Neck tension, (interference)?

[6pakzak]

My last step before loading cases has been to use Lee lube inside neck and run mandrel through it, then I leave it in there and primer, powder and seat bullet. Doing this I found my seating to be more consistent meaning that they all seat close to the same mark on my micrometer on seating die. I just added another step which is to brush out Lee lube after mandrel and reapply it cause I figured it would be more evenly applied than just leaving what's left after mandrel, I loaded 25 rounds yesterday doing this and found that the bullets would all end up at the same setting on micrometer, not just close, a couple were off but only by .0005, is this an indication that my neck tension is consistent? If not how would you tell?

 

[Mikecr]

It's an indication that your seating friction is way lower.
With less seating force there is less stem wedging, so less stem wedging variance.
It means nothing about tension.

You may be ok with this provided your either single feeding or the gun's recoil is very low (with magazine loading).

 

[6pakzak]

It's an indication that your seating friction is way lower.
With less seating force there is less stem wedging, so less stem wedging variance.
It means nothing about tension.

You may be ok with this provided your either single feeding or the gun's recoil is very low (with magazine loading).

I ran them in my AR15 and checked length of rounds in magazine as I shot and they stayed the same, should I have in loaded one from chamber and checked that too?

 

[6pakzak]

I ran them in my AR15 and checked length of rounds in magazine as I shot and they stayed the same, should I have in loaded one from chamber and checked that too?

On loaded not in loaded

 

[Mikecr]

Cycle a couple rounds through from magazine to dirt and re-check em.
An AR15 doesn't recoil much, but it's fast chambering could be a challenge for your desired bullet seating.

 

[6pakzak]

Cycle a couple rounds through from magazine to dirt and re-check em.
An AR15 doesn't recoil much, but it's fast chambering could be a challenge for your desired bullet seating.

If it does move do you think light crimp by Lee factory crimp die or should I try to increase tension

 

[Mikecr]

Tension matters less with a wet lube between bullet and neck, because that suspension prevents normal/further grip.
Crimping may be needed to hold bullets through handling/chambering/recoil.

I recommend dry lube or the provided carbon layer from firing.
There is at least a solid layer to grip.

 

[6pakzak]

Tension matters less with a wet lube between bullet and neck, because that suspension prevents normal/further grip.
Crimping may be needed to hold bullets through handling/chambering/recoil.

I recommend dry lube or the provided carbon layer from firing.
There is at least a solid layer to grip.

I was using dry lube, I'll go back to that, thanks.

 

[Mikecr]

You did get to see for yourself that lower seating force = consistent seating. What also follows this is actual neck tension.
I capitalize on this for most cartridges by setting neck interference at 1thou, which is barely more than natural spring back (~1/2thou), reducing the up-sizing effort with bullet seating and reducing tension variances. And I always leave the carbon layer in necks, with just a quick nylon brush-through.

 

[6pakzak]

How can you be sure you have the same amount of carbon build up in the necks, I usually ultrasonic clean and then tumble so I'm thinking the ultrasonic cleaning is cleaning the carbon out of the necks, I run a .223 mandrel as last step and lube inside of neck with lee lube before I do that and now brush it out after mandrel with brush on drill, do you think that is enough to get lube out? I just thought if you start with a clean case everytime you're starting with the same brass condition everytime. Should I bother with dry lube after brushing out lee lube cause there's probably some residue if it in there, and to be clear lubing with the lee lube before seating is no good?

 

[QuietTexan]

Did you watch the AMP Press demo video? It shows actual seating force traces of difference case neck situations. Simply brushing dirty necks makes a surprising difference and can result in very impressive consistency in seating force. I like the AMP in that you can see the full trace, with my K+M Force Pack I have to watch the gauge and try to take notes on what happens.

First three minutes show dirty and brushed case differences:


I haven't had time to do it yet, but I have a plan to test consistency of seating force for different case neck situations - annealed, dirty, brushed, wet cleaned, dry tumbled, etc - I want to actually see what the consistency in results for different processes is.

 

[6pakzak]

Did you watch the AMP Press demo video? It shows actual seating force traces of difference case neck situations. Simply brushing dirty necks makes a surprising difference and can result in very impressive consistency in seating force. I like the AMP in that you can see the full trace, with my K+M Force Pack I have to watch the gauge and try to take notes on what happens.

First three minutes show dirty and brushed case differences:


I haven't had time to do it yet, but I have a plan to test consistency of seating force for different case neck situations - annealed, dirty, brushed, wet cleaned, dry tumbled, etc - I want to actually see what the consistency in results for different processes is.

So basically if it works for you then use whatever method it is.

 

[6pakzak]

So basically if it works for you then use whatever method it is.

So is using Lee lube before seating making it so I cannot get enough bullet grip regardless of tension.

 

[6pakzak]

Also, it seems clear that I need some sort of release agent on the inside of neck whether it be carbon left or dry lube, if I sonic clean I remove carbon or as some pin clean that would also remove carbon, so as I asked before is brushed out Lee lube good as it will leave some residue or should I get it all out with sonic cleaning, anyways what would u use?