Inconsistent Neck Tension

[sunnyfisher]

I don't know that its effecting accuracy but when I seat the bullet there is a definite difference from case to case in neck tension.
I anneal after every firing with an Annie which I am very happy with by the way.
The cases are made by alpha and the same lot.
I use 750 Templaque on the outside of the neck and down just below the shoulder, with an induction annealer it shouldn't be necessary to paint the inside of the neck.
Then size and use graphite as a lube and a carbide expander mandrel before seating the bullet.
Do I have a problem or am I just paranoid?

 

[mike06]

I don't know that its effecting accuracy but when I seat the bullet there is a definite difference from case to case in neck tension.
I anneal after every firing with an Annie which I am very happy with by the way.
The cases are made by alpha and the same lot.
I use 750 Templaque on the outside of the neck and down just below the shoulder, with an induction annealer it shouldn't be necessary to paint the inside of the neck.
Then size and use graphite as a lube and a carbide expander mandrel before seating the bullet.
Do I have a problem or am I just paranoid?

Have you checked the case neck thickness? I have seen some brass have as much as a .002 difference measuring in four different spots around the neck.

 

[Zero333]

Are you sizing the brass before or after annealing ???

If you size the brass before annealing, then that's most likely your problem.

How do you clean the cases ??? wet tumbling makes inside the necks grabby and motor mica or graphite is a must as your doing.

 

[sunnyfisher]

I have not checked case neck thickness but I will.
I wet tumble with ss pins then anneal, then size and lube inside of neck with graphite.

 

[Ned Ludd]

One possible explanation is that the variance in neck wall thickness of un-turned case necks can be pushed to the inside when using a bushing die, because the die is squeezing everything inward from the outside. Some have had success addressing this issue by starting the re-sizing process using a bushing that is perhaps .001" to .002" smaller than would be selected if the bushing die was the only sizing step. That is then followed by opening the necks back up with an expander mandrel as the last step to achieve the desired neck tension. This has the effect of pushing non-uniform neck wall thickness to the outside. Because brass spring-back works in the opposite direction of a bushing when the necks are opened up from the inside with a mandrel, you would need a mandrel that is about .0015" under bullet diameter to achieve a neck tension (interference fit) of approximately .002". Likewise, mandrels that are .002" and .0025" under bullet diameter will give neck tensions of approximately .0025", and .003", respectively.

I use the following mandrels, which are available in .0005" increments, and die body for this purpose and they work very well:

http://www.xxicsi.com/caliber-specific-expander-mandrels.html

https://www.sinclairintl.com/reload...ls/generation-ii-expander-dies-prod38807.aspx

Another possibility worth checking is to ensure that the case mouth chamfer is sufficient and uniform. Certainly turning case necks is a well-proven method to achieve more uniform neck tension, even if it's just a skim pass to knock down the high spots, but it requires a bit more effort than a mandrel-based approach. Whether it's worth the effort largely depends on the intended shooting application and is a personal choice to be made by the end user.

 

[bozo699]

Carbon is your friend when seating bullets and I don’t feel any lube or graphite can replace it! I seldom ever clean my brass other than with steel wool then anneal. I lightly brush inside necks with a nylon brush and they seat like butter. Every time I’ve used steel pins our ultrasonic cleaners they seat as your finding yours are.
Wayne

 

[BenPerfected]

Annealing will help significantly with consistent neck tension.

 

[carlsbad]

You have now reached the 7th level of accurate shooting. This is one of the most difficult levels to complete successfully. Once you do, you'll be a much better shooter.

PS. I'm way ahead of you but haven't completed successfully. I know people who have. They have an SD well under 5 and an ES under 10.

 

[Jay Christopherson]

Dump the wet tumbling and the graphite. Either stop cleaning your cases, or just surface clean them (dry media tumbling) if you need them shiny.

EDIT: Or wet tumble no more than 15 - 20 minutes, MAX. You don't want to lose the carbon buildup in the necks.

 

[Uncle Ed]

Powdered graphite is nothing more than finely ground carbon and in Imperial dry neck lube. And if you wet tumble dipping your case necks in graphite will reapply a coat of carbon inside the case neck.

I would be more concerned about the posters problem of varying seating force and peened case mouths from wet tumbling.

Question, do you use a VLD deburring tool inside your case necks to remove the rolled over edge on the case mouth before seating your bullets?

Below is a once fired .44 Special case that had been trimmed and deburred, reloaded, and wet tumbled after firing. If these cases were not deburred again after wet tumbling there would be small fine brass flakes inside the case when expanded. And the expander would also be coated with small fine brass flakes.

If this happens using an expander what do you think happens when you seat a bullet and bullet drag?

