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ANNEALING BPCR CASE NECKS
By Wayne McLerran
Updated 3/8/17

Annealing is essentially the opposite of hardening.  Steel is hardened by raising its
temperature to a range that allows the grain structure to be altered, which is then
“frozen” by quenching (rapid cooling).  If the steel is reheated to a high temperature
and allowed to slowly cool it will be annealed or softened.  Steel can be hardened or
softened by using heat but brass is different and can only be hardened by “work-
hardening” (stressing the grain structure) and only softened by applying heat.  
Reforming, resizing and simply shooting will work harden cartridge brass.  By the
way, if you hear or read that quenching hot brass will harden it, don’t believe it and
question anything else from the same source.

Prior to annealing BPCR cases, I had “hand annealed” high power smokeless
bottleneck case necks and shoulders.  The smokeless bottleneck cases were
annealed to eliminate neck and shoulder case-hardening resulting from full-length
resizing after repeated firings.  Annealing is also commonly utilized to soften case
necks and shoulders when reforming (converting) brass to use for a different
cartridge.  Since I use fire-formed straight-wall BPCR cases and finger seat (slip-fit)
bullets with very little or no neck tension I’d never considered that annealing the
necks was beneficial.  But during BPCR reloading discussions with a very
experienced shooter, he convinced me to try annealing.  He’d experienced some
problems with his reloads several years ago.  He was seating the bullets with neck
tension and did some testing indicating the problem was variations in neck hardness
which annealing will eliminate.  But at the time he didn’t believe annealing was
necessary with slip-fit bullets.  Later, additional testing confirmed that variations in
neck tensions, even with slip-fit bullets, directly resulted in measureable changes in
muzzle velocity and bullet impact vertical dispersion.  After annealing the variation
disappeared and accuracy improved.  Although finger-seated bullets are loaded
without significant neck tension, when fired and obturation occurs, annealing will
help mitigate the negative effects of inconsistent bullet release due to hard necks.

After annealing a large number of used cases for the 1st time, a neck expander was
used to check the neck ID of the fire-formed cases.  The slight resistance felt with
the expander was very uniform and consistent from case to case.  Prior to annealing,
even after using the neck expander, the resistance varied from case to case, which
was also felt when finger seating bullets.  Many BPCR shooters reload with some
neck tension and annealing is recommended on a regular basis.  Some experienced
shooters anneal after each firing as a normal part of their reloading process.  
Annealing is also recommended when initially using Starline brass, which has the
reputation of being harder than Remington or Winchester brass.  Another sign that
annealing is needed is when cases come out of the chamber with dirty necks
indicating the brass did not expand sufficiently or fast enough to seal out gas and
fouling blow-by or blow-back.  Finally, if accuracy falls off for no apparent reason
after firing the cases a few times than annealing may be in order.

Various techniques have been used to anneal brass while protecting the case head,
including but certainly not limited to the following.  Dipping the necks in oil then for
a few seconds in 800°F melted lead.  Standing the cases up in a pan of water with
the necks above the water, then heating with a torch until the necks turn blue and
tipping the case over in the water to cool.  Holding and turning the case with pliers or
an electric drill with the neck in the flame of a torch then dropping the case in a pan
of water.  Anneal until the necks glow red will result in damaged brass because the
temperature is well above the annealing range and the brass becomes too soft.  
Annealing in a dark room until the neck shows the 1st hint of glowing orange is a
much better approach and should work fine, but can result in overheating the brass if
you’re not careful and paying close attention.  The cases should be rotated and the
necks heated with a propane torch.  Use a drill and hold the case in a standard
socket slightly larger than the case.  Stop heating when the case neck shows the 1st
hint of glowing orange.  You can dump them on a wet towel or in water to speed up
the cooling process but it's not necessary.  Quickly cooling brass will not harden it
as it does other metals.

