Method of manufacturing of molded firearm part with insert and part
This is a continuation of application Ser. No. 08/233,177, filed Apr. 26, 1994, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     Various firearm parts including frames have in the past been made by molding using non-metalic substances. Serial numbers and other identification have been affixed to certain of such molded parts. 
     SUMMARY OF THE INVENTION 
     Broadly, the present invention comprises a method of manufacturing a firearm part using a multipiece mold with an insert unit which unit is integrally molded into such firearm part. A portion of the insert unit is anchored in a mold recess during molding which portion is thereafter removed. 
     It is a feature that the part so manufactured can be readily marked with a serial number or other identification and that the insert unit is composed of material denser than the molded material. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a side elevational view of a pistol having a molded frame with an insert therein; 
     FIG. 2 is a perspective view of an insert unit prior to and during molding; 
     FIG. 3 is a sectional view along line 3--3 of FIG. 1; 
     FIG. 4 is a sectional view of a pistol frame mold with insert unit formed therein; 
     FIG. 5 is a sectional view along line 5--5 of FIG. 4; 
     FIG. 6 is a perspective view of an alternative insert unit; and 
     FIG. 7 is a sectional view along line 7--7 of FIG. 6. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In FIGS. 1-5, firearm 10 includes slide 11, molded frame 12 including grip frame portion 12a, trigger guard 13, trigger 14 and magazine 16. Horizontal grip recesses 17a-e are also shown in FIG. 1. Insert face plate 20f is seen protruding slightly beyond the frame mold grip portion 12a which face 20f carries the pistol serial number. Frame 12 is made of moldable material preferably a nylon-based plastic. 
     Turning to pistol frame mold as shown in FIGS. 4 and 5, mold 30 includes upper mold half 30a, lower mold half 30b and mold core 30c. Mold half 30b also includes a mold recess 30r for accepting insert unit 20. Insert unit 20 includes insert body 20a, insert skirt 20b and insert prong 20c. Recess 30r functions to locate unit 20 therein and detent units 32, 33 described below apply forces to hold unit 20 in recess 30r. Insert unit 20 is made of a material harder than the molded material preferably a metallic material. Prong 20c is fitted in lower mold passageway 30p. Prong 20c has circumferential groove 20g which together with spring-loaded opposed detent units 32, 33 hold insert unit 20 in place prior to molten plastic introduction, during introduction and during solidification of the plastic which forms frame part 12. Each detent unit 32, 33 includes spring-loaded plunger 32a, 33a which urge balls 32b, 33b into groove 20g. Detent units 32, 33 grip insert prong 20c and hold it to maintain unit 20 in mold recess 30r during the molding operation. 
     After molding is complete, frame 12 including engaged insert unit 20, is taken out of mold 30 by opening mold 30 and applying sufficient force to overcome spring detents 32, 33 to free prong 20c. 
     Following such molding and demolding steps, insert prong 20c is removed by cutting, abrading or other suitable material removable step and thereafter insert body 20a is ground down or otherwise reduced in thickness from T 1  to T 2  (see FIGS. 3 and 4). As reduced, the outer surface of body 30b has planar face 20f. The pistol serial number is then placed on or in face 20f. 
     FIGS. 6 and 7 illustrate an alternative embodiment in which unit 20&#39; includes insert body 20a&#39; includes body fins 20h for further anchoring insert 20&#39; in frame 12.