Blank firing conversions for semiautomatic pistols

Claim 2

In a pistol including: a frame having a camming surface; a slide reciprocally mounted on said frame between a forwardmost position and a rearmost position; and a barrel including a barrel chamber portion, a barrel element and a lower supporting surface, said barrel being supported by said frame in at least a first forward position of said barrel by engagement of said camming surface of said frame with said lower surface of said barrel, said barrel defining an abutment surface engageable with said slide upon rearward movement of said slide such that said slide causes corresponding rearward movement of said barrel to a second rearward position thereof, wherein upon rearward movement of said barrel to said second rearward position said supporting surface of said barrel disengages said camming surface of said frame to permit at least a rear chamber end of said barrel to move downwardly to a loading position to receive a cartridge; the improvement comprising: a modified replaceable barrel having a modified supporting surface defining a reduced length such that said modified supporting surface prematurely disengages from said camming surface of said frame to permit said rear chamber end to move prematurely downwardly at a position forwardly displaced from said second rearward position of said barrel to a loading position where a cartridge may be loaded within said barrel, said modified barrel including a modified abutment surface dimensioned and positioned to be engaged by an engaging surface of said slide during rearward movement of said slide at a position rearwardly displaced from said forward battery position of said slide to drive said barrel rearwardly to said second rearward position, said modified abutment surface being oriented at an oblique angle relative to a longitudinal axis of said barrel element.

Claim 3

The pistol of claim 1 wherein the angle of said abutment surface relative to said longitudinal axis is less than about 45°.

Claim 4

The pistol of claim 1 including a restrictor member positioned within said barrel element of said modified barrel and having a constricted bore dimensioned and configured to generate sufficient back pressure in said barrel upon firing of a blank cartridge to move said slide to said rearmost position.

Claim 5

The pistol of claim 1 said modified abutment surface of said barrel is defined at the juncture of said barrel chamber portion and said barrel element.

Claim 6

In a pistol including: a frame having a camming surface; a slide reciprocally mounted on said frame between a forwardmost position and a rearmost position; and a barrel including a barrel chamber portion, a barrel element and a lower supporting surface, said barrel being supported by said frame in at least a first forward position of said barrel by engagement of said camming surface of said frame with said lower surface of said barrel, said barrel defining an abutment surface engageable with said slide upon rearward movement of said slide such that said slide causes corresponding rearward movement of said barrel to a second rearward position thereof, wherein upon rearward movement of said barrel to said second rearward position said supporting surface of said barrel disengages said camming surface of said frame to permit at least a rear chamber end of said barrel to move downwardly to a loading position to receive a cartridge; the improvement comprising: a modified replaceable barrel having a modified supporting surface defining a reduced length such that said modified supporting surface prematurely disengages from said camming surface of said frame to permit said rear chamber end to move prematurely downwardly at a position forwardly displaced from said second rearward position of said barrel to a loading position where a cartridge may be loaded within said barrel, said modified barrel including a modified abutment surface dimensioned and positioned to be engaged by an engaging surface of said slide during rearward movement of said slide at a position rearwardly displaced from said forward battery position of said slide to drive said barrel rearwardly to said second rearward position, said modified abutment being generally transverse to a longitudinal axis defined by said barrel element and being disposed at a position intermediate a forward chamber end and said rear chamber end of said barrel chamber.

Claim 7

In a pistol including: a frame having a camming surface; a slide reciprocally mounted on said frame between a forwardmost position and a rearmost position; and a barrel including a barrel chamber portion, a barrel element and a lower supporting surface, said barrel being supported by said frame in at least a first forward position of said barrel by engagement of said camming surface of said frame with said lower surface of said barrel, said barrel defining an abutment surface engageable with said slide upon rearward movement of said slide such that said slide causes corresponding rearward movement of said barrel to a second rearward position thereof, wherein upon rearward movement of said barrel to said second rearward position said supporting surface of said barrel disengages said camming surface of said frame to permit at least a rear chamber end of said barrel to move downwardly to a loading position to receive a cartridge; the improvement comprising: a modified replaceable barrel having a modified supporting surface defining a reduced length such that said modified supporting surface prematurely disengages from said camming surface of said frame to permit said rear chamber end to move prematurely downwardly at a position forwardly displaced from said second rearward position of said barrel to a loading position where a cartridge may be loaded within said barrel, said modified barrel including a modified abutment surface dimensioned and positioned to be engaged by an engaging surface of said slide during rearward movement of said slide at a position rearwardly displaced from said forward battery position of said slide to drive said barrel rearwardly to said second rearward position, said modified abutment being generally transverse to a longitudinal axis defined by said barrel element and being disposed at a position intermediate a forward chamber end and said rear chamber end of said barrel chamber.

Claim 10

The method of claim 6 wherein said step of altering said original abutment surface includes removing said original abutment surface to define said modified abutment surface wherein said modified abutment surface is positioned between about 0.050 inches and 0.150 inches from the position of said original abutment surface.

Claim 11

The method of claim 6 wherein said step of altering said original abutment surface includes forming said modified abutment surface wherein said modified abutment surface extends generally transverse to a longitudinal axis defined by such barrel element.

Claim 14

The method of claim 9 further including altering the original abutting surface of said barrel unit to define a modified abutting surface, said modified abutting surface defining a plane oriented at an oblique angle relative to a longitudinal axis of said barrel element and configured and dimensioned to be engaged by said abutment surface of said slide upon rearward movement of said slide to a position displaced from said forwardmost position such that said slide generates sufficient momentum to move said barrel unit rearwardly to said second rearward position thereof.

Claim 15

The method of claim 9 wherein said step of reducing the length of said lower surface of said cartridge feed ramp includes reducing the length by from about 25% to about 75%.

Claim 18

The method according to claim 12 further including the step of positioning a restrictor element in said barrel element, said restrictor element defining a constricted opening dimensioned to generate sufficient back pressure in said barrel unit upon firing of a blank cartridge to move said slide to said rearmost position.

Claim 19

The method according to claim 12 wherein said step of altering the original abutting surface includes forming said modified abutting surface having said plane defining an angle less than about 45° relative to said longitudinal axis.

Claim 20

The method according to claim 14 wherein said step of altering the original abutting surface includes forming said modified abutting surface having said plane defining an angle of ranging from about 8° to about 15° relative to said longitudinal axis.

Claim 21

The method according to claim 12 wherein said step of providing a pistol includes providing said barrel unit including a barrel hood extension extending from said barrel chamber portion and having a predetermined length and width and wherein said method further includes the step of reducing the length of said barrel hood extension a predetermined distance.

Claim 22

The method according to claim 16 wherein further including the step of reducing the width of said barrel hood extension a predetermined distance on a case ejection side of said barrel hood extension.

Claim 23

The method according to claim 17 wherein said step of providing a pistol includes providing said barrel chamber portion with a chamber mouth for reception of a cartridge, said chamber mouth defining a generally circular cross-section, and wherein said method further comprises the step of forming a bevelled arc adjacent said chamber mouth to facilitate ejection of a cartridge, said bevelled arc being disposed adjacent said case ejection side of said barrel hood extension.

Claim 24

The method according to claim 18 wherein said step of providing includes providing said barrel hood extension with a circumferential arc adjacent said chamber mouth, and wherein said method further comprises the step of forming a bevelled relief cut on said barrel hood extension adjacent the circumferential arc and adjacent said case ejection side of said barrel hood extension.

Claim 25

A pistol formed in accordance with the method of claim 10.