Doesn't matter what I do... Neck Tension Variance

[Webster]

I anneal with AMP every firing, I use good brass (Peterson, Lapua, Alpha), my primer crush is about 6 to 9 thou, use good bullets (Berger, Barnes, Nosler), good dies (SAC), T7 press, I have tried with and without mandrel.

Doesn't matter what I do, I can't get a consistent neck tension. I have even trimmed all using Giraud trimmer and have about 3 seconds of dwell time in the press.

Is it just the nature of the brass, doesnt matter what I do, I will have certain percentage of cases will never be consistent?

What else am I missing? How do you keep you neck tension consistent?

TIA for your replies.

What do you mean by primer crush?

 

[DLT]

Do you tumble after you anneal? I flame anneal and have noticed I get some “sticky seating” on cases if I do the tumble after annealing. I am dry tumbling with corncob.

Did you mean if you “do” the tumbling or “ do not” after annealing?

 

[Superjet]

Did you mean if you “do” the tumbling or “ do not” after annealing?

I tumble before and after annealing.

 

[Straightshooter1]

I anneal with AMP every firing, I use good brass (Peterson, Lapua, Alpha), my primer crush is about 6 to 9 thou, use good bullets (Berger, Barnes, Nosler), good dies (SAC), T7 press, I have tried with and without mandrel.

Doesn't matter what I do, I can't get a consistent neck tension. I have even trimmed all using Giraud trimmer and have about 3 seconds of dwell time in the press.

Is it just the nature of the brass, doesnt matter what I do, I will have certain percentage of cases will never be consistent?

What else am I missing? How do you keep you neck tension consistent?

TIA for your replies.

Hmmmm??? How do you measure your neck tension? And how much variance are you getting?

I think you might solve it by turning the necks???

 

[Webster]

Seating force and neck tension ( bullet hold ) are two different things.

The assumption is that seating force is related to how hard the neck grips the bullet. Lube may affect the readings, but they are all done the same way.

 

[Chiquita]

What do you mean by primer crush?

Sorry, I meant anvil crush.

 

[JFrank]

The assumption is that seating force is related to how hard the neck grips the bullet.

I don’t like assuming, I prefer testing results and mine contradict that assumption.

 

[Chiquita]

Do you tumble after you anneal? I flame anneal and have noticed I get some “sticky seating” on cases if I do the tumble after annealing. I am dry tumbling with corncob.

I haven't tumbled for at least one or two years.

 

[6.5 forever]

AMP says that better SD is achieved by inside neck neck brushing after annealing. I don't know if this affects any of the other measure able steps. But I can feel a difference in smoother bullet seating.

 

[coldboreshot]

And the $100,000 question...
Is the target reflecting this issue or just the sensation your getting in the reloading process. You have not mentioned the effect on target.
Over the years, I have read many of the types of threads that have gone way off into weeds uneccessarily.

 

[Steve Donlon]

I just dump the neck into the neo lube/mica or there ie better method that is less messy?

what about the crush?

I take the depth of teh primer pocket minus the height of the primer. The result is deducted from the primer seating depth.

Like gmr4 said, a bottle cap or other small container and a Q-tip work great. I use the same oil I use to neck turn brass and on the mandrel. One Q-tip loaded with a small amount of oil will do a few cases at the same time. You don't need very much. I'm sure that The NEO LUBE works better though. I tried the mica stuff once and it did not work at all for me.

 

[6.5 forever]

I must be getting old. I could not figure out what the structure was beside the Neo lube bottle in the Amazon ad.....lol. I thought it was some kind of bottle holder or shaker.....it's time for a nap.

 

[Webster]

I don’t like assuming, I prefer testing results and mine contradict that assumption.

I assume that if the neck I.D. is .248 for a 6mm bullet there is zero force to seat a bullet.

 

[JFrank]

I assume that if the neck I.D. is .248 for a 6mm bullet there is zero force to seat a bullet.

That would be a good assumption but to my point, assuming that X amount of seating force (friction) on a gauge equals X amount of neck tension or consistent seating depth isn’t a good assumption.
The odds are that while using good tools the seating depth will be close but unless one varifies one doesn’t really know.

Seating force hasn’t changed a target for myself, bullet hold certainly has and seating depth variations have absolutely changed targets.

I trust this makes sense and clears up any previous misunderstanding .
Jim

 

[wkdickinson]

IMHO the biggest variable when measuring the force required to seat a bullet, is friction. The inconsistency of the surface inside of the case necks (to rough, too smooth, too much carbon, not enough carbon, too clean, not clean enough) and neck lube. That assumes reasonably consistent annealing and using a mandrel for final sizing.

 

[Webster]

That would be a good assumption but to my point, assuming that X amount of seating force (friction) on a gauge equals X amount of neck tension or consistent seating depth isn’t a good assumption.
The odds are that while using good tools the seating depth will be close but unless one varifies one doesn’t really know.

Seating force hasn’t changed a target for myself, bullet hold certainly has and seating depth variations have absolutely changed targets.

I trust this makes sense and clears up any previous misunderstanding .
Jim

I don't have the time, money, patience or a good enough rifle to test any of this. I just do what record setting guys like Erik Cortina do. Eric does a lot of testing. He has won many tournaments.

 

[LRPV]

Brushing, not brushing, lots of brushing vs a little brushing etc has more effect on seating force with a pressure gauge than anything else I’ve done. Now, that’s with the caveat of consistent sizing and annealing. I haven’t completed the rabbit hole journey with boujee lubes but early attempts still depended on the condition of the interior of the neck. I’m not much into the expander mandrels, correct bushing size has given me the same results so far. I turn my necks for most BR stuff but haven’t noticed “no turn” cases presenting many problems and know plenty of guys do just fine on target without turning.

Take your gauged outliers, which you’ve never said how big of a spread you’re seeing, and put them on paper. See if it even correlates. You may be surprised.