Bob Smalser
Member
- Joined
- Apr 1, 2011
- Messages
- 26
I thought I’d write up a few of these that aren’t in the disassembly manuals as they come along.
The gun depicted here is a Model 30G in 20 gauge I restored for use by a grandchild. Sold under a hardware store label of National Firearms Company circa 1915, it has the new model recoil safety lock and pinch-block takedown, but retains the simpler wood and forearm styles of the older Models 16 and 1898. The basic mechanism however, is sufficiently close to other Marlin Hammer Pumps that this can serve as a general guide for disassembly of Models 1898, 16, 17, 19, 21, 24, 26, 42 and 49.
Avoid ordering parts until you are sure you need them, as old guns can be so jammed with century-old oil turned to hard varnish intermixed with concreted powder residue and fragments of old paper shell crimps that a detailed cleaning may be all the gun requires. They all benefit from a thorough soaking in Kroil or other thin penetrating fluid to free up frozen screws and pins. Just try to keep the oil out of the inletting.
Insure the gun is unloaded and the bore is clear. Remove the stock bolt and carefully pull off the buttstock. If you don’t take down the gun first you’ll have better control to gently strike the comb and pistol grip of a reluctant stock alternately with the heel of your hand to prevent the racking that can split out the edges of the inletting. Plus leaving the forearm slide mounted until it’s time to remove the bolt will aid the safety and function checks you’ll perform during disassembly.
My fingers are pointing to the trigger guard screw on the left and the recoil safety lock screw on the right. Loosen the recoil lock screw but don’t remove it yet.
Remove the tension on the hammer. Loosen its mounting screw slightly, compress the hammer spring using your fingers and pull it aside from the roller block on the bottom of the hammer. Then remove the hammer screw and pull the screw from the frame, leaving the hammer loosely in place for now.
Remove both trigger guard screws, pull the trigger guard assembly from the bottom of the frame, reinstall the screws in the trigger guard and the stock bolt screw to keep track of them and set it aside. Pull the loose hammer out the bottom of the frame, remount its screw correctly oriented in its mating hole to keep track of it, and also set it aside.
Note the relationships between the carrier on the left, the recoil lock in the center, the locking bolt atop them, and the safety sear (photo below) still mounted in the frame on the right. Pulling the knurled surface of the recoil lock arm to the rear unlocks the locking bolt above it. Then gently racking the slide arm rearward clicks the bolt out of battery, and moves the carrier downward to pick up the next shell until the carrier arm strikes the shaft of the recoil lock screw. This serves as the rearward bolt stop, which is useful to understand in diagnosing any later problems.
Remount the hammer without the trigger guard and observe the interface between the safety sear and hammer. The hammer has three notches….the upper notch is engaged by the safety sear until the bolt moves forward and locks into battery, whereby a cam slot milled into the bottom of the bolt engages the cam on the top of the spring-loaded safety sear, disengaging it and allowing the hammer to engage the trigger/sear with the full and half cock notches on the lower end of the hammer.
The safety sear can be removed now. It has an integral leaf spring beneath it and pressure should be applied on it with a finger to loosen and pull its screw.
The recoil lock is spring loaded by a plunger that interfaces with the trigger guard frame, and a separate spring-loaded cam on its upper, inside surface that interfaces with a cam slot milled into the carrier.
It functions as an inertia block and must be free to rotate on its shaft. As the gun is fired the frame recoils and the block tips forward, unlocking the locking arm hook from its mating cutout on the bolt, freeing the bolt to be clicked out of battery and racked to the rear using the slide handle. If the shell hangs fire (which is rare today but was common a century ago), the inertia block doesn’t move and the hook prevents the bolt from being racked out of battery without the shooter (hopefully) pausing to think about what happened and wait the required 30 seconds before manually depressing the knurled surface of the locking arm to cycle the action.
Note the hook faces rearward, and the block, cam and carrier/frame mating surfaces are polished for easy movement. The plunger and cam have coil springs and are mounted using pins that facilitate removal for spring replacement and cleaning. When remounting, avoid over tightening the screw.
