MB October 2014 ss 2x.pmd - National Muzzle Loading Rifle

Triggers: Set or Simple? Part II
By Fred Stutzenberger
“The lightest trigger pull force consistent with safety is what you are trying to achieve. You
should never feel the trigger bar touch the sear because that promotes flinching. You should
not be able to feel any resistance when you squeeze the trigger because that disturbs the point
of aim. Good accurate shooting comes from concentrating on your sight picture not from
worrying when the rifle is going to fire.” (Alexander 171).
The variety of set triggers that are commercially available is amazing (Fig. 1). Some of the major muzzleloading
parts manufacturers offer more than ten different double
set models. There are set triggers marketed specifically for
Jägers, others specifically for Southern Mountain (Tennessee) rifles, some are spittin’ image duplicates of those on
old original Hawkens, some for Scheutzens or other late
period halfstocks and some that are specific to a particular
school of longrifles. This plethora of models can be divided
into three general types: the double set/double lever
(DSDL), the double set/single lever (DSSL) and the single
set (SS) trigger versions (Fig. 2). With DSDL or DSSL triggers, the rear trigger is pulled to ‘set’ the front trigger. When
set, the front trigger’s pull can be set very light and short.
My old Pop Spence DSSL trigger could be set so light that
flicking cigarette ashes on the front trigger would set it off
- definitely unsafe and stupid kid stuff!
Fig. 1. This is a small sampling of the commercially available set trigger
assemblies.
Part I of this series described methods for the construction of simple single trigger assemblies, the advantages of
attaching those assemblies to their trigger guards and mechanisms for their inletting. Part II will focus on improving set
trigger assemblies for reliability, safety, and appearance.
If you page through the premier books describing the American Longrifle (such as Kindig’s Thoughts on the Kentucky
Rifle in its Golden Age, Johnston’s Kentucky Rifles and Pistols 1750-1850, and Shumway’s Rifles of Colonial America),
you’ll notice that most of them have simple single triggers.
On the other hand, the majority of old original Jäger rifles featured in Shumway’s series “Our Germanic Rifle Heritage” in
Muzzle Blasts, 1991-93, had some form of set trigger mechanism. Today, a higher percentage of Jägers and longrifles are
equipped with set triggers. Why is that when the properly designed and installed simple trigger meets most functional requirements? One logical reason might be that in the old days,
it was labor-intensive to hand-make set triggers that required
metallurgical skill in the forging and tempering of springs and
the hardening of parts. Today well-made set triggers are widely
available to any builder no matter what the skill level. Perhaps
availability rather than necessity is the answer to why we see
more rifles equipped with set triggers.
October 2014
Fig. 2. Noted makers such as R.E. Davis, Dru Hedgecock, and L&R Lock
Company provide set triggers appropriate to Jägers and Hawkens and
everything in between. The DSDL triggers at top are a close copy of the
original Hawken triggers, able to fire set or unset. The DSSL trips the sear
only from the set position. Near the bottom are the single set type, most of
which must be set by pushing the trigger forward before the lock will hold
at full cock. The brass assembly (second from the bottom) is unusual in
that the forward trigger is the “set” while the back trips the sear. Potentially unsafe for anyone not familiar with this turnaround arrangement.
With the DSDL trigger, the rifle may be discharged via the
front trigger alone, but because of the relatively poor mechanical advantage (low pivot point far from the sear bar),
the pull is much harder (usually over 4 pounds) without using
the set mechanism (we’ll see a comparison in that regard later
on). Hunters I have talked to about using the DSDL front trigger only tell me that they always shoot in “set” mode rather
35
Fig. 3. This old original single set trigger is the rare exception to the usual
DSDL triggers usually found on original J & S Hawken rifles. It has an
unusual roller/cam arrangement employing a cam ring rather than a simple
projection on the toe of the trigger (Holm 5).
than using the front trigger as a simple single. It is sometimes asserted that the DSDL trigger system makes carrying
a cocked gun a little safer while still allowing the trigger to
be pulled in case a shot is needed quickly (of course, you
have that with a simple single trigger, so what’s the point?).
