Merlyn 1008:Firing Line 0107

Merlyn 1008:Firing Line 0107
19/8/08
14:28
Page 73
Testing the
Daystate
Merlyn
NIGEL ALLEN unveils
the trickery inside
Daystate’s new
Merlyn
s
’
e
t
a
t
s
c
i
y
g
a
a
D M
T
The Merlyn is
a looker
hink Daystate these days and you
automatically think of their electronic,
computer controlled hardware. Since the
inception of their MK.3 just over five years
ago, there have been a number of variant
models, each pushing the boundaries of the IT-based
airgun – a road which, surprisingly, other
manufacturers have yet to go down. In 2008 alone,
I’ve tested three new motherboard-driven Daystates
for Air Gunner: the Grand Prix, and Tactical and
MVT variants of the Air Wolf.
The irony, though, is that this Staffordshire-based
gunmaker – universally heralded as the founder of
modern-day precharged airgunning – built its
reputation on traditionally styled air rifles,
which were well engineered and rugged
enough to withstand tough field
assignments. Although there’s been the odd
eye-catcher, up until a few years ago, there
weren’t many Daystate models which would
win first prize in a beauty contest! They were
guns for shooting, not ogling.
Though Daystate build sporters, which look
every bit as good as they shoot and handle, they still
turn out mechanically-driven rifles, i.e. those that
don’t run off computer technology.
The Merlyn is probably the belle of them all – and
the sort of rifle every airgunner would want on their
wish list. This model has been around for about five
years, but the latest version, which hasn’t been given
any form of Mk. II tag to distinguish it from its
forebear, is a very different piece of kit. In profile,
there are a few new lines which share a
commonality with the MK.4 family – but go
inside... and things are very different indeed.
While many airgunners (and some
manufacturers) are prepared to accept that
conventional PCP technology has gone
about as far as it can, Daystate has
The manometer shows how air pressure you
have left. A full charge will return 130 – 160
shots per charge thanks to the regulated system
rewritten
the
books
by
taking
mechanically-driven design into a whole
new era – and they’ve done it without a
chipset or battery to be seen.
SLINGSHOT SYSTEM
More accurately, they’ve done it with the
aid of renowned airgun technician, Steve
Harper. Inside the Merlyn – and destined
for other Daystate models any day soon –
is a unique new hammer/valve set-up
based on Harper’s patented ‘slingshot’
system. Totally mechanical, this ingenious
piece of engineering improves the
efficiency of the action to such an extent
that it’s actually comparable with the
original MK.3 computer-gun – the CDT
action of which, of course, was seen as a
massive step forward when it launched
five years ago.
What this effectively means is that
you’ve got a mechanical rifle with all the
advantages of a computerised one –
efficient use of air, high shot count, flat
power curve and ultra-fast firing cycle. For
the electronic sceptics out there, that’s
something to take very seriously.
A detailed description of the slingshot
AIR GUNNER 73
Merlyn 1008:Firing Line 0107
19/8/08
14:34
Page 74
ADAPTED FROM Steve Harper’s Patent
drawings, this illustration demonstrates how
the Merlyn’s ‘slingshot’ hammer works. The
top diagram shows the rifle in its cocked state,
with the entire hammer held back against its
mainspring (1) by the sear (2) of the trigger
(10).
The beginning of the firing cycle, when
you release the trigger, is shown in the lower
diagram. The mainspring drives the hammer
forward until its outer cage (11) comes to an
immediate halt upon hitting the O-ring buffer
(16) on the valve block (13). But the inner
hammer (12) continues travelling forward
under inertia, striking open the valve (7) so
that compressed air (8/9) escapes through the
transfer port to launch the pellet (17b) up the
bore.
At this point, the open valve is
immediately shut courtesy of its return spring
(4) and the compressed air (8). This starts a
reverse travel of the inner hammer (12), and
this backward motion is further aided by the
hammer’s own return spring (14). When the
reversing inner hammer hits the cage’s
internal buffer washer (18), much of its kinetic
energy is dissipated – so when the internal
hammer tries to bounce forward again, the
tension of the return spring (14) is enough to
stop it from doing so.