Cartridge brass can be annealed at temperatures as low as 480° to 490°F but will
require an extended time (hours) to fully anneal.  Even at 600° it may take an hour
or more and the complete case would be annealed, not just the neck, resulting in a
very unsafe condition.  If the head is annealed even slightly, it can fail and blow
apart when fired.  The solution is to quickly raise the temperature in only the neck
area to a range of 700° to 800°F, at which point the neck is fully annealed.  Since the
high temperature is only applied for a very short duration, typically 3 to 4 seconds,
the case heads will not exceed 480° unless the cases are shorter than about 1.5” to
1.75”.  By the way, YouTube has several videos on annealing.  But be aware, some
are clearly misleading and can result in damaging the brass due to overheating.

Hot Sand Case Neck Annealing
What you will need:
1)        Some clean playground sand.
2)        A stove and pot to heat the sand.  One of the Lee Precision electric casting
pots is an ideal solution.
3)        Casting thermometer to check the sand temperature.
4)        Some type of small simple metal stand to place in the pot and cover with
sand to the depth of the case necks.  One solution is to bend a piece of sheet metal
to fit.
You’ll need to experiment to find the preferred temperature, which will likely be
around 800°F.  Once the sand is heated to the desired temperature, stick a case neck
down into the sand until it hits the metal stand.  Stick another case in the sand and
remove the 1st one.  Increase the heat if the necks are not getting sufficiently hot as
indicated by a subtle color change.  Do not leave the cases in very long or the entire
case will become annealed and soft, resulting in an unsafe condition when the
resulting cartridge is fired.

Hand annealing using a propane torch
The hand annealing process I used consisted of heating the neck of a slowly rotating
case with a propane torch in a brightly lit room.  The cases were inserted into and
rotated with a standard ½” drive 5/8” socket using an electric hand drill.  Here’s a
similar process: https://www.youtube.com/watch?v=kgD5D0Wzu-c.  To ensure the
necks reached the correct temperature and were not overheated, Tempilaq, a
temperature indicating fluid was used.  750° Tempilaq was applied inside the case
necks of a few cases to determine the amount of time to hold the rotating case necks
in the torch flame.  Once applied it quickly dries.  When the Tempilaq temperature
is reached it liquefies and typically changes color.  When 750° Tempilaq liquefies it
changes from a light or medium blue to a dark grayish blue.  If it gets very dark or
black than you’ve overheated the brass.  Once the correct heating duration was
determined, Tempilaq was not used with the rest of the cases.  By the way, applying
750° Tempilaq to the inside of the case necks was found to be more accurate than
applying 650° Tempilaq to the outside of the case just below the necks.  After
annealing, the case was dumped out of the socket onto a soft towel.  Quenching the
hot case in water does not affect the annealing process and will not harden the brass.
Notes:
- 750° Tempilaq is very thin and wiping several layers or dabbing it on will normally
be required to build up an adequate light blue layer.  Fortunately it dries quickly.  
After heating the grayish dark residue should dissolve with water if it was not
overheated and baked on.
- Per the factory, when using any temperature range of Tempilaq, the key is when it
liquefies; not the color change although it should happen simultaneously.

I use Remington cases which are normally annealed shortly after being cleaned in a
tumbler with ceramic media.  Prior to annealing they are “sparkling” clean inside and
out.  What I found interesting is when the correct temperature was reached the color
change in the necks was very subtle.  They did not turn a deep blue or display the
vivid colors seen in some photos of annealed brass and in a few of the YouTube
videos.  It is my opinion that the vivid colors are a result of over-heating the necks
or possibly due to oxidizing of the case surface from aging.  The following photo
displays the before and after annealing results of brand new Remington, Winchester
and Starline brass and is similar to the color change of freshly cleaned brass.  The
brass was annealed using a carrousel-style semiautomatic annealer.  Although listed
as .45-90, the head of the Starline case to the right is actually stamped 45-2.6





