Basic firearms safety dictates a rifle should not be carried
around with the hammer at full cock unless a shot is imminent. Many foolish, absent-minded things happen in the heat
of the hunt (and sometimes in timed matches too); remember that the primary safety mechanism is the hunter himself,
not the action of the rifle. This maxim applies to modern arms
as well; safeties are not always safe.
For those who consider a DSDL trigger as a must-have for
any reason, let’s go through the basics. The assembly usually
consists of the following:
√ A plate on which all moving parts are mounted
√ front trigger (operates both set and unset)
√ rear trigger (operates only in set position unless pushed
forward manually)
√ front trigger tension/return spring
√ main spring (acts on rear trigger)
√ adjustment screw (alters engagement of the triggers)
√ mainspring screw (holds mainspring in place on plate)
√ pivot pins on which triggers rotate
One justification for installing a DSDL trigger is that the
style of your rifle demands it. Yet, even there, you have some
latitude; for example, almost all original Hawken plains rifles
were equipped with DSDL triggers. Yet some Hawkens had
36
SS triggers, built on special order per the preference of the
customer: the J & S Hawken rifle made for G. W. Atchison in
St. Louis in 1836 is a good example (Holm 3). The unusually
ornate Atchinson rifle had a roller/cam arrangement. The
position of the roller in relation to the cam was controlled
by an adjusting screw that acted on the underside of the trigger blade (Fig. 3). Some modern SS triggers are based on the
same cam-action principle (Fig. 4) in which the mainspring
travel can be controlled by a set screw.
Incidentally, while on the subject of SS triggers, R.E. Davis
(http://www.redaviscompany.com/locks.html) has recently
added one to their product line. The #0002RF trigger was
designed by Rick Frederick, a gun builder and blacksmith from
Findlay, Ohio. The 0002RF design was developed after a study
of many originals and functions both as a simple single pull
and as an SS trigger. The action is mounted on a .450" wide
plate and sets to a .500" overall height.
Another reason for a DSDL trigger (not nearly as good) is
that you just must have set triggers to compete with the other
guys at the local matches. That reason puts trigger selection
in the same category with parents at Christmas and must-have
toys for over-indulged offspring. At the matches I have attended over the last forty plus years, I haven’t noticed any
correlation between winning and trigger type or rifle appear-
Fig. 4. This modern single set trigger operates on the cam-over principle
and has adjustment for mainspring travel. Limiting the mainspring travel
will work on most SS triggers, at least those on the roller/cam principle. A
setscrew and shim were installed under the mainspring/roller assembly to
limit its travel. Note how much free play there is between the trigger cam
and the mainspring roller when the trigger is at rest.
Muzzle Blasts
Fig. 5. A coil spring between the head of the set trigger adjustment screw
and the plate keeps the screw from working itself out of adjustment to the
point where the triggers are unreliable in the set position. Note the mainspring travel set screw.
ance or barrel length or caliber or authenticity of regalia. Although some muzzleloaders can be as fanatic as golfers about
the equipment-performance relationship (and we all know how
goofy golfers can be), it’s the lady or gentleman who’s pulling the trigger or swinging the club that matters, not the type
of trigger or club itself.
If you care about improving your DSDL trigger assembly,
you should first address the safety issues. Look at the little
screw protruding through the plate between the triggers. That
is the trigger pull adjustment screw. As you screw it further
into the plate, it bears up under the blade of the front trigger,
making the trigger trip pressure less and less until it reaches
the point at which it will no longer set. Some commercial set
triggers leave the factory with adjustment screws loosely fitting the plate; you can turn them in and out by just running
your finger tip over the head. If you do not stabilize the position of the screw, it may work itself up or down in the plate
(not a good situation), possibly to the point where the trigger
will trip itself. If the adjustment screw is not stable, trigger
pull can be altered by inadvertently brushing the screw head
when you are setting the triggers, by the repeated recoil of
the rifle, and by long bumpy truck rides. A shooting buddy of
mine had that last possibility happen to his rifle during a long
drive over a gravel road to a remote rendezvous location. How
October 2014
the adjustment screw got out of his trigger plate and into his
rifle cover is a mystery – perhaps prolonged vibration worked
some mischief – or maybe the screw threads were just worn
too loose to stay put. No safety factor there, just a relatively
hard trigger pull would result, but remember that every time
you pull the front trigger, the recoil can do things to a worn
adjustment screw when the downward pressure of the forward trigger blade is off the tip of screw.
