I have some well used brass - 308 Lapua and Lake City LR and 300 Win Mag Navy WW and Lapua. I did not turn the necks. After many firings, the neck thickness is not consistent from the top to the bottom of the neck. When I seat, bullets start smoothly then I push past a "ring" where the neck is thicker then the bullet slides with less friction.
It seems to me that the bullet is not supported by the whole neck but mostly by this ring. The parts of the bullet cylinder above and below the ring are not actually in contact with the bullet. Since the necks are not consistent from top to bottom, as a round feeds from the magazine the bullet could become slightly canted and this might be bad.
It just occurred to me that I could test this theory by shooting groups at 500 - some from the magazine and some hand-fed. Never mind. The question continues ...
As an associate member of the "hand loaders with OCD" group, I am thinking that maybe I want to fix this. So I came up with a plan. Suppose that I start by annealing then size my brass. That makes the neck outside diameter the same from the top of the neck to the bottom and it pushes the ring into the ID. Then I screw in a neck expander mandrel and run the necks over that. This makes the ID the same (more or less) and pushes the ring to the OD. Then I turn the necks thus cutting off the ring. The cut would leave the neck thickness as large as possible - more brass means more support.
1. do you know - or think that you know - that the ring is a problem? For what it's worth, I am not yet convinced that it is.
2. will this procedure actually cut off the excess brass that makes the ring? For example, maybe the mandrel temporarily pushes the ring but then it springs back ... or something.
3. aside from the time and cost it takes to do it, is there any downside you can see? Except for custom mandrels I have all the tooling I need to do this.
4. do you think that I will be able to see results on the target? Will it generally reduce group size or eliminate flyers? Both? I am inclined to think groups will remain the same but I will shoot fewer flyers.
5. suppose that I don't do this. If I start with new brass, is there a procedure that actually prevents the ring?
6. suppose that it helps, will the benefit be close in but not downrange? Downrange past 800 but not noticeable under 500?
7. screw this, yer wasting yer time ya moron, just go and shoot?
It seems to me that the bullet is not supported by the whole neck but mostly by this ring. The parts of the bullet cylinder above and below the ring are not actually in contact with the bullet. Since the necks are not consistent from top to bottom, as a round feeds from the magazine the bullet could become slightly canted and this might be bad.
It just occurred to me that I could test this theory by shooting groups at 500 - some from the magazine and some hand-fed. Never mind. The question continues ...
As an associate member of the "hand loaders with OCD" group, I am thinking that maybe I want to fix this. So I came up with a plan. Suppose that I start by annealing then size my brass. That makes the neck outside diameter the same from the top of the neck to the bottom and it pushes the ring into the ID. Then I screw in a neck expander mandrel and run the necks over that. This makes the ID the same (more or less) and pushes the ring to the OD. Then I turn the necks thus cutting off the ring. The cut would leave the neck thickness as large as possible - more brass means more support.
1. do you know - or think that you know - that the ring is a problem? For what it's worth, I am not yet convinced that it is.
2. will this procedure actually cut off the excess brass that makes the ring? For example, maybe the mandrel temporarily pushes the ring but then it springs back ... or something.
3. aside from the time and cost it takes to do it, is there any downside you can see? Except for custom mandrels I have all the tooling I need to do this.
4. do you think that I will be able to see results on the target? Will it generally reduce group size or eliminate flyers? Both? I am inclined to think groups will remain the same but I will shoot fewer flyers.
5. suppose that I don't do this. If I start with new brass, is there a procedure that actually prevents the ring?
6. suppose that it helps, will the benefit be close in but not downrange? Downrange past 800 but not noticeable under 500?
7. screw this, yer wasting yer time ya moron, just go and shoot?