Carrier guide and firearm

Abstract

Firearms having a carrier assembly, buffer systems, and methods, having a carrier spindle, carrier saddle, or both, to reduce carrier tilt or wobble, reduce wear, or both. A carrier spindle can be located forward of the buffer spring, buffer weight, or both, and aft of the carrier assembly, and can slidably engage the carrier assembly. A spindle spring can bias the carrier spindle aft from the carrier assembly. In some embodiments, a taper on the carrier spindle facilitates separation of the lower receiver from the upper receiver. In some embodiments, the spindle spring is a helical spring that is loaded in compression and pushes the carrier spindle aftward. Some embodiments include a carrier saddle that supports the aft end of the carrier assembly. The carrier saddle can be raised, have a concave top surface, be made of a softer material, have dimensions within certain ranges, or a combination thereof.

What is claimed is: 
     
         1 . A firearm comprising:
 a carrier assembly;   a carrier spindle that is at least partially aft of the carrier assembly, wherein the carrier spindle slidably engages the carrier assembly; and   a helical spindle spring located between the carrier spindle and the carrier assembly that pushes the carrier spindle aftward, away from the carrier assembly, wherein the helical spindle spring is loaded in compression.   
     
     
         2 . The firearm of  claim 1  further comprising a buffer weight aft of the carrier spindle and a main buffer spring aft of the buffer weight. 
     
     
         3 . The firearm of  claim 1  further comprising a main buffer spring aft of the carrier assembly wherein the main buffer spring is stiffer than the helical spindle spring. 
     
     
         4 . The firearm of  claim 1  wherein the carrier spindle fits inside the carrier assembly when the firearm is assembled. 
     
     
         5 . The firearm of  claim 1  comprising a barrel through which bullets are fired, wherein: the carrier spindle comprises a length parallel to an axis of the barrel, a forward end, and an aft end; the aft end has a larger major lateral dimension than the forward end; and the forward end has a uniform major lateral dimension over a majority of the length of the carrier spindle. 
     
     
         6 . The firearm of  claim 1  wherein: the carrier spindle comprises a forward end and an aft end; the aft end comprises a taper; the firearm comprises an upper receiver and a lower receiver; and the taper pushes the carrier spindle forward when the upper receiver is separated from the lower receiver. 
     
     
         7 . The firearm of  claim 1  wherein: the firearm comprises a buffer tube; when the firearm is discharged, the carrier spindle guides the carrier assembly into the buffer tube; and the carrier spindle acts to reduce carrier tilt within the firearm. 
     
     
         8 . The firearm of  claim 1  further comprising a raised carrier saddle that supports an aft end of the carrier assembly. 
     
     
         9 . A firearm comprising:
 a carrier assembly having an aft end;   a buffer spring that biases the carrier assembly forward; and   a raised carrier saddle that supports the aft end of the carrier assembly.   
     
     
         10 . The firearm of  claim 9  further comprising a buffer weight aft of the carrier assembly, wherein the buffer spring is aft of the buffer weight. 
     
     
         11 . The firearm of  claim 9  wherein the firearm comprises an upper receiver and a lower receiver and the lower receiver comprises the raised carrier saddle. 
     
     
         12 . The firearm of  claim 11  wherein the raised carrier saddle is integral with the lower receiver. 
     
     
         13 . The firearm of  claim 9  wherein: the firearm comprises a buffer tube; and when the firearm is discharged, the raised carrier saddle guides the carrier assembly into the buffer tube. 
     
     
         14 . The firearm of  claim 9  wherein the raised carrier saddle acts to reduce carrier tilt within the firearm. 
     
     
         15 . The firearm of  claim 9  wherein the raised carrier saddle comprises a concave top surface that supports the aft end of the carrier assembly. 
     
     
         16 . The firearm of  claim 9  wherein: the raised carrier saddle comprises a top surface that supports the aft end of the carrier assembly; and the raised carrier saddle comprises an overall top surface lateral dimension that is between 25 percent and 75 percent of an overall lateral dimension of the carrier assembly at the aft end. 
     
     
         17 . The firearm of  claim 9  wherein: the raised carrier saddle comprises a top surface that supports the aft end of the carrier assembly; and the raised carrier saddle comprises an overall top surface longitudinal dimension that is between ⅛ inch and an overall lateral dimension of the carrier assembly at the aft end. 
     
     
         18 . The firearm of  claim 9  wherein the raised carrier saddle consists of a material having a significantly lower hardness than a hardness of the carrier assembly at the aft end. 
     
     
         19 . The firearm of  claim 9  wherein:
 the firearm comprises an upper receiver and a lower receiver; 
 the lower receiver comprises the raised carrier saddle; 
 the lower receiver comprises a buffer tube; 
 when the firearm is discharged, the raised carrier saddle guides the carrier assembly into the buffer tube; 
 the raised carrier saddle acts to reduce carrier tilt within the firearm; 
 the raised carrier saddle comprises a concave top surface that supports the aft end of the carrier assembly; 
 the raised carrier saddle comprises an overall top surface lateral dimension that is between 25 percent and 75 percent of an overall lateral dimension of the carrier assembly at the aft end; and 
 the raised carrier saddle comprises an overall top surface longitudinal dimension that is less than the overall lateral dimension of the carrier assembly at the aft end; and 
 the raised carrier saddle consists of a material having a lower hardness than a hardness of the carrier assembly at the aft end. 
 
     
     
         20 . A firearm comprising:
 an upper receiver;   a lower receiver comprising a buffer tube;   a carrier assembly located in the upper receiver, the carrier assembly having an aft end;   a buffer spring located in the buffer tube in the lower receiver and aft of the aft end of the carrier assembly; and   a raised carrier saddle that supports the aft end of the carrier assembly wherein: when the firearm is discharged, the raised carrier saddle guides the carrier assembly into the buffer tube and the raised carrier saddle acts to reduce carrier tilt within the firearm.