Bullet Migration in 9mm Revolvers by John Farnam
| 4 Apr 2017
“Bullet-jump” with light-weight revolvers, particularly those chambered for 9mm:I don't have contact information for Mr. Farnam (a well-respected trainer in these parts), but if you have a 9mm revolver, you may want to be aware of his warning.
Last weekend, during a Defensive Handgun Course, a student brought a Ruger five-shot revolver, chambered in 9mm.
During an exercise, shooting factory 115gr hardball from a well-known and reputable manufacturer, a bullet jumped forward far enough to protrude from the face of the cylinder and thus prevent the cylinder from rotating normally. In fact, the bullet jumped forward far enough to physically separate from the case. This not only precluded the revolver from continuing to fire, but it also made it impossible to swing-out the cylinder, so the revolver could now not be reloaded!
Revolvers are often held to be "the most reliable handgun in the world" by some people, but I have had personal experience of "loose gripped bullets" in revolvers causing this cylinder lock-up.
In fact, while officiating at IPSC matches (over the past 30 years), I've actually seen at least one example.
This was, in fact a .38 Special revolver (I do not recall the manufacturer of the pistol or the ammunition), but it stopped cold the budding career of a wanna-be Revolver Ace.
This young man was a member of a group of revolver afficianados who came to a Major IPSC match in Oregon to prove that Revolver Shooters ... uh .... I'm not sure what he wanted to prove. But he had a cartridge which was not sufficiently crimped (as I recall, he was using handloads with cannelured lead bullets) and he had failed to sufficiently crimp one round.
He fired over 500 rounds in a 600 round Crocodile Dundee High Round-Count Match, and he had his wife and his two (3?) Children reloading his speed-loaders for him.
I'm not sure, but I think he even brought his cat with him!
I had squaded with him, and I was
(His family was close to weeping for "Daddy's Misfortune".)
They came from the Shasta, California are, and my friend if you are reading this I hope you are encouraged in knowing that you are not the only revolver shooter who has ever experienced this kind of 'failure' in a high-profile situation.
I suspect that having your revolver lock up during a John Farnam Class is at least as embarrassing as during a Crocodile Dundee Crazy Croc High Round Count / Weekend In Hell match.
https://www.youtube.com/watch?v=Fr7rrjmcZ9s
4 comments:
Was our esteemed scribe shown dashing though one of those stages?
I shot at least 2 Crazy Crocs with a 6 shot revolver (S&W 625). Had
exactly the same malfunction. Somehow a piece of AMERC 45 brass got
past inspection, bullet popped out and tied up cylinder. Pushed it back in with finger far enough to get cylinder open. Not fun.
If you are going to shoot 9mm. from a revolver, the ammo MUST BE CRIMPED to prevent bullet jump. Or buy 9mm. ammo specifically for a revolver.
9mm. Ammo is headspaced on the chamber at the neck and does not need a crimp for a semi auto pistol.
The problem is not the crimp (or lack of). It is because the brass was over expanded. A crimp is not sufficient to hold a bullet in place against setback from feeding in a semi auto or pulling from a revolver. Case neck tension is what secures the bullet in place. Factory ammo today is mass produced and sloppily made and no manufacturer guarantees their ammunition to be in spec. and to not pull or setback. If you want properly constructed ammunition you MUST make it yourself.
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