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A well-made .22-caliber air rifle that really packs a punch!
by Tom Gaylord
Airgunners,
being a fickle lot, always want what isn't available. When RWS
brought out their astonishing 350 Magnum breakbarrel spring rifle,
they originally made it only in .177 caliber. This monster airgun
was advertised as being capable of exceeding 1,200 f.p.s., which
was an advertising coup, to be sure. That explains the .177 caliber,
which gets higher velocities from lighter pellets. But almost
from the moment it was announced, airgunners were asking for
the .22 version, and not without good reason.
While 1,200 f.p.s. sounds impressive, experienced airgunners
know it's best to keep the terminal velocity of diabolo pellets
below the threshold of the sound barrier for best accuracy. Any
object traveling at or above the speed of sound (a variable velocity
that remains around 1,100 f.p.s. at sea level) creates a wave
of pressure through which it must pass. That wave is disruptive
to shapes not streamlined for supersonic flight - which the diabolo
pellet definitely isn't. The pressure wave causes the pellet
to flutter in flight, resulting in demonstrably wider dispersion
at any given range. And, when the pellet slows to below the sound
barrier, it has to pass through its own turbulence once again.
Faster isn't always better!
Diabolo pellets, with their light weight, open skirts and pinched
waists, are very susceptible to the disruptions of the sound
barrier. They were designed specifically for subsonic velocity,
where they perform admirably.
So, when a magnum air rifle wants to toss them out the spout
at supersonic speeds, the wise shooter knows to shoot only the
heaviest pellets, thus slowing things down. That's the case with
the .177 350 Magnum, which turned out to be surprisingly accurate
with the right (heavy) ammunition. Hunters quickly accepted it
as one more special all-powerful spring rifle they could turn
to. But, they knew it would be even more special in .22.
A large-caliber bore often has more energy than its smallbore
sibling without changing anything but the barrel. It's not unusual
to have as much as a 10 percent increase in power when the barrel
is changed from .177 to .22. That's an increase in power, not
velocity. A 12 foot-pound rifle in .177 caliber shoots a 7.9-grain
pellet at 826 f.p.s., which works out to about 11.97 foot-pounds.
Rebarreling the same rifle in .22, it might shoot a 14.3-grain
pellet at 645 f.p.s. or 13.21 foot-pounds. That's almost a 10
percent power increase from nothing more than rebarreling the
gun.
In a supermagnum like the RWS 350, the difference between small
and large calibers can be truly remarkable. In a test conducted
by The Airgun Letter in July 2001 with a new .177 350
Magnum, we saw a top muzzle energy of 20.87 foot-pounds. That
was a 10.5-grain Crosman Premier pellet averaging 946 f.p.s.
In our subject .22-caliber test rifle, the same model and powerplant
turned in 24.38 foot-pounds! Some of the difference is because
two different guns were involved (this was not a rebarreling
of a .177, but a brand new rifle in .22 caliber), but it's still
a whopping 14 percent power increase. And the fun just starts
there.
At the 350 Magnum's velocity, .22 caliber is a really useful
hunting rifle! When you have more than enough power to get kicked
off any field target range in the world, you also have the kind
of trajectory most people expect only from a .177. Experience
shows that diabolos are best if kept below 900 f.p.s. Usually,
that kind of speed is only a dream for a breakbarrel .22, but
not for our test rifle. Below are the velocity figures we got
after a break-in of a few hundred rounds.
