referring now to the drawings , wherein like reference numerals designate identical or corresponding parts throughout the several views , it can be seen that the invention is comprised of a receiver 1 with a vertical rectangular slot with rounded corners to prevent the formation of stress risers . the breech block 2 is connected to the lever 3 by a connecting link 23 and two pins 21 and 22 . this causes the breech block to move vertically in the receiver slot in response to rotation of the lever 3 . the barrel 60 is threaded to mate to matching threads on the receiver 1 and is locked into place by a takedown latch 6 attached within the fore stock 57 . the mainspring housing 4 is attached at the rear of the receiver and is threaded to mount a rear stock in a conventional manner using a through bolt . as best seen in fig7 mounting is by a pair of screws 28 , 58 which thread into the housing 4 and are secured by the locking nuts 45 , 59 . access to the locking nuts is through lightening slots ( either cast or machined ) at the rear of the receiver 1 . the cross sectional view in fig2 and 3 show the threaded location on the housing 4 and the end of screw 28 . fig1 shows the action “ ready to fire ”. the stored energy of the mainspring 26 rests indirectly upon the striker 10 , transferred via the socket pin 25 and transfer pin 24 . the striker is supported by the sear 12 and trigger 11 . the striker 10 and trigger 11 both share a common pivot screw 14 which is ground and polished upon its major cylindrical diameter . it is threaded on one end which secures it into the breech block 2 . the safety lever 31 is in its forward “ fire ” position . the safety lever is blocked from view by the lever 3 in fig1 . the safety lever is shown in a different position , but more clearly visible in fig2 . this safety lever 31 pivots upon the pivot screw 32 and a pin affixed on the other end fits a slot in the safety 5 . the safety is under spring pressure from the safety spring 29 and blocked from motion by the cocking pin 13 . the cocking pin has a pair of small springs and guide pins to move it forward , shown respectively as 61 and 62 in fig4 . with the safety on “ fire ”, the action would be fired by pulling the trigger 11 . this action would release the sear , allowing it to rotate upon its sear pivot pin 15 . once freed of the sear , the striker 10 moves rapidly forward . this motion propels the firing pin 9 forward into the primer and firing the chambered cartridge . the firing pin spring 8 is intended to provide a small amount of force to keep the firing pin 9 against the striker as the breech block is lowered to recock the action and reload . replacement of the firing pin bushing 7 , firing pin spring 8 , and the firing pin 9 with suitable alternative rimfire parts allow conversion from center - fire to . 22 cartridges . actions intended solely for . 22 cartridges would use smaller diameter firing pin bushings to prevent ill advised conversion in the reverse . the firing pin bushing 7 can be secured by a friction interference fit , setscrew , or cross pin . the use of the bushing simplifies the machining of the breech block 2 , allowing the use of investment castings . this provides a solid metal barrier in the event of a ruptured cartridge case or primer . alternately breech blocks may be manufactured from solid stock , but requires the addition of shield plate 17 and screw 16 as shown in drawings to offer similar protection . the shield plate 17 also acts as a cover for a pair of springs and pin bushings to keep the cocking pin 13 at its most forward positions . the recommended method to return the safety to its “ safe ” position is to lower the muzzle and slowly lower the lever 3 . if done with moderate restraint , the shell will return to the chamber and when the lever is again raised , the action will be loaded with the safety in the “ safe ” position . fig3 shows the cocking wedge 33 which is attached within the receiver by the screws 34 and 35 . the symmetrically mounted wedge and screws which are their complement are not shown . these cocking wedges cause the cocking pin 13 and striker 10 to be cammed , simultaneously , towards the rear of the breech block 2 . the safety 5 is spring driven by 29 upwards to block the cocking pin and striker . the same spring 29 pushes the sear return pin 30 which provides the sear 12 with a minimal return force . during the breech block &# 39 ; s downward travel , the lever 3 rotates with the extractor 19 remaining at rest as in fig1 . near the final 10 ° of travel , a molded internal surface on the lever makes contact with a projecting step on the extractor 19 . the slotted extractor is initially forced at an upwards angle , with spring pressure from the extractor spring 20 guiding the extractor into contact with the shell rim . the extractor , being cammed upwards by the lever creates considerable mechanical advantage . the tangential forces of contact with the case rim are redirected causing the cartridge to be moved rearward slightly and accomplishes primary extraction in a positive , but relatively effortless manner . near the bottom of the breech block &# 39 ; s travel ( see fig5 ), a spring 43 retained by setscrew 44 forces the ball 42 ( see fig5 ) into the detent at the rear of the trigger 11 . this causes the trigger to be rotated slightly counterclockwise and the sear to come to rest underneath the lower left corner of the striker . the extractor begins rotation when the extractor &# 39 ; s slot makes contact with the lever pivot 18 ( either screw or pin ). the freed cartridge case is then fully removed by continued rotation of the lever . at the fully opened position , the extractor has continued in an arc such that is does not make contact with a fresh cartridge during reloading . the slot in the extractor will allow it to slip over the shell rim during a later stage of operation when the lever and action are again closed . the action has been recocked and the safety lever will automatically be returned to its “ safe ” position . fig2 shows the action and components in the fully open position . the mainspring 26 and socket pin 25 are captive , at rest against the setscrew 27 . there are no forces exerted upon the