In any case, you definitely do not want the adjustment
screw to work itself further up into the plate. If the screw is
loose and your fingertip brushes the front curvature of the
screw head every time it passes between the triggers, you
could lighten the pull a tiny bit at a time. To prevent that, you
can install a little coil spring (one from a retractable ballpoint
pen will work) between the plate and the screw head (Fig. 5)
to put tension on the screw. If you can’t find a spring of the
correct size, a thick leather washer will do. Peening the
threads to distort them a bit is not wise. You could apply
Loctite thread locker once you arrive at the comfortable trigger pull if you can’t find a replacement screw (some are a
special thread or might be metric).
Many of the old original rifles had DSSL triggers
(Alexander 181). The DSSL triggers have only a single lever
and are designed to be set before they can trip the lock. If
your rifle is to be used primarily on the range, shooting competitively from the bench or offhand, a DSSL trigger will do
as nicely as a DSDL. There are those who condemn the DSSL
Fig. 6. This DSSL trigger has a mainspring travel adjustment screw threaded
through the plate and locked with a nut on the inner side. Note the relief
ground into the lever to allow cocking of the lock without setting the triggers. The front trigger tension spring was too weak, making it unsafe; it
was replaced with a sturdy coil spring for more secure trigger engagement.
Think safety first with every modification.
37
trigger as being unsafe because “the lock cannot be cocked
unless the trigger is set.” That condemnation is naïve; a mainspring travel adjustment screw can be installed by threading
through the plate to bear up under the belly of the mainspring
to limit its travel (Fig. 6). If the mainspring travel is properly
limited, it will pop the rear lever up to trip the sear, then let it
fall back down to allow the lock to cock again without trigger
setting. Installing a set screw to limit mainspring travel however, will allow the trigger lever to pop up, release the sear and
keep plenty of play under the sear bar to allow safe cocking of
the lock without interference from the trigger lever. Being able
to cock the rifle without having the triggers set to fire is safer
than cocking the lock over a trigger ready to trip the sear.
There are advantages and disadvantages in limiting the
DSSL mainspring travel. If the mainspring is allowed the full
travel of its design, it will overcome a multitude of sins in
the function of a less than perfect lock. It will overcome the
excess resistance created by an overly deep or improperly
angled full cock notch in the tumbler. It will function equally
well with or without a fly in the tumbler. Moreover, it will
take much of the pressure off of the fly; DSDL triggers knock
the sear out of the full cock notch then let the fly do all the
heavy lifting in getting the tumbler to the rest position without breaking the half-cock notch.
Another mainspring issue relates to the fit of the set trigger plate to the rifle. Because of its thickness in the middle,
the set trigger plate (unlike the simple trigger plate) offers
little latitude for reshaping. If you are tempted to reshape the
curvature by bending the back half of the plate, remember
that the heel of the mainspring bears against the plate; if you
bend the rear of the trigger plate up or down to conform to
the belly of the rifle, it will alter the main spring tension.
Bending the plate down from the heel even a tiny amount will
decrease the spring tension so much that the rear trigger will
not trip the sear (or does not do so reliably…which is worse
because you might not notice until damage to the lock is done).
Soldering a shim to the plate (Fig. 7) puts more pressure up
against the heel to restore proper mainspring tension. The
mainspring needs to give that back trigger blade a good kick
to clear the full cock notch and allow the nose of the sear to
easily pass over the tumbler fly.
Getting the proper clearance between the triggers and the
lock’s sear bar can be a bit of a problem. Some problems are
generated by the relative positions and heights of the trigger
levers and/or the angle of the trigger assembly to the lock. In
an ideal world, the front trigger in the unset position will trip
38
Fig. 7. After bending the trigger plate, the mainspring tension was restored
by soldering a shim under the heel of the spring.
the sear without excessive travel. In the set position, the front
trigger does not contact the sear bar before the back lever
does. On some DSDLs, the forward lever must rotate through
a large arc before releasing the back lever. This could result
in having essentially a simple single trigger in DSDL form
since the forward lever contacts and trips the sear before it
releases the back lever. You are left wondering why the trigger pull is so hard no matter how you try to adjust it. Essentially you’re operating your DSDL triggers in single trigger
mode and not getting the advantage of set triggers.
