My dad bought out a Colt 357 trooper with some problems: these are I frames, identical to pythons on the inside. This is a short writeup on fixing the problems (for the most part). Note there's no sexy action work here, just a few fairly typical problems and one weird one. I write this stuff up so I don't forget, but no guarantees about riveting narratives.
The first problem: the cylinder does not spring back when you push it:
Removing the ejector and assembly the issue is obvious: the ejector spring actually slips underneath the ratchet bushing. The rectangle shows where the bushing is (screwed into the crane), its goal in life is to hold the spring back, and it's not meeting much success:
If you look at the head of the spring, it's messed up compared to these stock springs, one old style, one new:
As A1A notes (and the Kuhnhausen manual discusses) the end has to bent correctly or it will escape the bushing. I messed with the end but could not improve the result. I went tried numerous NOS ejector springs (new and old style) and none worked any better than what was in there.
Looking closer though, the ejector rod seemed thinner than normal. After measuring with calipers there was a non-trivial difference between various python ejector rods and what was in there. (I can't recall the number now unfortunately and dad took the gun with him so I can't check again.) If the rod is too thin the spring will just slip by. Fortunately I have a bunch of spare rods. Swapping a new one in fixes the problem. Nice. One of the few colt replacements where you don't have to fit anything. Much. Rejoicing.
Weird situation though. It's not like the ejector rod is a high wear part.
The next problem is that the bolt falls off the side of the rebound lever. This isn't a good photo, but you can kind of barely make out the tail of the bolt falling off the side of the rebound:
This makes the bolt drop funny, and often leads to a more pronounced "click" when the bolt pops back up.
The cause of the problem is what it usually is: The cam (in rectangle) slopes (red rectangle) rather than coming out at a right angle. Easy way to see the problem: compare the rebound in the gun (red rectangle) to a stock one (black):
We fix this by using a file to put it back the way it should. Removing metal from the rebound cam has to be done extremely carefully --- remove too much material and the bolt won't be able to touch this cam, so you won't be able to get instant bolt pickup and the cylinder will catch.
There were some other problems, but I'll only note one since "fixing" it can easily lead to frame damage if you do it incorrectly.
If you push the bolt up and down on this colt it moves back and forth too easily. It should move with slight resistance. The recommended fix is to counter-bore the frame (i.e., cut a circular chunk from it) so that the bolt screw can screw in farther, thereby pressing the bolt against the frame harder.
Of course, what isn't usually mentioned when discussing this counter-boring fix is that there is another possibility --- that the bolt is too thin. (An easy thing to happen if someone filed it too far --- they either leave it or replace the bolt, which is time consuming and expensive. Guess what they usually do...)
If the bolt is too thin and you counter-bore you've just done essentially irreparable damage to the frame (can't put that metal back). The bolt screw will stick out too far, people will laugh. In this case, what I've been told you can do is to cut the bolt screw down with a lathe, making sure to not damage the threads. A different, neat alternative if you have the right tap: drill and tap a hole into some thin metal, screw in the screw, grind it down to the length you want and then unscrew it. Unscrewing will "fix" the end of the threads. Not my trick, but I think it's pretty damn cute.
So, what do you do if the bolt is too thin? Replace it! But, I didn't have time (dad leaving), so cheated. The only symptom I was seeing with the bolt was that it was dropping too soon. Other than that it wasn't behaving erratically. So, since we were going to replace the bolt spring with a lighter one as part of an action job(*) we do so now to see if that fixes the timing issue. It does. So we declare victory after doing a boatload of dry firing to make sure the bolt behaves right.
Now, of course, replacing springs with weaker ones to "fix" problems is generally pretty stupid. I only do so in this specific case since (again): (1) the only symptom was a delayed bolt drop and (2) we were going to swap springs anyway. But, in general, have your dad stay longer and replace the bolt! Fixing problems by swapping springs is almost always a sure sign of a hack that will fuck up your pistol.
(*) Colt will actually file the spring thinner, but replacing is easier.
And there you have it. Next post will be on tuning the action.
No comments:
Post a Comment