Damage from over annealing
So what happens if the brass is over-annealed (over-heated)?  Damage can result
because the brass becomes too soft and hardness can only be restored by work-
hardening.  Bottleneck case shoulders can collapse when seating bullets with neck
tension and the cases can be harder to extract for the same reason mentioned below
for straight wall cases.  As long as the base is not annealed, over-annealing the neck
is not a dangerous condition but can lead to case extraction problems, case stretching
and eventually separation.  If the case neck and/or body are too soft the brass will
not spring back as much after firing, possibly resulting in “sticky” extraction.  The
soft brass also has an increased tendency to stretch and will require trimming.  
Repeated stretching and trimming can eventually lead to case separation.  Too soft
case necks are also reported to result in less accurate loads, the opposite of what
proper annealing is meant to fix.

Although I shoot slip-fitted bullets, based on the uniform neck tension results after
annealing, which was very consistent from case to case, I plan on continuing to
anneal after each firing and will be using a carrousel-style annealer.  By the way, if
you plan to anneal short cases less than 1.75”, I highly recommend applying 475°
Tempilaq to the base area to ensure the base does not become annealed and quickly
dump the cases in cold water to stop the heat from reaching the head.  475°
Tempilaq is cream colored and turns clear when it melts at the indicating
temperature.

Concerning annealing equipment, prior to recent developments using induction
heating one could spend as little as a few dollars to hand anneal or over $800 for a
top-of-the-line carrousel-style propane-based annealer.  Induction heating is the
newest technology being applied to annealing cartridge cases.  It’s fast & precise
but, with prices up to around $1,100.00, the technology is not cheap.  Listed below
are three induction units dedicated to case annealing.  The expensive units, either
propane or induction based, do not guarantee a better result but do provide a level of
control and faster processing rate not available with hand annealing solutions.  
Following is a list of case annealing equipment suppliers.


Annealing Equipment Suppliers:

Hand Propane Annealing Kits:
By my way of thinking these are a solution to a nonexistent problem since a drill &
socket, which you likely already have, and a bottle of Tempilaq works just as well if
not better.
Note: A propane torch is not included with the following.

Meacham Tool & Hardware, Inc. Similar to the Hornady solution below, Meacham
sells “A Deal to Anneal” case holder that mounts in a drill to spin and dump the
case after the neck is properly heated.
















Enterprise Services, LLC
Anneal-Rite II Cartridge Case Annealing Unit.  Comes with three stands and one
case holder.


















The Woodchuck Den
The Woodchuck Den has been selling the Series II Annealing Tool, also known as
“The Ring of Fire” for several years to bench rest and varmint shooters to increase
the accuracy potential of their ammo.  It’s a neat tool that attaches to a Bernzomatic
torch for uniform neck annealing without the need to rotate the case.  You can either
hold the cases individually with pliers or stand them up in a flat pan with the bases
covered with water.














Carrousel-style Propane Torch-based Annealers:
These are certainly expensive but provide a level of control and faster processing
rate not available with hand annealing solutions.  
Note: Propane torches are not included.

Ballistic Edge Manufacturing
MODEL 360 - Constructed of zinc-plated welded-steel & features a one-size fits-all
rotating case drive wheel.  
The cases do not spin as they are being rotated.  Very
similar to the Brass-O-Matic, which is no longer manufactured.  Here’s a video of
the machine in action:
https://www.youtube.com/watch?v=8VyORewvKHY.
MODEL 400 – Precision machined from aluminum & features a rotating shell-plate
custom made for your choice of up to 4 sets of hole sizes.  
The cases spin as they
are being rotated
.















Ken Light Manufacturing
BC 1000 Automatic Case Annealer comes complete with one cartridge head wheel.
Additional wheels are available for a fee.  
The cases spin as they are being rotated.  
The designer and owner is Ken Light.

