|
Muzzle 1' from the start screen · 73 degrees F Oehler 35P chronograph · All strings were 10 shots |
|||||
|
14.4 grains |
14.5 grains |
21.1 grains |
12.2 grains |
14.3 grains |
|
| High | 848 f.p.s. | 893 f.p.s. | 685 f.p.s. | 943 f.p.s. | 852 f.p.s. |
| Low | 827 f.p.s. | 860 f.p.s. | 664 f.p.s. | 861 f.p.s. | 809 f.p.s. |
| Average | 834 f.p.s. | 870 f.p.s. | 674 f.p.s. | 904 f.p.s. | 831 f.p.s. |
| Extreme spread | 21 f.p.s. | 33 f.p.s. | 21 f.p.s. | 82 f.p.s. | 43 f.p.s. |
| Standard deviation | 6 f.p.s. | 10 f.p.s. | 6 f.p.s. | 24 f.p.s. | 14 f.p.s. |
| Muzzle energy | 22.25 ft.-lbs. | 24.38 ft.-lbs. | 21.29 ft.-lbs. | 22.15 ft.-lbs. | 21.93 ft.-lbs. |
What is especially exciting about the above is the good speed for the Beeman Kodiaks. At almost 700 f.p.s., the trajectory will be reasonably flat out to 35 yards, and the Kodiak is often one of the most accurate pellets in a spring rifle. That's especially true in a powerful airgun like this, where pellets with thin walls and skirts tend to be deformed by the violent air blast. Kodiaks have a smaller skirt diameter and fit into the breech with ease. Their 21-grain weight is a plus on target. The pure lead composition guarantees excellent performance on thicker-skinned animals such as crows and woodchucks, where deep penetration is a plus.
The 350 has great genes
& descends from a family of powerful spring guns
The 350 Magnum is the latest in a series of high-powered
spring rifles from RWS. Starting with the model 45, which was
followed by the model 34/36/38 breakbarrels that were introduced
in the mid-1980s, RWS was always at the forefront of the power
race for spring air rifles. If they weren't in first place at
some particular time, they were vying to get there.
When the model 34 came out, it set the stage for things to come.
It was followed by the model 36 and 38, which had checkered beech
and walnut stocks, respectively. These first magnum models were
all the same except for the woodwork, and the plain-jane 34 lives
on today as the top seller of the entire line. But breakbarrels
are just part of the RWS lineup.
When Beeman and Weihrauch collaborated on the design of the R1
breakbarrel to capture the power record in 1982, RWS responded
a few years later with the even more powerful 48/52 sidelever
rifles. Both share identical powerplants, but the 48 is the plain
uncheckered version while the 52 has the fancier stock. For a
time, they were the hands-down power champs of factory spring
rifles - and they are still top-selling models for the Nürnberg-based
maker - but the new 350 Magnum is even more powerful than all
these earlier bruisers. And it is larger, too.
The 4' overall length of our test gun not only makes it a large air rifle, it dwarfs other so-called big firearms like the M1 Garand and the 1917 Enfield rifle. Among spring piston guns, it has few equals in either size or power. Only the Gamo 1250, the Webley Patriot and the Theoben Eliminator play in the same ballpark. The 350M weighs a surprisingly light 8.2 lbs., give or take for the density of the wood. I say surprising because this is lighter than many lower-powered spring rifles such as the Beeman R1 and even the Air Arms TX 200. Yet it doesn't feel like a light rifle at all. It feels very much like a Springfield M1903 - heavy and solid - the feel of reliability most spring-gun shooters long for.
Like
the '03 Springfield, this is a purposeful rifle, not a general
plinker. It's not to be rushed, but it will do the job every
time. For instance, consider cocking and loading. Like all breakbarrels,
the 350 breaks open to cock the mainspring and to load a pellet
into the breech. Cocking effort is a relatively light 36 lbs.
of effort, measured by placing the muzzle on a bathroom scale
and pressing down on the butt until the sear catches. This is
the same force required to cock a factory Beeman R1 that produces
about 17 foot-pounds of muzzle energy - four to seven less than
the 350. And our test showed there was no measurable drop in
cocking effort as the gun broke in. After a custom lubrication,
it might become a trifle easier - but it's pretty much on the
beam as it comes from the box.
Most super-powerful breakbarrel rifles have a heavy chisel-shaped
detent with a powerful locking spring that requires slapping
the muzzle to open the breech, but the 350 does not. It uses
the same ball-bearing detent that has been the mainstay of RWS
breakbarrels for decades and the Diana rifles they sprang from
for decades before that. It keeps the barrel securely closed
until you cock the rifle, when it pops open with a light breaking
action. When you close the barrel again, it snaps shut with a
fluid click.
