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EVALUAION OF LOCKING HANDLES FOR
CASTING MOULDS
By Wayne McLerran
Updated 10/1818

First, a little background - I’ve been casting bullets for smokeless and more
recently black powder cartridges for nearly 35 years.  I’ve used Lyman, RCBS
and SAECO moulds with the appropriate matching handles.  The majority of my
current moulds are from Paul Jones (now retired) and Buffalo Arms (BACO).  
The moulds are based on SAECO blocks, therefore SAECO handles fit them
perfectly.  When casting .40 caliber 410gr bullets from a single-cavity BACO
mould the typical weight spread is +/- 0.5grs, which is certainly adequate.  But
during the last few years, after reading many online discussions, locking handles
caught my interest.  It has been my opinion that if a high-quality mould is used
with good handles and with a refined casting technique, locking handles are not an
advantage.  But I wondered if the weight spread could be further reduced, and are
there additional less obvious advantages to using the handles?

The functioning of locking handles is very similar to pliers commonly referred to
as vice lock pliers, lock grip pliers, or pliers manufactured under the well-known
"Vise-Grip" trade name.  The design incorporates an “over-center action”
adjustable link between the two handles.  In use the link is adjusted so that the
control handle lightly snaps over-center (locks in position) once the mould halves
completely close.  Adjusting the link determines how tightly the mould halves are
squeezed together.  Once set the pressure holding the mould together is consistent
from bullet-to-bullet, theoretically eliminating one of the variables contributing to
variations in bullet weight.  Prior to writing this article, the only two locking
handles I was aware of were made by Cabin Tree and R & J (Ron Jordan).

After a little online research it turns out the original Cabin Tree handles, slightl
y modified, are now manufactured by ST Machining and sold through Desperad
o Cowboy Bullets website. (
http://cowboybullets.com/Mould-Handle_p_5
6.html
) and Buffalo Arms Co (https://www.buffaloarms.com).  Two versions
(regular for 1 or 2-cavity moulds and long for 6-cavity moulds) are now available
in steel or aluminum.  The original Cabin Tree handles were only available in
steel.  The price is $70 plus shipping for all versions.  For this article I will refer
to them as STM handles and only the regular aluminum version will be
evaluated.  The R & J handles are available directly from R & J Mould Handles
(
http://www.rj-mouldhandles.com/), a Canadian based company, or from Shiloh
Sharps (
https://shilohrifle.com/reloading-supplies/r-and-j-custom-mould-
handles/).  The price is $75 plus shipping.  I decided to purchase one of each
brand and try them out.
When opening the box containing the R & J handles the 1st thing noticed was
the significant weight, which measured 1lb 11oz on a precision postage scale.  
As a comparison, standard SAECO handles weigh right at 1lb.  The 2nd was the
lack of instructions.  Being mechanically inclined I quickly figured out how to
adjust the handles but that may not be the case for some.  The 3rd thing was the
shape of the metal control handle.  It’s bent away from the main wooden handle.
Being right handed, when casting and using standard (non-locking) handles, the
handles with mould are held in my left hand.  After filling the mould I grab the
mould mallet with my right hand.  To open the mould the portion of the handle
that’s being held by my fingers is “flicked” open.  This is all done with one hand
and is impossible with the R & J handles due to the control handle design.  I
should make it clear at this point that having to use two hands to open the mould
is not a significant disadvantage, but after casting 25 bullets I quickly lost
interest in using the handles due to the weight and resulting hand fatigue, which
is contrary to the advertised benefits listed on R & J’s website.   And I don’t
have what I consider weak wrists or hands.  As a comparison, with standard
SAECO handles, I can easily cast a session of 120 bullets or more without
fatigue.  

By the way, I do know that some shooters use two mould/handle setups to speed
up the process when casting larger/heavier bullets – setting one aside to cool
slightly while filling the other.  As noted earlier, the heaviest bullets I cast are
around 410grs.  After the mould is preheated and the alloy is ready, my casting
rate is approximately 120 bullets per hour.  Therefore using two setups would
not be an advantage for me.

