View Full Version : Extractor tuning
28th June 2004, 23:30
The extractor on a custom built target gun using various parts has been leaving the fired case in the chamber about once every magazine or so. Since this is a target gun and not a defensive gun it is just an annoyance. Also since it my life doesn't rely on it I would like to fix it myself. How does a relatively unskilled person such as myself tune(bend) the extractor to get more positive extraction. If I screw it up it will have to go to the gunsmith anyway so I may as well give it a try. Thanks in advance everyone.
29th June 2004, 07:29
One way would be to remove the extractor from its tunnel, reverse it so the claw or hook end is sticking out of the tunnel about 1/2 way and then gently bend it so there is a little more bow in the center with the head and hook side being the ends of the bow. There are a couple of tools that you could buy to tune the extractor, most of which support the extractor on both ends, with the open end of the claw or hook facing up, and use a screw to put pressure on the unsupported center causing it to bend.
just go slow and try the tension as you go. You want enough tension on the case to hold a loaded cartridge against the breech face with just the hook pressure. Enouth pressure to hold it but at the same time not so much pressure that the cartridge can't move.
29th June 2004, 08:00
An extractor that leaves a fired case in the chamber may have other issues besides lack of tension. Many 1911s will function surprisingly well without an extractor, and even those that don't will usually get the brass out of the chamber if the extractor is in the gun, regardless of tension. It may cause
stovepipe failures to eject, or erratic ejection...but the case will exit the chamber in most cases.
Assuming that the extractor isn't soft or out of spec:
It may be something as simple as a worn hook, an out of spec (tight) chamber, or heavy fouling...or it could be as complicated as unlock timing of the barrel or a rough or tool-marked chamber.
If the barrel unlocks too early, while chamber pressure is high enough for the case to be expanded against the chamber walls, the hook can slip over the rim. Indication of the condition will generally be a damaged point on the rim that matches the size and shape of the extractor. This particular malfunction may not show up unless the extractor hook is worn or the tension is low. If the condition exists, it will accelerate hook wear or loss of tension.
Other indications of early unlock timing may be a tadpole tail mark on the primer or flattened primers with shear marks. These two signs may also be indication of a weak firing pin spring, and is not an absolute indication of
a timing problem. Neither is the lack of them an absolute indication that the
timing is correct.
Note also that the failure to extract can be caused by a powder burn rate
that is too slow for the application. The chamber pressure peaks more slowly and holds the peak for a longer time, which may be too long for the chamber
pressure to fall to a point that will allow extraction.
A stiffer recoil spring will not delay the unlock timing of the barrel, but a stronger mainspring will have some effect by delaying the slide's rearward movement. A firing pin stop with a smaller bottom radius will also work to
delay the slide for a fraction of a second, possibly giving the chamber pressure
time to drop and allow the case to extract.
Note that Springfield's OEM extractors have been showing up with problems
recently. Improper heat treatment causes premature wear and the inability
to hold tension.
vBulletin v3.0.13, Copyright ©2000-2013, Jelsoft Enterprises Ltd.