"Epic revolver failure." Really? You sure about that?

Wednesday, April 22, 2009 Filed in: Revolvers, Gunsmithing
Someone sent me a link to this video yesterday:

The crane worked its way out of the frame, taking the cylinder with it. (You can hear the distinctive ring of the crane hitting the ground at 1:04.)

The submitter of the video - who is also the shooter - calls it a "defect", but is careful not to identify just what the defect might be. He then goes over to ar15.com, where he posts the cause as "shitty metal" and says that some gunsmith claims to have seen several with identical failures. (I should note that I have yet to see even one such failure.) He also says that the crane retention screw was still in the gun.

Some background: the crane, which is the piece on which the cylinder rotates, is held in place with a screw. (Those of you with S&W revolvers can look at the right side of the gun, and the screw that sits just above the forward attachment point of the trigger guard is the crane retention screw.) On newer guns it contains a spring-loaded plunger which holds the crane, on older models it was simply a slightly longer screw.

Since he claims this to be a "newer" gun, it's no doubt of the spring-plunger variety. (As an aside, note that the other participants in the thread seemed surprised by this, to their minds, "recent" change. Apparently none of them are aware that the spring plunger was adopted clear back in 1986, no doubt before some of them had even been born!)

Back to the topic at hand...if that screw works sufficiently loose, it will give the crane enough clearance to slide out, but the screw will remain in the frame. On quick glance, is may even appear to be properly installed. If the screw is out just the right amount, the crane will be just barely retained, but will separate with a little forward pressure - during a speed reload, for instance. Under those conditions the tip of the plunger and the mating surface on the crane can both be slightly damaged, leading the inexperienced to conclude that they were defective in some manner.

So, faulty gun - or something else?

In the forum post, the shooter tells us he changed the mainspring, but insists he didn't remove the sideplate. Now understand that I do that task on a very regular basis, and even I remove the sideplate to chainge the mainspring - it's a serious hassle to do otherwise, especially with the new (post-lock) guns. Once finished, it' easy to replace the sideplate but neglect to fully tighten the screw. (It's even easier to forget to check that screw every so often, even if one hasn't messed with it!)

Remember that I don't have the gun in hand to inspect, and I'm willing to give the fellow the benefit of the doubt, but I have not heard of, nor seen, any crane retention failures caused by "shitty metal." I have, however, seen lots of them from failure to tighten the retention screw.

If you remove screws from your revolver, be sure you do two things: first, make sure you put them back in their proper holes (they are different), and make sure they're very tight. A dab of low-yield LocTite ('purple', type 222) will ensure that they stay in place but won't hinder their removal.

Even if you don't remove them, it's a good idea to check them occasionally. It's part of normal revolver maintenance and the responsibility of the informed user.

-=[ Grant ]=-

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