Neck Tension Issue

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:confused:I am new to neck tuning and was wondering why I get different neck tension out of my brass after neck sizing ( with a Redding die ). I can slip some bullets into the case by hand while others go in tighter? I tuned the necks after firing. I am using a Sinclair NT1000, I called them and they said I didnt have to use a expander and I should tune new cases but it does not matter if the cases have already been fired. Sinclair said that the tool I have is a older model and they didnt have the expander at that time all it does is make it less labour intensive when tuning.I tune all the cases to the same dimension, just enoungh to uniform them or if you like clean them up. I am shooting a 6mm Remingtion factory chamber. Hope some one can help?
 
If you turned the necks after firing it would make a definate difference. First, if your chamber neck is round the outside dimension of the brass will be round as well and the thicknes variations will be on the inside of the neck, best removed with a reamer in that case. Second, the neck diameter will be larger than ideal.

In short, you can turn after firing, but re-size first.
 
You are wasting your time neck turning for a factory chamber. Unless you are into a full custom brenchrest gun with a tight nech chamber, I doubt you will find any benifit in accuracy with neck turning.
 
You are wasting your time neck turning for a factory chamber. Unless you are into a full custom brenchrest gun with a tight nech chamber, I doubt you will find any benifit in accuracy with neck turning.

X2! Unless you have a batch of brass with terrible uniformity, [I would discard such brass] no gains are likely in a factory chamber. Quite often with the 6mm Remington, turning the necks causes the condition you describe, since many dies seem to size the 6mm Remington a minimum amount to start with. I have had brass lots that when sizing them, the expander button did not touch the neck after FL sizing. Regards, Eagleye.
 
The rule of thumb is that you don't need to turn the necks if your runout is within .004", and then just turn to trim off the high spots. As Maynard said, the advantage of turning with a factory chamber is of questionable value.

Variations in bullet pull weight are a related but separate issue, and to uniform your bullet pull weight there are a number of things you can do. Use the Sinclair neck expander to slightly oversize the neck, then use a bushing die to size it. Bushings are available in a broad range of sizes. To determine the correct one, add the neck thickness X 2 to the bullet diameter to determine the correct bushing size. Anneal the case necks after each firing. Work up you loads with the bullet seated into the lands. This eliminates the issues related to variations in bullet pull weight. Some folks claim that better accuracy is observed when you seat off the lands, that is only true when you want to achieve the highest possible velocity as in the case with hunting loads. Once the maximum load has been determined with the bullet seated into the lands, you can work backwards to find the best accuracy.

If you are loading hunting bullets with cannelures, crimping the bullets in place also uniforms the bullet pull weight, and allows the round to be chambered from the magazine. Some folks don't have an issue crimping bullets without cannelures, but I prefer to choose those bullets for target shooting applications and seat them into the lands.
 
Thanks guys that solves alot of do it this ways and do it that ways told to me by others. Also it makes a whole lots of sense to tune non fired. Thanks again!!!
 
neck tension is an interesting variable for accuracy, but one not usually experimented with.

After you have what you consider a good accuracy load, try neck sizing the cases with a conventional neck sizing die (or a backed-out FL die) with no expander button. This will make neck tension very high. In 308 I have found that this makes groups even smaller.

Try it.
 
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