Giraud Case Annealer (Giraud Tool Company, Inc)
Designed for volume annealing, using a propane torch assembly, the automatic case
feeder can handle several hundred .17 cal. to .50 cal. cases at a time by only
changing the feeder wheel disc and transfer plate, a 2-minute task.  See the unit in
action at
https://www.youtube.com/watch?v=tCWni2nNNeE.























Sagebrush Annealer,
A relative new product, the Sagebrush Annealer is a simple design and does appear
to do the job. The one disadvantage, and I consider it a major shortcoming, is the
inability to control speed. So the only heating control is the torch flame settings
which could be a drawback when setting it up for different cartridges.



















Bench-Source (Vertex Manufacturing)
The model 10G107 shell plate fits up to the largest magnum cases & can be
supplied for .50 BMG caliber.  
Using a different technique than the other brands, the
shell plate stops and the case spins while being heated.
 Although the unit is setup to
use two torches, only one is generally necessary due to the unique design.  The
designer and owner is David Dorris.
Note: Buffalo Arms (
www.buffaloarms.com) and Graf & Sons now sells the Bench-
Source unit

After considering the other brands, this is the unit I purchased and highly
recommend.  The design is well thought-out and the construction is excellent.  It has
all the features required plus some; comes with an excellent user’s manual and is
comparatively priced.  By the way, the carrier plates shipped with the current units
have an additional set of smaller holes in line with the larger holes which are not
displayed in the photo below.  They are for smaller cases such as .223, .222,
Fireballs, Hornets, Bees etc.  And for those of you that are curious as I was, the very
small holes closer in to the center in the photo below are used for manufacturing, not
for very small cases.





















Zephyr Dynamics, The Brass-O-Matic is no longer manufactured.  Refer to
the Ballistic Edge Manufacturing Model 360 for a very similar unit.


Here’re some examples of prototype propane torch-based automatic annealers:
https://www.youtube.com/watch?v=Jv75-9p9yFA
https://www.youtube.com/watch?v=9TMe5qcYILM


Induction Annealers
Utilizing the same technology used in electromagnetic induction heating kitchen
cooktops, induction brass cartridge case annealers are a relatively recent
development.   Currently they are more expensive than propane torch-based
annealers, but offer some benefits.  By controlling the power and timing, very
precise and repeatable temperatures can be applied to each case neck, eliminating
the risk of overheating the case.

Annealing Made Perfect (AMP) Induction Annealer
The unit was announced at the 2015 SHOT Show.  Currently at a retail price of
$1,099.99 plus shipping from Graf & Sons, the USA distributor & reloading
equipment supplier.  Each case is hand inserted using the correct pilot and standard
shell holder.





















Annie Induction Annealer (Fluxeon)
With over 1000 watts of induction heating power, a typical case can be annealed in
around 3 seconds.  Cases are inserted by hand.  The unit is currently priced at
$484.00 + shipping.

















Giraud Induction Annealer (Giraud Tool Company, Inc)
Combining the Annie Induction Annealer with Giraud’s case feeder assembly, results
in the only automatic induction unit on the market that I’m aware of at this time.  The
automatic case feeder can handle several hundred .17 cal. to .50 cal. cases at a time
by only changing the feeder wheel disc and transfer plate, a 2-minute task.  See the
unit in action at
https://www.youtube.com/watch?v=zL4eNCgm-C8.
Based on the price of Giraud’s automatic case feeder ($470) and Fluxeon’s Annie
Induction Annealer ($484), the total price is $954.00 + shipping.























EZ-Anneal
EZ-Anneal is the new kid on the block with a very nice induction annealer system
that was launched in Jan. 2017.  The new annealer is clearly targeted for precision
smokeless shooters, but a company representative indicated the EZ-Anneal XL
model will handle black powder cases without any problems.  The retail price is
$1,099.00 plus shipping.


















Here’re some examples of prototype induction annealing setups:
https://www.youtube.com/watch?v=Ny0a72_AX0E
https://www.youtube.com/watch?v=EGfGV8xrfak



Wishing you great shooting,
Wayne