If you are building an ultra-slender rifle with one of those
faddish ¾" diameter pea-shooting barrels, there will not be
much room between the trigger levers and the sear bar. As just
described, you want the bar to be as close to the front trigger
lever as possible (to minimize trigger travel when firing using
the front trigger only) and yet have enough room for the rear
lever to flip up, hit the bar, and then drop back down out of the
way so that it does not interfere with the action of the sear. The
worse possible situation in that regard would be preventing the
sear from engaging fully into the half-cock notch. Very unsafe! With the lock firmly in place, coat the sear bar with
Fig. 8. The rear lever of this DSDL trigger was ground to conform to the
necessary curve in the sear bar shown in Fig. 9.
Muzzle Blasts
inletting black and then
gently slide the trigger
assembly into its mortise while gently holding the rear trigger
back , but in its unset
position. If there is
black transferred to the
rear trigger lever, it
will have to be ground
for clearance. On my
slender North Carolina
Fig. 9. This sear bar was bent upwards to
rifle, I ground the rear
get the proper clearance over the triggers.
trigger lever at an angle
(Fig. 8) to conform to the necessary curve in the sear bar (Fig.
9). Keith Lisle (at CustomMuzzleloaders.com) suggested a
better way by bending the back of the sear up rather than the
bar. I was afraid that bending the back of the sear too close to
the nose would ruin the temper, hence the bent arm. When
Keith bends the sear arm up, he re-tempers it by heating it
cherry red and dropping it in a cup of motor oil. He has no
technical data on this method, but it has worked for him on
more than 40 rifles
with never a broken
sear arm.
L&R Lock Company (see supplier list)
came up with a modification to provide
clearance of the sear
bar without bending.
Their RPL lock line
has a deep sear arm
that can be ground to
provide just the right
amount of distance
from the trigger levers
(Fig. 10). If you have
not used one of their
RPL locks designed to
10. This L&R RPL lock has a sear bar,
replace a variety of Fig.
a nice feature that can be ground for proper
earlier, lower quality clearance rather than heating and bending.
locks, you might not
be aware of this nice feature. It sure would have saved me
some bending and grinding. Perhaps other lock makers should
look at this feature.
October 2014
Fig. 11. This little fixture block speeds set trigger disassembly and reassembly.
Speaking of working on set triggers, I have always been
challenged when trying to line up the holes when putting pins
back through the plate and triggers – you can’t see the hole
through the trigger because it is covered by the plate. Having
a little fixture block (Fig. 11) that will do the alignment automatically is really handy. Mine was adapted from a scrap block
of steel that had several holes already drilled into it. I put the
assembly over a hole and then punch out the pin. If the block
is on a solid surface, the hole captures the pin. Lift the block
and pick up the pin. For reassembly, I added a little indexing
pin that is just long enough to go through one wall of the set
trigger plate and a little way into the trigger itself. Slip the
plate over the pin, move the trigger around until it lines up
and lets the plate drop to the surface of the fixture block,
then insert the pivot pin knowing the holes in the trigger and
plate are aligned. The #6-40 screw threaded into the block is
there available as a handle projecting from the mainspring
screw hole in the plate and can be turned down against the
mortise bottom to pry a tightly fitting plate back out when
you are inletting the triggers.
No matter what your style of longrifle, consider attaching the trigger plate to the guard using two small screws (#348) as described in Part I. Making set triggers and guard as a
single assembly will be as beneficial for set triggers as it is
for simple set triggers. Attaching the two parts will increase
their rigidity and aid in the removal of the trigger assembly
since the guard can be used as a handle (the Hawken Brothers
knew that and designed rifles to last through years in the wil-
39
Fig. 12. This soldered lap joint extended the trigger plate to allow attachment to the guard return.
