Читать книгу The Gun Digest Book of Firearms Assembly/Disassembly Part V - Shotguns - J B Wood - Страница 9

Benelli Model 121 M1

Similar/Identical Pattern Guns The same basic assembly/disassembly steps for the Benelli Model 121 M1 also apply to the following guns:

Benelli Standard Autoloader

Benelli Model 121 Slug

Data:	Benelli Model 121 MI
Origin:	Italy
Manufacturer:	Benelli Armi,S.p.A.,Urbino
Gauge:	12
Magazine capacity:	7 rounds
Overall length:	39-3/4 inches
Barrel length:	19-5/8 inches
Weight:	7 Ibs. 3 oz.

The Benelli semi-auto shotgun has an unusual action, using neither gas nor long recoil. Instead, it has a prop-type locking bar that is released by a rebounding bolt head-a unique system. Importation and sales in the U.S. were formerly handled by Heckler & Koch, Inc. The present importer is Benelli U.S.A..

Disassembly:

1. Loosen the cross screw in the magazine tube hanger loop at the muzzle, and slide the hanger off toward the front. Cycle the action to cock the internal hammer, and set the safety in the on-safe position. Unscrew the knurled retaining nut at the front of the forend, and the nut and the sling loop toward the front. The nut unscrews counter-clockwise (front view).

2. Remove the barrel, upper receiver, and forend toward the front. It the gun is new and tight, it may be necessary to pull the bolt half-way back and release it several times, to start the assembly forward.

3. Tip the rear of the forend wood away from the barrel, and remove the forend downward and toward the rear. Remove the spacer ring and spring ring from the recess at the front of the forend. The rings will be released as the wood is taken off, so take care that they aren't lost.

4. Move Ihe bolt all the way to the rear of the receiver, and pull out the firing pin retainer toward the right. A f ingerna il notch is provided in the head of the T-shaped retainer, and no tools are needed. Remove the firing pin and its return spring toward the rear.

5. Remove the cocking handle toward the right, and remove the bolt assembly toward the rear. The ejector, which is also the bolt guide, is welded in place inside the receiver, and is not removable.

6. Remove the locking bar from the underside of the bolt carrier, outward and toward the rear.

7. Remove the bolt head from the front of the bolt carrier. Remove the heavy bolt head spring toward the front.

8. The extractor and its coil spring are retained on the right side of the bolt head by a vertical roll pin. Restrain the extractor, and drift out the pin in either direction. Remove the extractor and spring toward the right.

9. The recoil spring connector strut is retained at the lower rear of the bolt carrier by a cross pin that is riveted on both sides. Unless removal is necessary for repair, this pin should be left in place.

10. Drift out the roll pin at the lower rear of the lower receiver, directly above the safety. Push the carrier latch, and tip the carrier up to its raised position. Use a nylon-tipped drift punch to nudge the trigger group downward at the rear. Be sure the carrier stays elevated, or it will be damaged.

11. When the trigger group is free, remove it downward and toward the rear.

12. Grip the front of the carrier spring guide firmly, and move it toward the rear to detach it from its cross pin in the carrier dog. Slowly release the spring tension, and remove the guide, spring, and spring base from the trigger group.

13. The carrier pivot is retained on both sides of the group by C-clips, but only one has to be taken off. Remove the C-clip from either side, restraining it as it is pried from its groove to prevent loss. Remove the carrier pivot from the trigger group.

14. Remove the carrier upward.

15. The carrier dog pivot is easily removed, and the dog is then detached from the carrier. The pivot is held in place by the side of the group unit when the carrier is in place, and is freed as the carrier is taken off, so take care that it isn't lost.

16. Move the safety to the off-safe position, pull the trigger, and ease the hammer over forward, beyond its normal fired position. The hammer spring and follower can now be removed upward.

17. Pull out the hammer pivot toward the right, and remove the hammer upward.

18. Restrain the trigger, and drift out the trigger pin toward the right.

19. Remove the trigger assembly upward. The trigger spring is easily detached from the front of the trigger. The secondary sear, or disconnector, and its plungerand spring can be removedfromthe trigger by pushing out its cross pin. Caution: Control the plunger and spring as the pin is taken out

20. Hold a fingertip over the hole on top of the group at the rear to arrest the safety spring, and drift the small cross pin at upper rear toward the right until the hole is cleared. Remove the safety spring and plunger upward, and push out the safety button toward either side. If the plunger fails to come out with the spring, tap the trigger group on the workbench to free it. The other small cross pin at the rear of the group is a limit pin for the trigger. It retains no part, and need not be removed in normal takedown.

21. The carrier latch and its spring are retained inside the right wall of the lower receiver by a vertical pin which is pushed out upward. Only half of the lower tip of the pin is accessible, and a very small screwdriver or an opened paper clip should be used to push the pin. Restrain the carrier latch.

22. After the pin is pushed out, remove the carrier latch from the lower receiver. The spring is easily detached from the carrier latch, if necessary.

23. An ordinary socket wrench can be used to remove the nut under the buttplate that retains the stock. The exact size of the nut is 13mm, but if no metric socket is available, a standard 1/2-inch socket will work. Take off the nut, lock washer, and spacer washer, and remove the buttstock toward the rear..

24. Drifting out the vertical roll pin at the rear of the recoil spring housing will release the stock mounting bolt for removal toward the rear. Caution: The stock bolt is also the retainer for the recoil spring, so restrain it during removal Take out the spring and follower toward the rear. No attempt should be made to remove the spring housing or the magazine assembly from the lower receiver.

Reassembly Tips:

1. When replacing the safety button in the trigger group, remember that the end with the red band goes on the left side.

2. When replacing the carrier spring base in its recess on the left side of the trigger group, note that the hole in the base is off-center. The end nearest to the hole must go toward the outside-that is, to the left. Also, the flat face of the base goes to the front.

The bolt head must be pushed to its rear position in the carrier before the cocking handle can be reinserted.

When replacing the two rings in the front of the forend, the plain ring goes in first, and the spring ring at the front.

When moving the barrel and receiver assembly toward the rear, be sure the rear tip of the recoil spring strut on the bolt carrier engages the cup of the spring follower.