Speaking of the breech, the barrel is deeply counterbored to
receive the pellet more readily than most breakbarrels. RWS/Diana
rifles have always had a somewhat slanted breech face, which
has caused the deformation of the lower part of the pellet skirt
when the barrel was closed, but this new relieved breech seems
to take care of that. You can insert the pellet so deep into
the bore than no part of the skirt sticks out to catch on anything.
One more thing to notice at the breech is the rear sight. Diana
was a pioneer with a rear sight element featuring four quickly
interchangeable notches that can be adapted to a number of different
front globe inserts. The sight itself is click-adjustable for
both windage and elevation. We found it necessary to move the
rear sight to the left and up a few clicks to zero the gun at
20 yards with Kodiaks. On any gun - firearm or airgun makes no
difference - the rear sight has to move in the direction you
want the strike of the round to move.
Up front is a globe sight that accepts replacement inserts.
When you buy the rifle there is a post insert installed and there
are no additional inserts packed with the gun, but RWS should
be able to supply them if you really need them. Since most folks
will opt for a scope, the maker doesn't want to pour a lot of
money into a throwaway item. The rectangular post is the most
appropriate for this kind of rifle, as long as the rectangular
rear notch is also used.
Because the open sights are so good on this rifle, they were
used for initial range testing. A wide range of .22 pellets was
used in the first range test, and most were reasonably accurate.
At 10 yards, groups hovered around 0.30" to 0.50" for
five shots center-to-center. This is good accuracy for open sights,
especially on an unfamiliar rifle whose hold has not yet been
learned. More time would have been spent refining the hold except
for one thing. With Beeman Kodiak pellets, the group size shrank
to less than half the size of the other pellets. Clearly, it
was the pellet to pursue.
At 20 yards, Kodiaks grouped like other pellets did at 10 yards.
And, remember, this is with open sights! It was obvious the 350
wanted to shoot well, and the Kodiak pellet was part of the equation.
For those outside the U.S., the Kodiak is the name Beeman gives
to the H&N Baracuda.
A word about why
the Kodiaks were chosen when they were not the most powerful
pellets through the chronograph. Magnum spring rifles (especially
the 350!) deliver a powerful blast of air to the base of the
pellet before it starts down the bore. This has been demonstrated
to force the thin skirts of lightweight pellets out against the
walls of the bore, something called "blowing out the skirts."
Pellets recovered from water traps show this condition very clearly.
Heavier pellets with thicker skirts and pellets made of a hard
lead alloy (e.g., Crosman Premiers) do not tend to have blown-out
skirs. That often results in better accuracy.
Already accurate with
open sights, imagine what it will do scoped!
So the 350M is an accurate rifle with open sights
- how much better will it do when scoped? That was our next test.
Scoping a powerful spring rifle requires some thought. The springer
is the gun that gave airguns a reputation for breaking scopes,
so you don't want to install something old or of dubious quality.
Fortunately, the bad experience that spring-piston airguns gave
to the riflescope designers in the 1970s and '80s made them go
back to their drawing boards to strengthen their products. Forget
the .50 BMG rifles - they aren't the ones breaking scopes. Spring
rifles are - or were, before the manufacturers learned they had
to brace their optics to withstand recoil in both directions.
Today, most scope manufacturers make a product that holds up
well even with notoriously hard-recoiling airguns.
That said, be sure to use modern scopes on your spring guns
- and it doesn't hurt if they have the parallax adjustment down
to 10 yards, either. That's the sign of a true airgun scope.
We chose an RWS model 450 scope for our test. It's a 3-9x variable
with parallax adjustment down to 7.5 yards. That makes it an
easy scope to sight in, as you can walk to within 10 FEET of
the backstop to be sure you're on paper with the first shot.
The bull will be quite clear if you leave the scope on low power
and dial the parallax as close as it will go. Remember to wear
shooting glasses when doing this, as you will be hit with flying
lead fragments at such a close distance!
The scope ramp on
the 350 Magnum is equipped with a hole into which a scope stop
pin will fit, but the diameter of the hole is on the small side.
The stop pins found on some scope bases are too large to fit,
but B-Square makes a separate scope stop that has a two-diameter
pin that can be switched to fit most rifles.
An alternative to using the RWS stop hole is to butt the rear
scope ring base against the large-diameter screw head at the
rear of the ramp. I have used this as a scope stop many times.
