trigger 3

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blueprints gunsmithing

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141"'/64 die~ 3/16 deep

1 1/8

3/16

+

~iTI"\-

D

# 10-32

1/8 I I-I 2 places1/4

3/32

#30 drill3 places.for rivets.(Use the sideplafefora drill template.)

FRONT SPACER BLOCKmat'l - Aluminum or CRS

1 required

Face "l" (see text)

drill2 places for rivets.(Use the side platefor a drill template.)

REAR SPACER BLOCKmat'l - Aluminum or CRS

In this trigger system, the triggerand the sear are separate parts. Thetrigger bar supports the front lip ofthe sear (refer to Figure 3) in a mannerthat the sear is prevented fromrolling forward, so the sear notch(a part of the striker in the bolt) isprevented from moving forward tofire the cartridge. When the shooterpulls the trigger rearward, the pivotedtop end of the trigger bar moves outfrom under the sear nose, allowing

1 the sear to roll over forward under

the pressure of the striker spring.With the striker notch movedforward, the sear is returned to theupright position by the sear spring.

The trigger spring in the upperhole in the front spacer block witha tensioning screw provides anadjustable trigger tension, andreturns the trigger to its uprightposition under the sear nose whenthe trigger is released after firing.

When the bolt is withdrawn afterfiring, the sear notch rides over thetop leg of the sear, forcing the seardown, pushing the rear end of thesystem housing downward, allowingthe bolt assembly to go rearward.As the sear notch passes rearwardover the sear top, it allows the searand the housing to rise again intoposition in front of the sear notch.When the bolt is again moved forwardchambering the fresh cartridge, thesear notch is again held back incocked position by the sear forthe next firing.

An over-travel screw in the rearspacer stops the trigger after it hasreleased the sear and preventsexcessive rearward travel of thetrigger pull. The engagementadjustment screw in the bottom ofthe front spacer block adjusts theamount of engagement of the triggerwith the sear, preventing an overlong

trigger pull. The W' holes in the sideplates allow easieradjustment ofengagement and provide accessforlubrication. Engagement of thetrigger bar with the sear nose by onlyabout 0.020" permits a smooth butabrupt let-off for firing.

The trigger assembly is not subjectedto heavy forces by recoil causedby firing, but the trigger and searare required to securely preventthe accidental firing of the rifledue to any bump or jolt inany direction.

The adjustment must all be ableto securely prevent release of thefiring mechanism - tested beforeever loading the firearm. Test itthoroughly, jolted and bumpedsolidly, in all possible directions,with the chamber empty while thestriker notch is engaged to makesure the firing mechanism cannotaccidentally release. Also, safetyrequires you occasionally do thistest to make sure the trigger systemis safe before taking the weaponto the field for shooting.

Now, Let's Make One

But first, one or two notes. Sincethis sear/trigger combination is allthat prevents the rifle from firing,it must be carefully made ofadequate aluminum or steel andthe engagement faces need to behardened steel. The failure of anystressed part can allow an accidentalfiring, so be sure of your work. Thehousing does not directly receivefiring stresses; the forces appliedwithin the assembly are all of lowmagnitude. Wear on the trigger barand sear can result in failure, andthese parts should be hardened steelat their contact parts.

Since Mausers have been made bymany manufacturers, and to manyspecifications from customers, it ismandatory that you first verify all themeasurements given to make surethey will fit properly and do theirfunctions as designed. I have foundvariations from one maker to anotherand you may too. And, the sear mustengage fully with the striker notch.

Now, let's proceed. This is not acomplicated mechanism, but each parthas its function, so study how theyinteract before starting to cut metal.

October/November2001 27

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