Basically this is a mod for mechanical pencil gun because I made one of these and It started to banana peel so I made this version witch is cheeper to make and last a lot longer. ( it dose help if you make the other gun first and use it until it dies)

Step 1: What You Need

somthing to cut with
several kinds of tape
straws
rubber band
bic pencil (or mod a piece of wood or w.e)

Step 2: Making Ramming Thingy...

(If you already made the first version of this and destroyed the original barrel then just take the ramming thing out of old barrel and skip this steep )

take apart pencil

Step 3: Making New Barrel

This is simple just cut bendy part of both straws off then make 4 cuts about 1/2 inch long at base
and insert into other straw
(Tape together)

make sure a bb/ air soft can easly roll down*

Step 4: Renforcing Barrel

this is realy easy just rap in several layers of tape so the straw dosent break when you fire it.
(the more tape the better)

*make sure you look at all notes on pictures*

Step 5: Finishing Barrel

now you need to cut off extra tape and about 1/4 of an inch of straw from taped end

you also may want to cut some extra off the other end of barrel not more than 3inch

Step 6: Prepair to Fire!

insert the rod from the pencil and add ruber bands

if your mentaly retarded it shoots bbs and other simular things put bb in front then bull back pencil part aim and fire (let go)