Upon opening the box containing the STM aluminum handles the lighter weight
was quite obvious.  To be accurate the handles are not constructed of all
aluminum.  The control handle and a portion of the adjustable link are steel.  
The handles weigh 11oz, a full pound lighter than the R and J handles and 5oz
lighter than the standard SAECO handles.  Even the all steel STM handles only
weigh 1lb 1oz.  Oh, and excellent instructions were included.

One possible negative of aluminum handles is it takes longer to bring the mould
up to casting temperature since aluminum is a much better conductor of heat
than steel.  I use a small laboratory hot plate to preheat my moulds.  When
casting with a BACO mould and steel SAECO handles the hot plate easily
preheats the mould to the 440 to 450 degrees, my desired starting mould
temperature.  With the STM handles and BACO mould the temperature peaked
out at approximately 400 degrees and it took a lot longer getting there.  I tried
out the handles by casting 135 408gr bullets without stopping.  Afterwards the
bullets were weighed in the order cast.  I was not surprised that 13 of the 1st
bullets had to be discarded due to significantly lighter weight.  I also found a
faster cadence was required while casting to maintain the mould temperature,
which should be a distinct advantage when casting larger 45 caliber bullets.  By
the way, due to the light weight and locking feature I could have easily extended
the casting session to 180 bullets or so, which is sufficient for three silhouette
matches, but would have required adding additional alloy to the pot.

With the STM handles I was able to use my left hand to flick open the mould
since the control handle was much closer to the main wooden handle.  The one
feature I felt was missing was a sprue plate stop, which I added after the 1st
casting session and was a needed improvement to prevent the plate from rotating
too far when opening and getting in the way when closing the mould.  Since the
ideal location of a sprue plate stop is dependent on the design of the mould (1 or
2-cavity) and shape of the sprue plate, I can understand why it’s not a standard
feature.  I drilled, tapped and installed a 10-24 threaded bolt of the appropriate
height, which was easy enough.  Another option is to drill a hole and install a
bolt with two nuts to lock it in place.

By now you’re probably wondering if I answered my main reasons for
evaluating the handles.  It should be obvious which one of the two brands I
recommend.  Clearly the STM aluminum handles are my preferred choice.  
Based on my testing, I doubt there’s an advantage to using the STM all-steel
handles but I did not evaluate them.  There’s no question the R & J handles are
of sturdier construction than the STM handles, but along with the heavier
construction comes significant more weight.  The final question to answer is
will locking mould handles reduce the weight spread of the bullets?

In the opening paragraph I mentioned my typical casting session results in a
bullet weight spread of +/- 0.5grs.  On bad days it can be worse, on a good day
a tad better.  The following photo will give you a visual indication of the spread
of 122 bullets that were cast with the STM handles after tossing the “cold
mould” rejects.  The mean (average) weight is 408.7grs.  The lightest is 408.2
grs and the heaviest is 409.2grs, resulting in a spread of +/- 0.5grs.  By the way,
since the sorting board I made was not tall enough, four of the bullets “spilled”
over the top of the board.  Although the spread was the same as my normal
results, you’ll have to take my word for it that using the handles did decrease the
standard deviation (SD) of the bullet weights.  The overall shape of the weight
distribution envelope is taller and narrower since a higher percentage of bullets
weigh at or very close to the mean weight.  For those of you “into” statistics the
SD was 2.09, the variance 0.44grs and the mean was 408.69grs.  For any
statistical experts reading this please cut me some slack since I may be loosely
using some statistical terms.
Finally, wondering how well the aluminum STM handles stand up to wear at
the pivot joints, I discussed them with Ed Kemmerer, the owner of ST
Machining and Desperado Cowboy Bullets.  He indicated there have been no
issues or complaints.  And before I forget one final benefit, for those of you
with arthritis in your hands, locking mould handles should be a definite
advantage since, once the handles are locked, hand pressure can be reduced
while filling the mould and waiting for the sprue to solidify.


Wishing you great shooting,
Wayne