Thread: 9mm reloads
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Old February 29, 2012, 12:29 AM   #12
scsov509
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Join Date: November 22, 2006
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Quote:
I've only edited this like 10 times. Watch this [youtube.com] . I can't seem to find the exact video. I shouldn't try explain this in case I can't remember exactly, but after seating a dummy round you should be able to drop the bullet in and it should fall right back out of the chamber. You shouldn't have to pull it out of the chamber. Also make sure the case length is within spec.
I think you're confusing measuring headspace with OAL, which are not the same thing. Headspace is the chamber stopping the forward motion of the case in the chamber and properly positioning the case head relative to the bolt face. Proper headspace on a straight wall pistol case like the 9mm is determined by the mouth of the case being positioned in the chamber properly, and not the bullet engaging the lands. On rifle rounds that headspace on the case shoulder in the chamber, it's typically possible to seat the bullet out far enough to engage the lands and actually effect your headspace by not allowing the shoulder to get forward far enough in the chamber. But on something like a 9mm pistol, it is pretty unlikely that you'd actually be able to set the bullet out far enough to engage the lands as your describing and still fit the completed round in the magazine.

So if you're having problems with the rounds seating properly, especially at the OAL's you're describing, it's not likely at all that the problem is the bullet engaging the lands. Rather, it's most likely a problem of the case not headspacing properly in the chamber. And I'd suspect that, if you're having headspacing problems, it's probably related to crimp rather than OAL. Too little crimp and you won't headspace correctly because you're not getting the case flare out of the case. Too much crimp and the mouth doesn't headspace properly because the case moves too far forward in the chamber. I'd be willing to bet your problem is there, and highly doubt it's related to OAL.

What I'd recommend you do is make some dummy rounds at a longer OAL, whatever is recommended in the manuals you're using for the bullet weight you choose. Then play with a minimal amount of crimp on the bullet an increase it as needed until you're getting proper headspace. Make sure also that you're not putting too much flare in the case to begin with, only as much as is needed to start the bullet in the case. Then like I said, you gradually increase the crimp until it removes the flare and allows the case to drop in and out of the chamber freely and properly headspace. I think if you do that you'll find that the OAL you're describing is much shorter than you need.
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