Fig. 13. The wear polish on these modified triggers shows their many years
of use compared to an unused set.
Fig. 14. This front trigger needed an extension.
derness a thousand
miles away from the
closest gunsmith). If
the trigger plate is a
bit too short to reach
the rear trigger guard
return, solder on an
extension (Fig. 12). I
use a lap joint (at least
¼" overlap) joined
with Hi-Force 44 low
temperature silver solder (see suppliers).
Always use a lap joint
when possible because
it is so much stronger
than a butt joint.
Fig. 15. A shoe was fashioned to fit over the
Set triggers do not thinned trigger.
allow as much aesthetic latitude as do simple single triggers with their cute
curls and fanciful fronds. However, you can make clunkylooking commercial triggers look sleeker by a bit of reforming. Long ago, I bought several sets of Dixie DSSL triggers.
They worked OK, but just looked clunky (Fig. 13). So I reshaped a set and installed them on Woody, my favorite offhand rifle for over 30 years. For building my latest Jäger rifle,
I reshaped a set of L&R triggers (Fig. 14) by silver soldering
an extension (Fig. 15) to the short front trigger to make it
Fig. 16. With a little trimming, this lengthened trigger will custom fit
the guard.
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40
Muzzle Blasts
Fig. 17. Carefully drawn layout lines are traced with a center point to
ensure alignment with the stock.
Fig. 19. The angle of the tang bolt to the front slope of the set trigger
plate is pretty acute, whether in the original Hawken or in this Jäger
guard/plate assembly.
look closer (Fig. 16) to the old original Jägers with those
long spindly triggers. Now my blind forefinger doesn’t have
to hunt for that stubby front trigger – just slide down the front
of the bow and there it is.
Judging by the images so far, you will have gathered
that inletting set triggers is more complicated than for
single triggers. The plates extend so much further so you
have to set up your guidelines very carefully (Fig. 17). I
use a center point to trace over the guideline the whole
way to make sure that my milling table travel is aligned
with the stock. The trigger action part is milled first, followed by the plate and then the mainspring mortise. Milling generates a lot of chips flying around to obscure your
guidelines (Fig. 18), so having a VA (vacuum assistant) is
really handy. Lacking a VA, hook up your shop-vac on your
drill press to keep the mortise cleared of chips. Always
wear a dust mask because any fast-moving tool will throw
off a lot of dust, some of which will surely find its way
into your lungs.
Set triggers have contoured plates that will complicate
accurate placement of your tang bolt, no matter what the
rifle type because the bolt goes through the plate at so much
of an angle (Fig. 19). Maybe some people can eyeball it
accurately, but for mere mortals such as I, a drill alignment
tool is a necessity. Some of those were illustrated in Part I,
but I want to show you another neat and versatile tool made
by Dave Rase (Fig. 20). It has 2 pilots for clearance and tap
drill bits and a clamping feature to keep everything in place.
Specialty pilots can also be ordered.You can get one of these
by contacting Dave at [email protected]. I
hear that he does fantastic barrel inlets and ramrod holes
that stay where they should be.
After regaling the reader with the virtues and vicissitudes
of the set trigger, I hate to be a party pooper by injecting a dose
of numerical reality. Table 1 is a compendium of pull weights
of three rifles and four pistols with simple single triggers and
four rifles with DSDL set triggers. Ask yourself what would be
your ideal pull for what you are planning to use your rifle. Then
look at the table. Note first that simple single triggers have
pull weights less than the pull weights of set triggers in the
unset mode. No surprise there. Note also that the average of
standard deviations (SD) for the pull weights of the front triggers in the unset mode was nearly double that of the simple
single triggers. Of course the pull weights for simple trigger
and unset DSDL triggers both depend on the bearing surfaces
of the lock. Still, it is something to consider when agonizing
whether to go simple or set.
Fig. 18. Milling throws off a lot of chips, but saves a lot of time in getting a
clean trigger mortise.
October 2014
Fig. 20. This drill alignment tool by Dave Rase will save a lot of hand
wringing over a tang bolt hole gone astray. The homemade job at the
bottom was made by Keith Lisle.
