+- .004 Neck tension too much?

[Wrench]

If you are worried, the lee collet die is a fantastic sizing die. It squeezes onto a floating mandrel that will always be centered.

But no, .004 is not too much. The issues will be work hardened necks, internal scratches and inconsistent tension due to brass thickness.

 

[tdot]

My understanding of "cold weld" is that it takes place over a considerable time, not just days or weeks. But I have never experienced it, and that includes loaded rounds from 4 years previous. So I doubt I'm any help.

 

[TimberHunter]

My understanding of "cold weld" is that it takes place over a considerable time, not just days or weeks. But I have never experienced it, and that includes loaded rounds from 4 years previous. So I doubt I'm any help.

Have you shot ammo you have loaded the same day and recorded the velocity? Was the velocity different (lower?) from ammo you’ve loaded and then shot several days/weeks/months later?


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[tdot]

Have you shot ammo you have loaded the same day and recorded the velocity? Was the velocity different (lower?) from ammo you’ve loaded and then shot several days/weeks/months later?


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Didnt reload a matching load.... but my velocity was very close to what it was 4 years previous. I also tore apart one of the rounds as I was curious to see if any of the powder had stuck together. The bullet came out easily without any unusual resistance.

 

[recurveman]

Your velocity change isn't going to be from a "cold weld". I've shot ammo years and years later and it is basically the same speed. I've never had a change at all with ammo I've loaded in the last few weeks/months. My best guess would be a change in your loading. Maybe your scale wasn't calibrated both days and causing a different weight charge? Could it have been your chrono? It had an error for one of the other speeds so maybe it wasn't performing great at that time. Same can of powder? Powder will change by a bit from can to can. I only buy large amounts of powder at a time.

What did you change between the two loads? Seating depth? That will change velocity and pressures by quite a bit at times.

Were the brass all from the same firing? Was it the first firing? second firing? Third? When I load brass I will basically do all the work to the THE ENTIRE LOT of brass except the mandrel, powder, bullet. Even if I'm not going to load the brass for a few days, weeks, months. I will size the brass, primer and anything else I'm going to do to the brass. Then I have a consistent set of brass to work from when I put powder and bullets into them.

 

[TimberHunter]

Your velocity change isn't going to be from a "cold weld". I've shot ammo years and years later and it is basically the same speed. I've never had a change at all with ammo I've loaded in the last few weeks/months. My best guess would be a change in your loading. Maybe your scale wasn't calibrated both days and causing a different weight charge? Could it have been your chrono? It had an error for one of the other speeds so maybe it wasn't performing great at that time. Same can of powder? Powder will change by a bit from can to can. I only buy large amounts of powder at a time.

What did you change between the two loads? Seating depth? That will change velocity and pressures by quite a bit at times.

Were the brass all from the same firing? Was it the first firing? second firing? Third? When I load brass I will basically do all the work to the THE ENTIRE LOT of brass except the mandrel, powder, bullet. Even if I'm not going to load the brass for a few days, weeks, months. I will size the brass, primer and anything else I'm going to do to the brass. Then I have a consistent set of brass to work from when I put powder and bullets into them.

The scale should’ve have been calibrated correctly both time and at most, maybe .1-.2 grains different which would only amount to 20 or so FPS difference. Same lot of powder, same lot of brass on their second firing. Only thing I can think of that may have been different is the should let on the cases from 4 days ago may have been .002” different (shorter) than the ones I loaded the day I Shit them


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[wind gypsy]

Only time I’ve had them get slower is if rounds were loaded with “fresh” powder, powder was left in the hopper during high humidity conditions for days and then more ammo was loaded. Humidity seemed to have reduced the powder burn rate and resulted in slower ammo.

 

[Wrench]

Don't forget that lot to lot variations are real.

 

[dla]

I tried to read through the thread, so I apologize if this has already been touched on.
(1) whenever you move the shoulder, the case length increases.
(2) You can neck-size only. Much easier. Sounds like you shoot well enough to do an accuracy test.
(3) WWII 30-06 ammo was sealed with tar - essentially gluing the bullet in place.

 

[rayporter]

take one case and shoot it 3 times with a stout load save it. mark it as your chamber length.
try to neck size only so it really fits tight.

I make several hundred cases a year and sometimes it can take 4 shots to hammer a case out to fully fit the chamber, especially if loads are not real hot. temperature of the barrel and dies and chamber and the outside air can affect how the cartridge fits the chamber. when you are trying for a perfect fit in the chamber you can feel the little differences as the bolt closes.


also chasing runout in a factory chamber will probably be futile.

 

[rodell]

No. .004” is not too much tension.

Consistency is more important than the exact number. Don't forget that freshly annealed brass is softer, too. Also consider how much "tension" is created by factory crimps.