Setting Neck Tension for 6 dasher brass

[Jerry Snyder]

I have a nice set of Whidden dies with neck bushings. If I wanted to adjust the neck tension, do I need to have corresponding neck mandrels also? I have a neck mandrel 2 thou (241) smaller then the projectile (243), but have 6 different sizes of bushings. Any help would be appreciated. I am new to the mandrel/bushing game. Thanks

 

[JMayo]

I don't use mandrels. Unless it's dented i don't see the point.

 

[L.Sherm]

If you have good brass why use the mandrel to scar up the carbon inside the neck.
I should add as long as your bushing are nice and round on the inside and the size you desire.

 

[rlporter507]

no. you can just go with bushings if you have good brass, say less than .001 wall consistency. if you want to get more technical, you can neck turn and use a smaller bushing than you need, then use the mandrel to get the tenson you want. then the outside and inside are both round, depends on your goal for accuracy. If you want the inside of the neck round, then use a mandrel. if your happy with the inside a little out of round then a bushing is fine. using a bushing only if the brass neck is not a consistent thickness, will show up on the inside as out of round. If you anneal each loading you will burn off most of the carbon on the inside of the neck. if you dont anneal, the carbon will build up and at some point you will have to change the bushing to a larger one. you need a pin gauge to measure the neck insides, calipers really dont do a good job. something like this.

MATCH GRADE - Case Mouth and Neck Tension Gage 224 / 308

Match Case mouth gauge or gage for determining neck tension of 223, 5.56, 308, 30/06, etc. Match grade.

ballistictools.com

hope this helps you out.

 

[Rank Amateur]

Many in F-Class use mandrels to set “neck tension”. If you go that way, you want to do it in a way that minimized working of the neck brass. Choose a bushing that will leave the neck ID only a couple of thousandths under mandrel diameter. The mandrel will then only stretch out the brass a bit more than a thousandth (given spring-back in both directions after bushing and mandrel). If you clean brass in a way that removes neck carbon, you should lube inside the neck before inserting the mandrel to minimize galling. I only clean in vibratory tumbler, but still lube inside necks with Neolube before mandrel.

 

[L.Sherm]

I have a nice set of Whidden dies with neck bushings. If I wanted to adjust the neck tension, do I need to have corresponding neck mandrels also? I have a neck mandrel 2 thou (241) smaller then the projectile (243), but have 6 different sizes of bushings. Any help would be appreciated. I am new to the mandrel/bushing game. Thanks

I suggest you test both methods and decide for yourself.

 

[padom]

I use a bushing that sizes my neck 0.004 under loaded neck diameter then use a mandrel to open it up 0.002 for a final 0.002 neck tension. You can use different mandrels for different neck tension...