41
Finally, I would like to include another informative observation by Keith Lisle:
“Most double set triggers are not designed to give an
easy front trigger pull. The pivot points are too low and
the trigger bars are too low. Now they can be modified to
make them work well, if a person wants to take the time
and effort to mess with them. Most of the rifles I build
with double set triggers will have a Davis DST4, DST6 or
a Davis Jäger trigger. On all of them I have to modify the
trigger bar to get a easy front trigger, yet maintain a crisp
light rear trigger.”
Keith went on to offer some hope to those who wish to
use the front trigger in the unset mode:
“I was in a conversation with some guys the other day about
DST triggers. One said all the front trigger is used for is to
trip the set trigger. Several others agreed. I didn’t. I told them
if you want to take the time and effort, you can make that
front trigger 3-4 pounds of pull pressure. But it will not happen in 15 minutes!”
I’m going to hold him to his promise to show me how he
does that modification.
Suppliers
Brownell’s (www.Brownells.com) 1-800-741-0015, for
silver solder and a wide range of gunsmith tools and supplies.
Dru Hedgecock, Inc., 5420 Morris Hill Ave., Walkertown,
NC 27051, 1-336-595-4257 for a wide range of triggers and
trigger guard castings
L&R Locks (www.lr-rpl.com) 1-803-481-5790 for 11
styles of muzzleloading triggers.
R.E. Davis (www.REDavisCompany.com) 1-419-8331200 for 17 styles of muzzleloading triggers
Acknowledgments
Thanks to Dock Houston and Scott Kaufman of Clemson
University Machining and Technical Services for their excellent mechanical assistance in my experimental
meanderings. Thanks also go to Keith Lisle for his insights
born of many experiences. Thanks go out to John Cummings,
Clemson University Department of Biological Sciences for
impeccable editing.
References
Alexander, P.A. The Gunsmith of Grenville County: Building the American Longrifle. Texarkana, TX: Scurlock Publishing 2002.
Buchele, W., G. Shumway and P.A. Alexander. Recreating
the American Longrifle. York, PA: Shumway Pub., 1980.
Holm, B. “A Newly Discovered J & S Hawken Rifle,”
Muzzle Blasts, Apr. 1981, p. 3-7.
MB
Table 1. Pull weights of simple single and DSDL triggers either set or unset.
Lock & Triggers
Transitional Rifle, Mack Vance lock with simple trigger
Transitional Rifle, Davis/Jack Haugh Lock, simple trigger
Transitional Rifle, L&R Classic Lock, simple trigger
Davis Jäger lock, and triggers set
Same unset
Davis Hawken lock and triggers set
Same unset
Halfstock, L&R lock & triggers set
same unset
Southern Mountain rifle, Davis lock with L&R Triggers set
Same unset
Boutet flint pistol, L&R Durs Egg Lock
Percussion pistol, Dixie Gun Works, 1950s lock
Hawken pistol, L&R Late English, flint lock
Naval pistol, Dixie Ashmore, flint lock
Average Weight*
818 grams (1.8 lb)
2 lb 10.8 oz
2 lb 10.3 oz
303 grams (.67 lb)
8 lb 2.1 oz
368 grams (.81 lb)
4 lb 6.9 oz
4 lb 9.1 oz
4 lb 8.6 oz
10.4 oz
3 lb 5 oz
1 lb 11.1 oz
1 lb 9.4 oz
1 lb 1.6 oz
3 lb 9.7 oz
Standard Deviation (%)
5 grams (0.6%)
2.7 oz (6.4%)
2.7 oz (6.4%)
20 grams (6.6%)
1 lb 1.0 oz (13.1%)
13 grams (3.5%)
3.8 oz (5.4%)
5.0 oz (6.8%)
4.4 oz (6.0%)**
1.0 oz (9.8%)
4.0 oz (7.5%)
1.0 oz (3.6%)
2.1 oz (8.3%)
0.6 oz (3.4%)
2.3 oz (4.0%)
*1 lb = 454 grams
**Apparently what is happening here is the condition alluded to in the last paragraph on page thirty-eight (operating your DSDL in
single trigger mode because the front blade is contacting the sear arm before the rear blade).
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