You sure you heard "monks"?
These are the rules of Shaolin... I don't know if it applies to
Myanmar monks. Myanmar monks, coming from the Theravada tradition,
has a stricter set of rules. In any case, no monks can deal with
weapons such as guns. Also, Shaolin monks do not use weapons in
actual fighting. Read on and find out.
http://www.taijicommunity.com/OurCommunity/Articles/2003/102003-ShaolinTemple-Part2.html
...It is not surprising that the staff was selected as the core
weapon for the Shaolin monks. As Buddhists, the monks were not
supposed to have anything to do with weapons, but they could
legitimately possess a staff as an aid to walking or a carrying
pole. The Brahmajala-sutra (the Sutra of Brahma’s net) is a
Mahayana work containing ten major and forty-eight minor rules of
discipline and morality. The first rule forbids killing, which
would seem to deny any form of martial activity to the monks.
However, the Brahmajala-sutra also commands all Buddhists to save
all living things from death and suffering. For example, the 16th
precept commands all followers of the Buddha to give up their flesh
to feed starving tigers, wolves, lions, and hungry ghosts. It was
also expected that all devout Buddhists would protect the trinity
of the Buddha, Sangha (priesthood), and Dharma (teachings).
Protecting Buddhist temples, libraries and priests against bandits,
rebels, and invaders would necessitate the use of force, which in
the circumstances soon becomes viewed as justified (Cook, p.17).
The development of warrior monks was not limited to the Shaolin
Temple, Japanese temples also recruited bands of sohei, and Tibetan
monasteries had their own bands of warrior monks who maintained
order and protected the monasteries from intruders...
http://www.shaolin.com.au/weapon5.html

A sturdy and well constructed pipe had more than just "Stick" value
as a non-weapon!

And the Flute was so popular as a hidden or not weapon that there
is even a Fatal Flute Form for Kung Fu training!
Shaolin were Buddhists, mainly. This really did not allow them
to use weaponry against other living beings; not just against
people or anything living, but no items which primary function is
to kill living beings! Yet they trained with weapons! How could
this be?
Shaolin main aim was to achieve enlightenment, preferably in the
current lifetime as Lord Buddha did. This requires prolonged
periods of meditation, preferably between 2 to 6 hours daily.
Unfortunately, this amount of inactivity can cause the Organs,
Circulation and general health to worsen and ultimately collapse.
To prevent this, internal Chi (life force/energy) had to be
strengthened in order to fill your body's reservoir of postnatal
Jing (Life Force)! To be able to do this, three types of exercise
were developed, that originally were one; Kung Fu, Tai Chi and Chi
Kung.
Yet, as the saying goes, 'the capitol is far away', meaning that
safety was always an issue. Even though they were not able to use
weapons against others, they trained weaponry to understand it and
to be able to counter it bare hand. And that is the major reason
for Shaolin Weaponry training.
Although they trained with Weapons, and became very proficient
averaging 4 hours of training a day for 20 years or so (which would
equal 40 years of training 2 hours each day or 4 hours every other
day). yet, to stay fit and to have variety, they developed many
interesting aspects of physical training. It is speculated that
each Monk would be proficient in 18 weapons (not all the same 18)
some specializing further in Projectile, flexible or hidden weapons
to be able to recognize and counter these bare handed. But even the
best sometimes need some 'tools' and the Shaolin developed non-
weapons as these tools.
Some of the more famous of these are;
Monks Lantern
Monks Spade
Walking Staff
Monks Kane
Sash
Bench
Chopsticks
Iron Comb
Flute
Iron Ring
Iron Ruler
Iron Smoking Pipe
Iron Toad
Mandarin Duck Spade
Monk Cudgel
Whip Chain
Rake
Ring Wheel
Scholar's Brush
Pen
Steel Fan
Hoe
Flail
Rope
Chan
Ban Deng
Tie Kuai Zi
Tie Su Zi
Tie Di
Shuo Huan
Tie Chi
Tie Yan Dou
Tie Chan Chu
Yuan Yang Chan
Chan Zhang
Qi Jie Bian
Pa
Lun
Pan Guan Bi
Bi
Tie Shan
Chu Tou

Over the many years, many weapons have been picked up and called
Shaolin. But in reality not that would cut, kill or cripple would
be used. Everyday items, commonly available or usually around would
be favored. In recent years the Bench has come to prominence (in
modern day stool, chair or such). Yet, traditionally, everyday
items like a Sash, Pen and Chop Sticks could be effectively used as
weapons of defence.
So, why the Yin/Yang Symbol for the Weaponry Symbols? because
there are two halves to Shaolin Weaponry training, the simple is to
Learn to use and be proficient with the weapons; the second to lay
the weapon aside and be able to effectively, safely and without
causing harm, disarm the weapon wielder and stop them from hurting
anyone!