Bullet Creep: Federal 9mm Luger 115grain FMJ - no powder in cartridge

[92G]

No data, just pass/fail through his own BS test? Interesting stuff but wish he was a bit more scientific. Unless people are carrying 12-16 shot revolvers then his test isn't very helpful.

??
he is providing data on bullet jump under recoil. i would say it's useful data. how would he be more scientific? suppose he could publish the exact changes in OAL under recoil but personally i'm fine with him just stating which ones jump crimp and which dont.

 

[ILikeGlocks]

Interesting. My wife had a squib with 115gr Blazer Brass a month or so ago. unfortunately, we were unable to find the casing to attempt any additional forensics.

 

[Shmella]

In 9mm The crimp doesn't hold the bullet in place. A properly size case holds the bullet "neck Tension" is the term ive heard it called before. More crimp will certainly bite the bullet but that isnt the proper way to hold a 9mm bullet in place. Ive heard of this same thing, bullet jump, in revolvers and a lot of ppl recommend more crimp. That might be helpful information for 38 special, I dont really know but in 9mm a stronger hold on the bullet Ie. more neck tension, undersizing the case, Should do the trick and not have the ill effects of over crimping.

 

[wiryone1]

This whole thing kind of gets back to why we have revolver cartridges that headspace off the rim of the case and have a heavy roll crimp, and conversely semi-auto cartridges that head space off the case mouth and hold the bullet with neck tension. In addition to that, most rimmed revolver cartridges have some sort of crimp groove that the mouth of the brass can be rolled into, hence the roll crimp. This whole on and off history of manufactures building revolvers in semi-auto calibers while handy and practical in many respects, is going to be prone to problems, especially in something small and light.

 

[The_Raven]

So is there enough of a market to justify an ammo manufacturer to make a 9mm Luger cartridge with the enhanced crimping necessary to prevent this? Or are revolvers in semi-auto sizes too rare to bother with?