With the mainspring housing now clear of the pistol, push forward (on the back of the receiver) to dislodge the receiver from the front edge of the frame. It is possible that you may need to lightly tap the back end of the receiver with the plastic or wooden mallet again. I was able to remove mine without the need for either.
Lastly, slide the bolt out of the rear of the receiver. A note here....keep an eye on the firing pin stop, which is a pin that goes through the bolt (side to side). While mine didn't appear to fall out easily, I noticed that it could slip out and if one wasn't paying attention, it may go unnoticed and cause issues upon reassembly.
Time for reassembly. It should be noted that most
folks seem to have problems during the assembly process. Getting the main
spring housing back into its proper position is where the difficulties are
encountered. When I first purchased my Ruger Mark1, I encountered a
problem or two myself. I'm
confident in saying that the following steps will make it easier for you.
First, grasp the frame in a natural shooting position. Point the pistol vertically and pull the trigger to allow the hammer to rotate backwards to the cocked position. (it has not yet rotated into the cocked position in the above photo) The hammer all but pivots back flush with the frame when the trigger is pulled. If it doesn't move back, give it a little nudge with your finger. It's possible that the hammer strut is stuck and keeping the hammer from easily moving.
Next step, lower the pistol to the horizontal position and place the barrel/receiver. Slip it onto the frame about 1/16" ahead of its final resting position. Push it to the rear and downwards to engage the forward retaining lug at the receiver's front access ramp (bottom of the receiver).
The receiver is properly aligned when the mainspring pin hole in the receiver is lined up with the hole in the frame. It may take a couple of attempts before you get it properly aligned. If you have difficulty, try rotating the receiver a small amount to get the holes to align. I've read in a forum that it is possible that you may have to place the muzzle on a padded surface in order to press the frame into position to obtain proper alignment. (Mine is not this difficult but I suppose that a new pistol that has not been field stripped very much may offer some resistance.)
Before proceeding any further, inspect the inside of the receiver to make sure the hammer is still in the cocked position (flush in the frame) and that the hammer strut (the little pin that hangs down from the hammer) can move freely. The hammer strut can be clearly seen in the above photo.
After ensuring that the firing pin stop is still in the bolt, insert the bolt into the back end of the receiver/barrel and slide it forward into position. The bolt must be positioned such that the spring is up, as shown in the above photo. The bolt should slide easily into the receiver with no resistance.
OK....you are almost there!
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