This means there’s no chance of the valve
stem being hit a second time (and more), thus
avoiding unnecessary releases of air long after
the pellet’s started up the bore; effectively
there’s just the one air transfer. The result is
massively improved air efficiency and a far
greater shot-count per fill-up of air.
The Harper
Slingshot
hammer and all
important valve
assembly shown
in the graphic
left
The action removed from the stock.
It looks very conventional, but
inside is the magic valve assembly
system is shown in the panel above, but to
put it in one sentence, Harper’s slingshot
hammer mimics the operation of a
solenoid-powered valve hammer and,
therefore, eliminates the phenomenon
known as ‘hammer bounce’.
In a conventional PCP, hammer bounce
causes a constant opening and closing of
the valve subsequent to the main
discharge, thereby letting out air long after
the pellet’s begun its journey. This
unnecessary air release is simply wasted.
The practical advantages Harper’s
anti-bounce system brings are numerous.
Firstly, because no air is being ‘lost’ with
each trigger-pull, you get far more shots
per fill-up of compressed air – and my .177
test Merlyn returned 130 usable shots
from a meagre 180-BAR charge. Daystate
74 AIR GUNNER
NB: Daystate’s technicians slightly ‘re-interpreted’
Harper’s Patent when developing the Merlyn’s
hammer/valve system. Because O-rings are for sealing, not
shock-absorbing, they did away with the buffer O-ring (16)
and achieved the dampening effect by modifying the
material of the hammer cage (11). They’ve also
incorporated a free-floating, self-centring valve seat at point
‘a’. Because this effectively takes up any wear, it greatly
reduces the chance of the Merlyn’s valve ever leaking air.
claim a .22 would give 160. Looking back at
my notes from 2004, when I put an
unregulated Merlyn in .22 through its
paces, I clocked up 108 shots. That’s a shotcount improvement of over 45 per cent.
Because there’s no hammer and valve
‘bouncing’ going on, the firing cycle of the
new Merlyn certainly felt much quicker
than I remember, and much sweeter. I
commented to Daystate on there being a
lack of ‘rocket’ effect – where the muzzle lifts
at the shot – and their technical people told
me this was another benefit of the slingshot
system; there’s no extraneous air following
up the pellet when it exits the muzzle.
And a fourth benefit became apparent
over
the
chronograph.
Although
unregulated, the new Merlyn has a power
curve – the rise and fall of muzzle energy
between the first and lost shots – of just
0.25 ft. lb. Most unreg’d PCPs show a curve
of between 0.5 and 1 ft. lb., which I guess
is the reason why the all-new Merlyn won’t
be offered with a regulator, as you could
opt for on its earlier version.
All these advantages sound good on
paper and I can certainly vouch for them
on the range, too. It’s definitely with
handling in mind that the stylish looks of
the Merlyn’s right-hand, thumbhole
walnut stock have been developed by
creator, Gary Cane – and the performance
that comes courtesy of its revamped action
is quite something.
My favoured hunting rifle is an
electronic Air Wolf, and I can honestly say
that I switched over to the Merlyn’s
mechanical action with little difficulty. Its
Merlyn 1008:Firing Line 0107
19/8/08
14:35
Page 75
Testing the
Daystate
Merlyn
MERLYN – FACTS
MANUFACTURER:
Daystate, UK.
CONTACT:
☎ 01782 791755.
TYPE:
Multi-shot sporter.
ACTION:
Bolt-action, precharged pneumatic, unregulated.
CALIBRE:
.177 (4.5 mm.) and .22 (5.5 mm.).
MAGAZINE:
10-shot, rotary, removable. Single-shot tray
option (not supplied).
FILL PRESSURE:
Up to 200 BAR (2,400 p.s.i.).
SHOTS PER CHARGE:
.177 – 130 (tested at 180 BAR);
.22 – 160.
