Ruger MKII Dis/Re-assembly Instructions

Problem / Cause / Solution

1) Problem:

click to enlarge I can't pull the bolt back more than 1/2".

Cause:

click to enlarge Hammer strut (A0100, top arrow) is not seated into Main Spring Plunger (KA02509) Cup properly and is catching on the Sear Spring Stop Pin (A02603, bottom arrow). Which will prevent the Hammer from being fully cocked, which will keep the bolt from moving rearward more than about 1/2".

Solution:

click to enlarge Unlock and swing out Main spring housing (first half of step 3). If you have tried to pull the bolt back then you have pushed the Hammer strut under the cross pin. This can keep you from removing the main spring housing. To correct this pont the pistol down, pull the trigger and while holding the trigger back shake it a bit to get the hammer to fall. Then you should be able to remove the main spring housing. Then CAREFULLY READ and follow steps 11 to the end.

2) Problem:

click to enlarge click to enlarge I have the Bolt Stop Pin (A00100) up into the reciever all the way, but when I try to swing the main spring housing closed it wants to pull down out of the reciever (like on the left, not the right). click to enlarge

Cause:

click to enlarge The hammer is not in the forward position, it is in the cocked position, and the main spring housing it hitting the hammer or the strut. In the pic you can see that the hammer is cocked (laying flat back into the receiver out of view) and the hammer strut (A0100) is probably laying on the Sear Spring Stop Pin (A02603). The hammer should be in the forward position for inserting and removing the Main Spring Housing.

Solution:

CAREFULLY READ and follow steps 11 to the end.

3) Problem:

click to enlarge I have the reciever on the frame but now I can not insert the bolt into the reciever very far.

Cause:

click to enlarge The hammer is in the forward position and is blocking the path of the bolt.

Solution:

click to enlarge Push the hammer to the rear from inside the ejection port so that it lays all the way flat to the rear. You will have to point the barrel up while doing this so that the hammer strut (A0100) does not catch on the Sear Spring Stop Pin (A02603) and keep it from being pushed all the way back. Notice how the hammer strut goes over the Sear Spring Stop Pin and rests on it when the hammer is all the way cocked back. Insert Bolt, pushing it all the way forward, then CAREFULLY READ and follow steps 11 to the end.

4) Problem:

click to enlarge I have everything back together and now when I pull the bolt back, let it drop, and pull the trigger, I don't get the click.

Cause:

click to enlarge Hammer strut (A0100) is not seated into Main Spring Plunger (KA02509) Cup properly. This will not give you any spring pressure on the hammer, and thus it will not drop when you pull the trigger.

Solution:

click to enlarge Unlock and swing out Main spring housing (first half of step 3), then CAREFULLY READ and follow steps 11 to the end.

Cause 2:

click to enlarge Disconnector is not popping up to engage the sear. (This can be seen when looking at it with the receiver off and main spring housing in, but when testing the trigger this way make sure to catch the hammer and not let it hit the frame) The disconnector should move freely, and not be gritty at all. It is supposed to rise up under spring tension by the trigger spring.

Solution 2A:

If you can hold the pistol upside down and the disconnector drops to engage the sear properly, then you likely left out the trigger spring, or need a new one (this is what pushes the disconnector up into the sear).

Solution 2B:

If 2A did not work, then look to see what is keeping the disconnector from popping up, something in this area may have developed a burr, or foreign object that may need to be cleaned out.

5) Problem:

click to enlarge I have pulled out the tab on the main spring housing, but it will not swing out all the way (only goes as far as the pic to the left).

Cause:

You did not drop the hammer first, it is still cocked.

Solution:

Get the hammer to go forward. You can accomplish this by pulling the trigger and pushing on the back of the hammer or hammer strut with a screwdriver, or by pointing it in the air and getting the hammer strut to engage the main spring housing again and while pushing it closed pull the trigger. Once you get the hammer forward the main spring housing will open.

6) Problem:

click to enlarge I can't push the bolt in all the way (ignore the arrow in the pic)".

Cause:

click to enlarge The "ears" (left part in the pic) of the Recoil spring and guide assembly (part KA-57 top part in pic to the left) may be bent out a little.

Solution:

A temporary fix may be to bend them back together, but I would recommend getting a new Recoil spring and guide assembly from Ruger