easy, and as smooth as glass.
Hopefully you’re on the way to perfection!
About the only way this can happen, is if the case is not completely entering the die the first time. Check the space between the bottom of the die and the shell holder. There may be a gap the first time, and none then second time, or just more the first time. You could check that with a feeler gauge. The die is not touching the shoulder on the first size, so the difference is a bit more that what you measure.I get the glass feel on the second stroke. The first stroke no matter how much lube I put (imperial) is a bit hard as its sizing the body. (Its not the sound more of a harder up stroke to get the case up into the die. This happens on all once fired case I put first time into the die.) I can see evidence of this when I first measure head space before I put the case in die then measure after the first stroke, it has grown, the shoulder has move .004-.005 longer. Then after the second time in the die it brings the shoulder into spec and this second time feels like glass smooth.