This was the main reason why I started using a sonic cleaner that did not peen the case mouths.

 

[carlsbad]

So far you have suggestions for at least 6 things that I've tried and moved on from...

 

[power55316]

Don't wet tumble leave the carbon in the case necks

 

[mike a]

One possible explanation is that the variance in neck wall thickness of un-turned case necks can be pushed to the inside when using a bushing die, because the die is squeezing everything inward from the outside. Some have had success addressing this issue by starting the re-sizing process using a bushing that is perhaps .001" to .002" smaller than would be selected if the bushing die was the only sizing step. That is then followed by opening the necks back up with an expander mandrel as the last step to achieve the desired neck tension. This has the effect of pushing non-uniform neck wall thickness to the outside. Because brass spring-back works in the opposite direction of a bushing when the necks are opened up from the inside with a mandrel, you would need a mandrel that is about .0015" under bullet diameter to achieve a neck tension (interference fit) of approximately .002". Likewise, mandrels that are .002" and .0025" under bullet diameter will give neck tensions of approximately .0025", and .003", respectively.

I use the following mandrels, which are available in .0005" increments, and die body for this purpose and they work very well:

http://www.xxicsi.com/caliber-specific-expander-mandrels.html

https://www.sinclairintl.com/reload...ls/generation-ii-expander-dies-prod38807.aspx

Another possibility worth checking is to ensure that the case mouth chamfer is sufficient and uniform. Certainly turning case necks is a well-proven method to achieve more uniform neck tension, even if it's just a skim pass to knock down the high spots, but it requires a bit more effort than a mandrel-based approach. Whether it's worth the effort largely depends on the intended shooting application and is a personal choice to be made by the end user.

really like the .0005 increments. I have the k&m and .001 just doesn’t always get it. Mike

 

[dolek]

I clean however I feel like, I put carbon back in the necks before seating . I like being in control of the carbon .

 

[Alex Wheeler]

I would agree to stop wet tumbling. Try just polishing the indie of the neck with a tight fitting iosso nylon brush in a drill. No lube, no case cleaning, no mandrel. See how it shoots, you can bring back those other processes one at a time and see how the rifle responds. I have done a lot of testing with neck lubes and you can get good results. I just seem to get equally good results without it.

 

[Rick300]

I have had the same issue and found that stopping for a few seconds with the mandrel in the neck seems to make a difference. Along with the other suggestions above.

 

[fyrewall]

I turn necks and even with the best brass a certain unequal amount is removed from one side of the neck - just enough turning to allow a bullet to slip fit inside a fired case. I anneal every 3 firings, 15 seconds, just outside of the reducing part of the flame then size the brass. Removal of the baked on black stuff inside of the neck would involve lots of effort that might affect neck dimensions and increase cold welding. I use 3 in 1 lock lube (graphite) applied with a Q tip inside the neck before sizing for very minor expander drag but none for bullet seating. My neck mouths are clean and smooth. I like cheap Lee collet dies used with body dies - minimum work hardening and run out. No case cleaning other than to remove case lube with isopropyl alcohol and removal of black crust inside primer pockets. I think the signs of annealed brass look cool. Bullet seating after all that feels good & uniform.

I have had the same issue and found that stopping for a few seconds with the mandrel in the neck seems to make a difference. Along with the other suggestions above.

Brass spring back - dwell. Goes along with work hardening.

 

[sunnyfisher]

Powdered graphite is nothing more than finely ground carbon and in Imperial dry neck lube. And if you wet tumble dipping your case necks in graphite will reapply a coat of carbon inside the case neck.

I would be more concerned about the posters problem of varying seating force and peened case mouths from wet tumbling.

Question, do you use a VLD deburring tool inside your case necks to remove the rolled over edge on the case mouth before seating your bullets?

Below is a once fired .44 Special case that had been trimmed and deburred, reloaded, and wet tumbled after firing. If these cases were not deburred again after wet tumbling there would be small fine brass flakes inside the case when expanded. And the expander would also be coated with small fine brass flakes.

If this happens using an expander what do you think happens when you seat a bullet and bullet drag?

This was the main reason why I started using a sonic cleaner that did not peen the case mouths.

Uncle Ed Nailed it the culprit was burrs inside and outside of the casses
Well no more tumbling, have bought a ultrasonic cleaner, I have never had this problem before but there is always a first time.
Thanks for all the input.
I learned a lot.

 

[Scott Harris]

Sunny, what piece of advice did you hear over and over...from the very best shooters? ... hint ultrasonic cleaning is very similar to it.

 

[ngb1787]

Sunny, what piece of advice did you hear over and over...from the very best shooters? ... hint ultrasonic cleaning is very similar to it.

Scott,,what unit r u using?