At the center inside surface of the carrier arm you can see the cutout for the recoil lock’s upper cam. The carrier is removed by dismounting its screw, lifting the arm and pulling it rearward to disengage its positioning slot from the round stud it mates with on the inside link of the locking bolt. Also note if you cycle the bolt rearward, there is no longer a bolt stop mounted and the carrier mating stud will disengage from the track at the rear of the carrier, yet the carrier will appear normal. Try this a few times to see the relationships, as this can cause problems during reassembly.
Now is time to take down the gun. Grab and squeeze the pinch block and pull the magazine tube forward until the left-side detent pin projects outward to hold it in place. Insure the bolt is in battery and pull the slide arm forward and out, disengaging it from the locking bolt link and out of the receiver. Note that the tube’s mounting screw and its corresponding bug (locking) screw are now exposed for further disassembly….the bug screw is removed first and can be accessed by grasping the pinch block and sliding the tube forward slightly. The tube should look like the top photo below.
Loosen the adjusting collar by backing out its screw and if tight, tapping it with a brass hammer. The collar and barrel threads are left-handed, so turn them to the right to loosen and remove the barrel assembly.
Remove the bolt by clicking it out of battery, pulling it all the way to the rear, and rotating the bolt’s tail to the right laterally and clockwise out of the bolt opening. The gun’s locking lug is the rear face of the frame at the bolt opening. If it or its mating surface at the rear of the locking bolt appear to be dinged up or worn, take the gun to a qualified smith and have the headspace checked before test firing. Here I’ve left the safety sear in so you can see the cam that interfaces with a corresponding shaped slot on the bottom of the locking bolt. The vertical slot next to it is the cutout for the carrier arm. Beneath the tip of the pointer is a stopped slot that can make removing and installing the bolt assembly difficult. On the outside of the locking bolt link there is a corresponding stud (photo below) that must be both in the correct position and rotated into that slot for the bolt to fit its track without jamming.
Continued...
The gun depicted here is a Model 30G in 20 gauge I restored for use by a grandchild. Sold under a hardware store label of National Firearms Company circa 1915, it has the new model recoil safety lock and pinch-block takedown, but retains the simpler wood and forearm styles of the older Models 16 and 1898. The basic mechanism however, is sufficiently close to other Marlin Hammer Pumps that this can serve as a general guide for disassembly of Models 1898, 16, 17, 19, 21, 24, 26, 42 and 49.
Avoid ordering parts until you are sure you need them, as old guns can be so jammed with century-old oil turned to hard varnish intermixed with concreted powder residue and fragments of old paper shell crimps that a detailed cleaning may be all the gun requires. They all benefit from a thorough soaking in Kroil or other thin penetrating fluid to free up frozen screws and pins. Just try to keep the oil out of the inletting.
Insure the gun is unloaded and the bore is clear. Remove the stock bolt and carefully pull off the buttstock. If you don’t take down the gun first you’ll have better control to gently strike the comb and pistol grip of a reluctant stock alternately with the heel of your hand to prevent the racking that can split out the edges of the inletting. Plus leaving the forearm slide mounted until it’s time to remove the bolt will aid the safety and function checks you’ll perform during disassembly.
My fingers are pointing to the trigger guard screw on the left and the recoil safety lock screw on the right. Loosen the recoil lock screw but don’t remove it yet.
Remove the tension on the hammer. Loosen its mounting screw slightly, compress the hammer spring using your fingers and pull it aside from the roller block on the bottom of the hammer. Then remove the hammer screw and pull the screw from the frame, leaving the hammer loosely in place for now.
Remove both trigger guard screws, pull the trigger guard assembly from the bottom of the frame, reinstall the screws in the trigger guard and the stock bolt screw to keep track of them and set it aside. Pull the loose hammer out the bottom of the frame, remount its screw correctly oriented in its mating hole to keep track of it, and also set it aside.