transfer pin 24 except that of potential energy due to gravity . at this time with the bore inclined , ( approximately 45 ° or greater ), the action can be closed with the mainspring completely isolated from the hammer and firing mechanisms . this will hopefully avoid potentially hazardous conditions and accidents that occur when people try to release the mainspring tension by dry firing or other variations . even in the unlikely case of a cartridge stuck in the chamber , this action is rendered safe . for a check , the lever will close and can be moved with minimal effort . with the muzzle safely lowered below horizontal and pointed in a safe direction , a cartridge can be inserted into the chamber of the barrel . once reloaded , the action would be closed by pulling the lever back and upwards . during the upward motion of the breech block 2 , the transfer pin 24 rests upon the receiver 1 and against the striker 10 until it slips into the ( hemispherical , conical , etc .) depression on the back of the striker . at the same time the trigger ( 11 ) is moving upward , the ball ( 42 ) spring ( 43 ), and setscrew 44 , which function as a ball plunger cause the trigger to rotate clockwise blocking the sear underneath the striker . with further upwards movement of the breech block 2 , this spring ball plunger provides a small forward force on the trigger 11 . this holds the mechanism in position while the transfer pin 24 and mainspring 26 are engaged into the depression on the striker 10 . after it has engaged , the transfer pin continues in an upward arc while its rearmost end pivots upon the socket pin 25 to compress the mainspring 26 until fully compressed as shown in fig1 . fig3 shows a cutaway view of the takedown latch assembly . it is attached to the forearm hanger 41 by a pin 40 located at its most rearward position nearest the receiver . the latch rotates upon this pin freely and a spring 37 places pressure to hold it against the adjustment screw 36 . the adjustment screw is directly threaded into the forearm hanger . the adjustment screw is turned outward by means of an allen wrench . the wrench is passed through a bushed hole 38 through the stock and a narrow slot on the bottom side of the latch , into the head of the screw itself . the rounded head of the screw bears upon a matching concave surface on the inside of the takedown latch . the rearmost projection of this latch is chambered to index itself into the slot provided at the front of the receiver ( as shown in fig6 ). the pin 39 , longer than the slot width itself , is rotated in an arc until both ends rest upon each side of the slot . this places pressure between the barrel and receiver , adjusting for minor thread wear , and locks them into desired final position . fig9 shows a cutaway view of fig8 the barrel assembly as it would appear removed from the receiver 1 . the stock hanger 41 is directly attached to the barrel by screws 52 , 53 , 54 , and 55 . these are mirrored symmetrically by the location of screws 48 , 49 , 50 , and 51 which secure the scope base 56 to the barrel . the locating of the screws as such is intended to offset effects of uneven expansion or contraction upon the barrel . the mounting of the stock 57 is by two screws , the stock screw 46 and the front swivel screw 47 . the present invention provides an improvement in a falling breech block single shot action for a firearm where the mainspring and its housing are directly attached to the receiver . the rear of the mainspring housing is threaded for a stock screw . the striker and trigger are attached to the breech block . connection is made by the transfer pin fitting into depressions on the hammer and socket pin of the mainspring . the striker and trigger use the same pivot screw . this significantly reduces misalignments caused by the combination of locating and manufacturing tolerances of each individual part . this allows precise manufacture of the rifle action without requiring excessive trigger over - travels or adjustment screws . the present invention further provides an improvement in a falling breech block single shot action where the safety mechanism is automatic in operation and completely blocks the striker . this safety is so incorporated into the breech block requiring only three additional components to be added to the action . in addition , the present invention provides an improvement in a falling breech block single shot action where the firing components and the mainspring are separable in a single operation . this is to relieve tensions on the mainspring and allows for increases in safety regarding storage . also , the extraction of fired cartridge cases is positive and operates in a smooth manner . the few required components are robust , rather uncomplicated , and do not project forward of the receiver . the takedown and extractor only require the loosening of the latch mechanism and one screw to allow removal of the barrel and extractor for the purposes of storage , transport , or changing to different barrel assemblies / calibers . the method of attachment of the forearm stock allows easy takedown , while limiting potential effects on accuracy and durability . the forearm hanger is mounted to the barrel directly opposite the scope mounting bases . this placement reduces the effects of barrel expansion upon accuracy while allowing a relatively free floated forearm with strong attachment locations for both stock and swivels . although only an exemplary embodiment of the invention has been described in detail above , those skilled in the art will readily appreciate that many modifications are possible without materially departing from the novel teachings and advantages of this invention . accordingly , all such modifications are intended to be included within the scope of this invention as defined in the following claims . having thereby described the subject matter of the present invention , it should be apparent that many substitutions , modifications , and variations of the invention are possible in light of the above teachings . it is therefore to be understood that the invention as taught and described herein is only to be limited to the extent of the breadth and scope of the appended claims .