Neck Tension - adjust it when?

[dbshabo]

Been reading about the reloading process recently. I've come across some posts talking about neck sizing and the amount of tension the neck applies to the bullet. My question is what do you look for in the performance of your reloaded ammo that would indicate a need to make an adjustment to the neck tension of your rounds?

Shabo

 

[mdmp5]

It is very difficult to gauge performance of reloaded ammo based on neck tension. Generally speaking, more neck tension exposes the bullet to more runout. I try to keep my neck tension between .001 and .002, usually ends up being somewhere in the middle. With this method, I am able to load rounds with very little runout. You want to use as little neck tension as you can get away with, without the bullet swimming in the mouth.

 

[jkonzal]

Once you develop your load, you can play with neck tension to try to tighten up your group, but mostly to lower you SD/ES.

 

[bruddah]

This was a good question. I've wondered about this myself.

 

[2Shots]

Typically we look for about .002" crush from the ID of the case to the OD of the bullet. I start with that formula but usually use the sense of feel when you seat the bullet and look for smooth firmness but mostly consistency. The more consistent you are round to round the lower your ES will become, meaning your groups will tighten up. Problem is the more you shoot the cases the more hardened the brass gets so they start to vary slightly, now that leads to annealing them all. See what we mean, its all tied together, but the key is consistency. We don't know your rig or your load or your reloading techniques so you might need to start somewhere else first. Just curious what kind of accuracy are you getting now, is it not good enough for you? Do you need to change things?

 

[dbshabo]

Thanks to all for the replies. I'm working up a load for a 6.5 Creedmoor rifle. I'm in the process of determining how far from the lands to seat the bullet. I've got some good groups (about 1/2") at 100 yds with three different loads. I'm gonna load them again and see what they'll do @ 200yds.

I was just curious about the neck tension thing after reading a few posts mentioning it.

Shabo