the firearm disclosed in this application can be used to file pellets or solid projectiles . the pellets would be loaded into a pellet cartridge similar to a typical shotgun shell . when such a pellet cartridge is used , the firearm would operate much like a traditional shotgun , although the pellets would be propelled by compressed gas , instead of an explosive charge . the same firearm can also be used to fire solid projectiles . an adapter would be used to fire a solid projectile . the adapter would resemble a typical shotgun shell , and the adapter would be loaded into the barrel of the firearm in the same basic manner as the pellet cartridge . fig1 shows the barrel , trigger and butt portions of the firearm 1 . the firearm 1 , includes a butt 5 located behind the trigger and trigger guard . fig2 - 4 show cross sectional views , taken along section line ii - ii , which illustrate the interior mechanisms of the firearm as shown in fig2 , a pellet cartridge 2 can be loaded into the firearm . this would be accomplished by breaking open the firearm as shown in fig1 . the pellet cartridge 2 would be inserted into a hole 10 at the rear of the barrel . the barrel would then be closed back into the configuration shown in fig1 and 2 . a typical cylindrical pellet cartridge , as shown in fig8 , includes a plurality of pellets 7 trapped between a rear cover 3 and a front cover 8 . a rear hoop 20 is located at the back end of the cartridge 2 to limit the depth to which the pellet cartridge can be inserted into the barrel of the rifle . the front cover 8 divides the interior of the cartridge into a first space 11 , where the pellets 7 are located , and a second space 12 at the front of the cartridge . in some embodiments , as shown in fig5 and 6 , an expanded diameter cylindrical portion 13 is attached to the exterior rear of the cartridge . a barrel 6 of the firearm ends at a widened portion 24 located at the end 10 of the barrel 6 . the widened portion 24 could receive the rear hoop 20 of the pellet cartridge . the widened portion 24 may also be shaped to accommodate the expanded diameter cylindrical portion 13 of the pellet cartridge shown in fig5 and 6 . a compression chamber 4 is formed in the butt 5 . compressed gas in the compression chamber 4 is used to eject the pellets from the cartridge and down the barrel 6 . when the firearm is fired , the compressed gas presses against the rear cover 3 . the rear cover deforms and advances into the interior of the cartridge and presses the pellets forward against the front cover 8 . the front and rear covers can be made of glass , plastic , paper or other suitable materials . in embodiments that do not use extremely large pressures , the cartridge shown in fig7 and 8 can be used . in other embodiments , where highly pressurized gas is used , a cartridge like the one shown in fig5 and 6 can be used . the pellet cartridge shown in fig5 and 6 includes the expended diameter outer portion 13 which acts to reinforce the cartridge . if the reinforcing were not used , the pressure of the gas could cause the rear end of the pellet cartridge to expand outwards . the exit speed of the pellets can average 180 m / s , depending on the pressure of the gas and the weight and size of the pellets . note , the front cover 8 is spaced back from the front edge of the cartridge . as a result , the front cover 8 separates the interior of the cylindrical cartridge into the first space 11 for receiving the pellets 7 and the second space 12 . when the rifle is fired , the second space 12 guides the pellets 7 as they begin to move , and before they reach the interior of the barrel 6 . the movement of the pellets 7 also forces the front cover 8 to move down the length of the cartridge . before the rifle is fired , the front cover 8 is attached to the interior cylindrical wall of the cartridge at two or more points 14 . in preferred embodiments , the front cover is attached to the interior wall of the cartridge at three points . the attachment between the front cover and the cylinder acts to contain the pellets within the cartridge . but the front cover is also well attached to the cartridge so that a relatively large amount of pressure must build up behind the pellets before the front cover will break away and allow the pellets to travel down the barrel of the rifle . this helps to ensure that the pellets are ejected at a sufficiently high rate of speed . the rear cover 3 also passes down the length of the cartridge when the rifle is fired . the movement of the rear cover down the length of the cartridge ensures that all of the pellets 7 within the cartridge are ejected . as shown in fig3 , when the rifle is fired , the front cover 8 , pellets 7 and rear cover 3 all travel down the barrel and are ejected together . because the pellets and front and rear covers travel down the barrel together , the pellets follow a substantially straight path down the barrel . this , in turn , tends to result in the pellets continuing to follow a straight path after they have been ejected from the barrel . once the rifle has been fired , and the user needs to replace the spent cartridge with a new one , the firearm is opened as shown in fig1 . first notches 9 are formed on the rear of the barrel to make it easy for the user to grasp the left and right sides of the rear hoop 20 at the back of the cartridge . second notches 22 , are cut into the larger first notches 9 to make it even easier for the user &# 39 ; s fingers to get behind the rear hoop 20 of a cartridge to facilitate extraction of the cartridge from the barrel . the first notches 9 and second notches 22 have a crescent shape , which corresponds to the shape of a user &# 39 ; s fingers , to facilitate extraction of a cartridge 2 as mentioned above , the rifle can also be used to fire solid projectiles using an adapter like the one shown in fig9 . to operate the firearm in this manner , the barrel would be opened as shown in fig1 and the adapter 16 would be inserted into the barrel . as shown in fig4 , a slug - like projectile 17 would then be inserted into the adapter 16 . the barrel would then be closed and would be ready to fire . as with the pellet cartridges described above , the adapter could include an additional reinforcing portion 18 which would be accommodated by the widened portion 24 at the rear of the barrel 6 . the front end of the adapter would be beveled to make it easier to insert the adapter into the barrel 6 . typically , the adapter would be made of metal or a metal alloy . the adapter 16 may also include an outer hoop 19 that would further improve its fixation in the interior of the barrel 6 to keep the adapter mounted within the barrel when the barrel is open . any reference in this specification to “ one embodiment ,” “ an embodiment ,” “ example embodiment ,” etc ., means that a particular feature , structure , or characteristic described in connection with the embodiment is included in at least one embodiment of the invention . the appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment . further , when a particular feature , structure , or characteristic is described in connection with any embodiment , it is submitted that it is within the purview of one skilled in the art to effect such feature , structure , or characteristic in connection with other ones of the embodiments . although a number of illustrative embodiments have been described , it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure . more particularly , various variations and modifications are possible in the component parts and / or arrangements which would fall within the scope of the disclosure , the drawings and the appended claims . in addition to variations and modifications in the component parts and / or arrangements , alternative uses will also be apparent to those skilled in the art .