Barrel Cylinder Gap

[kBob]

Reading the discussion on proper barrel cylinder gap and how to make it the same every time got me to thinking and playing.

It seems to me the answer is in the barrel wedge screw. When the wedge is driven fully against the screw it was not possible for me to turn the screw. When the wedge was loose s was the screw.

So try this and get back to me on how it worked.....

With wedge driven out to allow it to hold but not release the wedge, and with the wedge retaining screw turned fully down, Back the wedge retaining screw four full turns out. Drive the wedge all the way in until It is locked by the wedge spring against the retaining screw.

Measure the Barrel cylinder gap. If it is to wide, drive out the wedge and drive the retaining screw back in one full revolution or a measurable part there of ( like 1/4 turn or ½ turn or3/4 turn) If the gap is too small, drive the wedge loose and back the screw out in a like manner.
Drive the wedge home an lock the screw again and try another feeler gauge.

Keep track of the total number or fractions of turns. Write it down. This should (I hope ) allow you to remove the screw during cleaning and then turn it back to the same position for reassembly.

Does this make sense?

-Bob Hollingsworth

 

[Voodoochile]

I've never thought to try this before because I usually use the palm of my hand to seat the wedge & then turn the cylinder to see if it is too loose or too tight & adjust accordingly.

My thoughts are that even though you may not be able to turn the wedge retaining screw with the wedge seated against it, will it stay put under recoil?

 

[mykeal]

If the screw is under a compressive load (that is, the wedge lip is pressing against it) it should stay in place under recoil. Keep in mind that the wedge and wedge screw don't actually resist recoil; they tend to move with it, so the effect of recoil load is not as significant as it is on the recoil shield, for instance.

This works as long as the wedge is not worn and the spring in the wedge is still good. There is some evidence in Colt's drawings that they intended the screw to work that way. Unfortunately I think the wedge geometry and the spring stiffness don't retain the necessary relationship very long. In addition, the precision as to number of turns and fractions of turns is a bit more than most of us would be willing to practice while at the range. It's easier to just eyeball the cylinder end gap (once you know what the proper gap looks like) and push/pull the wedge based on that.