One airgunner told me that his hard-kicking RWS sidelever sheared
off the screw head this way, and that's something you don't want
to do.
Another alternative scope stop is also available from B-Square.
They make a stop pin with a flat on one side for the BSA spring
rifles. You can hang this pin off the front of the scope ramp
and mate the flat of the stop pin to the front of the ramp. Doing
it this way means your front ring base will only be halfway on
the scope ramp, which may disturb some people - but it works.
I've done it this way a couple of times with no difficulty.
Other brands of mounts have small pins that fit the RWS hole.
I selected a Beeman 5030 mount made by Sportsmatch for this test.
Though this mount is not adjustable, the barrel on the 350 Magnum
was aligned close enough to the line of the ramp that a lot of
scope adjustment wasn't needed. The Sportsmatch stop pin is small
enough to fit the hole, too, which is all-important with this
rifle.
Whatever you do, use a scope stop of some kind on this rifle.
Clamping pressure won't hold your mounts in place. The only time
clamping pressure holds by itself on a recoiling air rifle is
when the pressure is so great that either the receiver/scope
ramp of the rifle or the scope base is distorted, and the metal
of one or the other deforms to create a mechanical stop. This
has been tested on light-recoiling spring guns repeatedly, always
with the same results. Use a positive mechanical scope stop and
leave the clamping scope rings to pneumatic and gas-powered airguns,
where there is little movement on firing.
Squeeze the most amount
of accuracy from this rifle by using the "artillery"
hold
Our 350 Magnum proved to be somewhat sensitive
to hold, which was expected because of its power level and the
fact that it's a breakbarrel. When shooting a sensitive spring
rifle, always hold it as loosely as possible and let the gun
move and recoil as much as it wants. Place your off hand under
the forearm at the same place for every shot. This sets up the
same vibration patterns from shot to shot. Never rest the forearm
on anything except the flesh of your hand. Even sand bags will
not give good results with a recoil-sensitive airgun.
When I say to let it recoil as much as it wants, I really mean
it. Hold the gun with no pressure exerted by your cheek and shoulder
and only your thumb opposing the trigger finger. The other fingers
of the shooting hand should not touch the gun. While this sort
of hold sounds a bit extreme, it is the same hold that top benchrest
shooters have used for decades. Their bullets exit the barrel
in one or two milliseconds, and they still hold light. You have
to wonder why.
The reason for the light hold is to influence the rifle the least
amount possible and still maintain control. No one can hold a
recoiling pellet rifle hard enough to prevent it from moving
when it fires. Even if the rifle were clamped in three steel
vices it would move.
The movement you see and sense is caused by two different recoil
forces at work in a spring rifle. When the sear breaks and the
piston starts moving forward, the rifle moves in the opposite
direction with the same force. Since it weighs many times what
the piston weighs, it takes time for the force pushing on it
to get it moving. And the movement is small because of the weight
differential. But a second recoil force is many times larger
and can be felt easily - especially in a spring gun as powerful
as the 350 Magnum.
The piston continues forward, compressing the air in front of
it until there is a cushion of high-pressure air that's only
a few thousandths of an inch thick. The piston seal will not
allow this air to escape past the end of the piston, and the
pellet in the rear of the barrel will not allow it to escape
forward through the barrel. The piston, which weighs many ounces
and is pushed by a mainspring having over 100 lbs. of energy,
comes to a complete stop when the air pressure in front of it
is greater than it's remaining energy. At that moment, the pellet,
which has been sitting at the rear of the barrel with air pressure
on its tail increasing rapidly, is finally overcome and starts
to travel down the bore. But, it's the piston we're interested
in at the moment.
When the piston stops going forward, it does so just as suddenly
as if it had hit a brick wall. The energy transferred to the
air cushion in front of the piston has to go somewhere, and the
slow-moving pellet cannot absorb it all. A large percentage of
the energy is therefore transferred directly to the air rifle,
just as if the piston had hit solid steel. That jolt becomes
a FORWARD recoil that makes the initial rearward recoil seem
non-existent by comparison. It is this forward recoil that often
broke scopes because they weren't braced for it.