Note the relationships between the carrier on the left, the recoil lock in the center, the locking bolt atop them, and the safety sear (photo below) still mounted in the frame on the right. Pulling the knurled surface of the recoil lock arm to the rear unlocks the locking bolt above it. Then gently racking the slide arm rearward clicks the bolt out of battery, and moves the carrier downward to pick up the next shell until the carrier arm strikes the shaft of the recoil lock screw. This serves as the rearward bolt stop, which is useful to understand in diagnosing any later problems.
Remount the hammer without the trigger guard and observe the interface between the safety sear and hammer. The hammer has three notches….the upper notch is engaged by the safety sear until the bolt moves forward and locks into battery, whereby a cam slot milled into the bottom of the bolt engages the cam on the top of the spring-loaded safety sear, disengaging it and allowing the hammer to engage the trigger/sear with the full and half cock notches on the lower end of the hammer.
The safety sear can be removed now. It has an integral leaf spring beneath it and pressure should be applied on it with a finger to loosen and pull its screw.
The recoil lock is spring loaded by a plunger that interfaces with the trigger guard frame, and a separate spring-loaded cam on its upper, inside surface that interfaces with a cam slot milled into the carrier.
It functions as an inertia block and must be free to rotate on its shaft. As the gun is fired the frame recoils and the block tips forward, unlocking the locking arm hook from its mating cutout on the bolt, freeing the bolt to be clicked out of battery and racked to the rear using the slide handle. If the shell hangs fire (which is rare today but was common a century ago), the inertia block doesn’t move and the hook prevents the bolt from being racked out of battery without the shooter (hopefully) pausing to think about what happened and wait the required 30 seconds before manually depressing the knurled surface of the locking arm to cycle the action.
Note the hook faces rearward, and the block, cam and carrier/frame mating surfaces are polished for easy movement. The plunger and cam have coil springs and are mounted using pins that facilitate removal for spring replacement and cleaning. When remounting, avoid over tightening the screw.
At the center inside surface of the carrier arm you can see the cutout for the recoil lock’s upper cam. The carrier is removed by dismounting its screw, lifting the arm and pulling it rearward to disengage its positioning slot from the round stud it mates with on the inside link of the locking bolt. Also note if you cycle the bolt rearward, there is no longer a bolt stop mounted and the carrier mating stud will disengage from the track at the rear of the carrier, yet the carrier will appear normal. Try this a few times to see the relationships, as this can cause problems during reassembly.
Now is time to take down the gun. Grab and squeeze the pinch block and pull the magazine tube forward until the left-side detent pin projects outward to hold it in place. Insure the bolt is in battery and pull the slide arm forward and out, disengaging it from the locking bolt link and out of the receiver. Note that the tube’s mounting screw and its corresponding bug (locking) screw are now exposed for further disassembly….the bug screw is removed first and can be accessed by grasping the pinch block and sliding the tube forward slightly. The tube should look like the top photo below.
Loosen the adjusting collar by backing out its screw and if tight, tapping it with a brass hammer. The collar and barrel threads are left-handed, so turn them to the right to loosen and remove the barrel assembly.
Remove the bolt by clicking it out of battery, pulling it all the way to the rear, and rotating the bolt’s tail to the right laterally and clockwise out of the bolt opening. The gun’s locking lug is the rear face of the frame at the bolt opening. If it or its mating surface at the rear of the locking bolt appear to be dinged up or worn, take the gun to a qualified smith and have the headspace checked before test firing. Here I’ve left the safety sear in so you can see the cam that interfaces with a corresponding shaped slot on the bottom of the locking bolt. The vertical slot next to it is the cutout for the carrier arm. Beneath the tip of the pointer is a stopped slot that can make removing and installing the bolt assembly difficult. On the outside of the locking bolt link there is a corresponding stud (photo below) that must be both in the correct position and rotated into that slot for the bolt to fit its track without jamming.
Continued...