Lazarus
28th November 2006, 20:42
I had a number of 1911's built for me, (that was before the big thaw). When new, they all made a swooshing noise when the slide was cycled. The noise was the barrel swooshing inside the slide. I assumed at the time that this was the sound of precision gunsmithing, and I was duly impressed. I now understand that the noise was not the result of any precision fitting, but rather the result of skipping a few of the finishing steps of barrel installation.
Whilst trying to achieve the clearances outlined by Schuemann in his timing test, I marked the barrel and slide to see where the two parts were meeting. Looking at the barrel on axis, it was rubbing the slide at the 4 and 8 o'clock positions all along the chamber end of the barrel. The Kart NM barrel appears to have plenty of extra material along these areas for some reason; but we know that the barrel should not be supported vertically in those places. In fact, if the barrel IS rubbing, it is possible that it does not sit completely down on the frame, resulting in unreliable operation.
After removing a little metal from the barrel sides and from the inside of the slide, I arrived at the fit I was after. The barrel dropped completely within 1/4" of rearward slide movement, but the contact noises (swoosh-swoosh) I had been hearing and feeling were gone. The slide with barrel actually cycles effortlessly (without recoil spring of course) by simply tipping the gun back and forth. That's more like it. Another cheer for Marks-Alot.
Finally, a quick way to find where, in relation to the slide movement, your barrel is hitting the frame VIS. Remove recoil spring and guides and re-assemble everything. Push the muzzle against a table whilst holding the frame in the in-battery position. Now, holding the slide steady, move the frame toward the table as far as it will go. When the frame stops moving, release the pressure on the muzzle and note how far the slide is sitting rearward of its in-battery position.
That's the story.
-Lazarus
Whilst trying to achieve the clearances outlined by Schuemann in his timing test, I marked the barrel and slide to see where the two parts were meeting. Looking at the barrel on axis, it was rubbing the slide at the 4 and 8 o'clock positions all along the chamber end of the barrel. The Kart NM barrel appears to have plenty of extra material along these areas for some reason; but we know that the barrel should not be supported vertically in those places. In fact, if the barrel IS rubbing, it is possible that it does not sit completely down on the frame, resulting in unreliable operation.
After removing a little metal from the barrel sides and from the inside of the slide, I arrived at the fit I was after. The barrel dropped completely within 1/4" of rearward slide movement, but the contact noises (swoosh-swoosh) I had been hearing and feeling were gone. The slide with barrel actually cycles effortlessly (without recoil spring of course) by simply tipping the gun back and forth. That's more like it. Another cheer for Marks-Alot.
Finally, a quick way to find where, in relation to the slide movement, your barrel is hitting the frame VIS. Remove recoil spring and guides and re-assemble everything. Push the muzzle against a table whilst holding the frame in the in-battery position. Now, holding the slide steady, move the frame toward the table as far as it will go. When the frame stops moving, release the pressure on the muzzle and note how far the slide is sitting rearward of its in-battery position.
That's the story.
-Lazarus