This two-way recoil has been extensively discussed in the literature
for many decades. Several years ago it was widely believed that
a firm hold was the way to control a spring air rifle, but today
we know different. A human being simply cannot control spring-gun
recoil forces completely and to try to is to invite marksmanship
disaster. You cannot repeat a firm hold exactly the same, as
the muzzle will always be in a slightly different place when
the pellet comes out.
As powerful as these recoil forces are, it would be possible
to cancel them entirely by extensive heavy clamping. Even if
you could, you cannot stop the barrel from moving. That's what
many do not fully appreciate or understand.
The barrel doesn't just move in recoil. It also vibrates! This
vibration is the movement that is virtually impossible to restrain.
It's also the reason why it's almost impossible to completely
silence a spring-powered airgun. The powerplant vibration transmitted
through the metal of the gun partly turns to sound. No barrel-mounted
silencer can quiet this sound, which often comprises about three-quarters
of the noise a spring gun makes. A better way to quiet a spring
gun is through tuning, which removes excess vibration and the
noise that accompanies it.
Let's get back to our lesson on rifle accuracy. Because it's
impossible to restrain or eliminate the movement and vibration
of a spring rifle, the best we can do is standardize movements
so they always occur the same way. That way, the pellet will
always exit the muzzle with the rifle in the same position, and
that has been demonstrated to produce the best potential accuracy
in any airgun. It works for firearms, too.
The way we standardize a rifle's movement, both big and little,
is by always holding it in the same way. Always rest the forearm
on the open palm of the off hand at the same place every time.
Always apply the same amount of pressure at the buttplate, the
cheekpiece and the pistol grip. The closer you get to applying
no pressure at all, the easier it is to repeat it.
Several years ago, I called this kind of hold the "artillery"
hold, because it reminds me of a field artillery piece. The barrel
of a field cannon may move several feet in recoil, but the gun
carriage stays in place. With a spring rifle, you become the
gun carriage. A field artillery piece can repeatedly hit a target
miles away, so this crazy method really works.
I may have come up with the name, but I did not invent the hold.
Lucian Cary wrote about it in the 1940s, and marksmen have used
it much longer than that. You can see examples clear back in
the days when Creedmoor was new, and it may already have been
old at that time. It takes practice and experimentation to get
good at it, but I can almost guarantee you'll reduce your benchrest
group size by 50 percent if you learn to use it.
If you forget everything else, here is the key to shooting tight
groups with any rifle: the shooter must hold the rifle with as
little external influence as possible. Relax and let the gun
go limp in your hands. This is not for hunters or soldiers but
for marksmen who want the absolute best accuracy that can be
had from a hand-held gun.
A hunting gun that shoots as well
as a 10-meter target rifle!
If you use a good hold with the 350 Magnum and scope it well,
it responds with nice, tight groups. When I scoped our test rifle
and returned to the range, I was surprised! The Kodiak pellets
that had shot best with open sights were not doing best with
a scope mounted. They did well, but not as good as I had hoped
from the earlier range session. I worked for a long time before
finally recognizing the rifle was not going to group better than
about a half-inch at 25 yards. Granted, that's as good as many
.22 rimfires can do, but the 350 is capable of so much more.
I finally accepted the results and began trying the other pellets
in my case. When I got to the domed Benjamin/Sheridans, my search
ended. Of the entire lot of pellets, they emerged as the clear
champions, producing groups at 25 yards that were tighter than
some groups at 10 meters with open sights. Though this pellet
is on the hard side, perhaps the power of the 350 Magnum needs
the extra hardness to resist deformation from the air blast.
This pellet is very close to the Crosman Premier in shape, weight
and lead alloy. I would expect similar performance from Premiers.
Of course you may find an even better pellet through experimentation. No test report like this is ever as thorough as the owner of a gun who lives with it day in and day out. I have found that shooting technique will improve over time, especially if you shoot just the one gun. Soon, you will fall into the right hold on the first shot and from then on, your groups should be as good as they can ever be.
Summary
There are more high-powered spring air rifles
than ever on the market today. The 350 Magnum has earned a place
of distinction among them. Buy this rifle for its features rather
than its price, though it is very competitive on both accounts.