OVERALL LENGTH:
992 mm. (39 ins.).
BARREL LENGTH:
432 mm. (17 ins.).
WEIGHT:
4.1 kg. (9 lbs.) (with supplied scope).
TRIGGER:
Two-stage, fully-adjustable, curved blade.
SAFETY:
Manual, rocker-type, resettable.
STOCK:
Ambidextrous thumbhole sporter, American
walnut with rosewood pistol grip cap.
LENGTH OF PULL:
350 mm. (13.75 ins.).
POWER:
11+ ft. lbs. (15+ J).
PRICE:
From £670 incl. VAT. Price includes QD
charging connector and magazine.
(Thumbole rifle on test - £899.)
fast, vibration-free lock time and the ‘still’
muzzle definitely did their bit to make the
Merlyn feel very ‘dead’ and, therefore,
totally recoilless on firing. The lack of any
significant power curve showed itself
through the rifle’s outstanding results at
the target. Whether I was shooting at the
beginning, end or mid-way point of the
charge, I never had any inkling of the
shots striking high or low of centre;
whatever I was aiming at, I felt confident
of hitting.
The Merlyn’s outstanding performance
is too good not to be utilised in the field,
where its balance, pointability and antireflective finish complement its many
other hunting-friendly attributes a treat.
Shooting either ‘thumb up’ or ‘through’,
I found the luxurious thumbhole
woodwork suited me whether I was prone,
kneeling or standing. The long fore-end
gives your leading hand plenty of grip
options, and as much as I’d have liked to
have seen some stippling somewhere to
match the pistol grip’s, I can’t help
thinking it would ultimately spoil the
Merlyn’s flowing lines.
The stock allows the shooter
to shoot with ‘thumb up’ or
‘thumb through’. It looks
pretty cool as well
spread the load and make the break-point
feel lighter than it actually is. I liked the
look of its set-back style, but also found it
tended to scrunch up my trigger finger
when shooting with my thumb ‘through’
the stock.
The bolt doesn’t need much effort to
pull back – though I found it best to give
it a short, sharp ‘yank’ when using the
auto-indexing, 10-shot mag. Be too gentle
and you run the risk of a double-load –
though this won’t be a problem if you
change the magazine for the optional
single-shot pellet tray.
Auto-loading firepower comes courtesy
of the removable, rotary magazine
(supplied) which you insert into (and
remove from) the breech from the left or
right according to where you position its
stop-pin. It’s the new, low-profile unit – so
you’ll have few scope-mounting problems –
which now features the magnetic ‘anchors’
to keep the chambers perfectly aligned
with the breech.
The Merlyn has Daystate’s standard
quick-fill charging system at the front of
the main cylinder, accessed after pulling off
its protective dust cap, and there’s a gauge
viewable through the belly of the fore-stock
so you can keep an eye on your air.
Secreted at the business end is a
specially-machined aluminium baffle, the
purpose of which is two-fold. It deflects the
air emerging before and after the pellet
backwards, into the void of the full-length,
19 mm. diameter barrel shroud. This
‘soaks up’ any muzzle crack. It also ‘settles’
any turbulence between the muzzle of the
inner bore and the end of the shroud which
overhangs it by 100 mm. It worked well –
the rifle’s report was muted below my
aural range and, as I previously
mentioned, the down range accuracy was
very confidence-boosting.
I’m really impressed with the latest
Merlyn – and although this tasty-looking
sporter might not be within reach of
everyone’s pocket, it definitely marks the
beginning of yet another new ‘Daystate
era’ in terms of PCP technology. And
given the slingshot hammer is going into
other models in their portfolio, I’d say
this forward-thinking Staffordshire
outfit now has the precharged market
pretty much sewn up at both ends –
mechanical and electrical.
CRISP TRIGGER
I’m sure the trigger’s been modified over
earlier versions because it felt a lot crisper.
Backed up by a resettable, manual safety
catch, it’s an adjustable, two-stage affair
with a wide-faced blade. This helps it
AIR GUNNER 75