Neck sizing

[diverwcw]

I have reloaded for many years and have always done full length resizing. Recently, I decided to try neck sizing and bought the Lee collet dies. After neck sizing the brass, the casings cycled through my bolt action rifle flawlessly (just the deprimed neck sized casing, nothing loaded). After I seat the bullet, it is held in place by neck tension but it I can still move the bullet further into the case by hand, although it takes some pressure.

The instructions are pretty clear, they say when resizing the casing, you will feel the spent primer being extracted. Then it says it takes about 25 pounds of force to properly resize the case. I darn near break my bench trying this but I can't feel any movement in the die.


Am I doing something wrong or is this natural?

I have submitted the same question to Lee Precision and am awaiting their response.


Thanks in advance.

[Dave626]

The lee neck size is completely different design. It actually squeeze the case neck into the die mandrel. I think you are fine. The lee neck die neck tension is about 0.001 if your case neck really thin. I use it for my single load precision rifle only.

[J-cat]

No he is not fine if he can move the bullet in the neck by hand.

[foesgth]

I had the same problem. I ended up using a Lee factory crimp die. It gave more consistant velocities.

[JagerDog]

You can polish down the mandrel or Lee will provide an undersized mandrel.

Been awhile, but I don't recall a handle force spec. That would depend on the mechanical advantage of your press.

[J-cat]

Do you have the die adjusted so that you feel the neck being compressed against the decapping rod? If not, turn the die in some more.

[jimmykan]

If you are sizing the inner diameter of the neck to at least 0.001" under the bullet diameter, there should be enough neck tension to keep the bullet from moving by finger pressure.

[Whiterabbit]

No he is not fine if he can move the bullet in the neck by hand.

You can polish down the mandrel or Lee will provide an undersized mandrel.

One and done.

Use 2000 grit wet paper and a drill and a micrometer if you have one, and a caliper if you don't.

[Ramsh00ter]

Maybe hard necks?

Just another thought, how many times have these cases been fired?

If they have reloaded several times without annealing the necks, they could be pretty hard. The neck is going to spring back after sizing.

I would think squeezing them down for a .001" tension would not be enough on hard brass.

I have never thought .001" under size on the neck was enough, even on my BR rigs I use pin gauges to make sure I have a inside diameter of .002" under caliber on a sized case. On a case that will go thru a magazine, I shoot for .004-.005 under. There there is not danger of setting a bullet deeper when cycled thru the mag.

Using the pin gauge also allows me to check for donuts. I keep a set of pins in .240" thru .246" in .0005" increments on my bench for 6mm. Tells you allot about what is going on with your necks.

JMHO

[bsumoba]

[fguffey]

The instructions are pretty clear, they say when resizing the casing, you will feel the spent primer being extracted. Then it says it takes about 25 pounds of force to properly resize the case. I darn near break my bench trying this but I can't feel any movement in the die.

You use tension, I use bullet hold therefore there is no need to ask you how much tension your neck has because there is no tool available to measure tension.

And then there is that other part; you started out neck sizing and then when to "properly resize the case". When I neck size I use just a hint of effort when sizing the neck, the neck sizing die is designed to size the neck down short of the shoulder of the case meaning that is as far as the ram can travel; you can turn the work bench over with the press handle without sizing the case with the 25 pounds of effort, your press is locked up.

I have used feeler gages to adjust the die off the shell holder to reduce the amount of neck sizing.

F. Guffey

[JagerDog]

You use tension, I use bullet hold therefore there is no need to ask you how much tension your neck has because there is no tool available to measure tension.

And then there is that other part; you started out neck sizing and then when to "properly resize the case". When I neck size I use just a hint of effort when sizing the neck, the neck sizing die is designed to size the neck down short of the shoulder of the case meaning that is as far as the ram can travel; you can turn the work bench over with the press handle without sizing the case with the 25 pounds of effort, your press is locked up.

I have used feeler gages to adjust the die off the shell holder to reduce the amount of neck sizing.

F. Guffey

Collet die is very different. It squeezes the OD over a mandrel (ID).

Tension (or compression) is measured in units of force. Pounds are one unit of force. Force is a resultant of the interference fit (and other factors). The interference is readily controlled. The force, while measurable, is not readily controlled (when the other factors are induced).

[jimmykan]

There is a way to measure bullet seating force, which should be proportional to the neck tension.

https://lewilson.com/k-m-precision-arbor-press-with-standard-force-measurement-ram-and-dial-indicator/

That said, there will be variation in the relationship between the bullet seating force and neck tension measured as the difference in bullet and inner neck diameters, if there is a variation in the levels of brass work hardening in the case neck. Between an annealed case neck and a thoroughly work-hardened case neck of the same inner diameter and wall thickness, the annealed neck will be softer and have less spring-back so it does not contribute as much neck tension that grips the bullet while the work-hardened case will be harder and have more spring back that contributes to the bullet gripping force.

It is best to anneal the necks on a batch of brass at the same time for the most consistent neck tension.

You will also notice a difference in neck spring back when neck sizing: annealed necks will size down and stay closer to the nominal mandrel or bushing diameter, while work hardened necks will spring-back more towards their pre-sizing diameter.

[ar15barrels]

^^^THIS!^^^

[LynnJr]

Galled lugs and broken handles? That guy must be a nutjob! Remember the thread on one piece bolts? Nobody here has ever heard of a galled bolt or broken handle!
Lolroflmao