Help with 9mm Headspace

[35remington]

Mike, you're not paying attention. And I'm not beholden to the gun mags, just correcting the mistaken impressions advanced here. "The extractor not headspacing" comments I have are when the right cartridge is used in the right gun.

I didn't say that the WRONG cartridge COULDN'T headspace on the extractor, as in 40 in 45, 9 in 40, etc, etc, as it can and does, as the visible proof shows of bulged cases.

Where you err is in assuming that the extractor headspaces the majority of the time when the correct cartridge (45 in 45, 9mm in 9mm) is fired in the correct chamber. It does not, clearly and demonstrably the vast majority of the time.

It can, and does, headspace on the case mouth the vast majority of the time when fired in the right chamber. (Or on the bullet if it contacts the leade). But not on the extractor.

"you can claim all you want, those of us that actually custom build guns and ammo, know otherwise."

Building a custom gun doesn't automatically make you a headspace expert, as Charles Petty built custom guns too and also got the "headspace on the extractor" thing wrong.
It's time to look at the right information regarding autoloading pistol cartridge headspace in the proper chamber.

Mike, the extractor does not headspace the round when the right cartridge is used in the right gun. The vast majority of the time. It is important that you understand the distinction, as you're comparing apples and oranges when talking about headspacing a 40 in a 45 by the extractor, or a 9mm in a 9X21. I don't understand why you're making this irrelevant point. It isn't germane to this discussion, as we're talking about using the right ammo in the right chamber.

[StarMetal]

35remington is right. Another thing that throws some people off is that the firing pin on the 1911 can have a long travel. One thing not mentioned is often, especially with lead/cast loads, the bullet shoulder headspaces the round. Not exactly the correct thing to do, but lots of reloaders do it.

Another thing brought to my attention about the 1911 is the firing pin stop. If you look at the current ones the bottom edge is rounded to easy camming the hammer back. I was told that this isn't the correct profile. See the weight of the slide, the recoil spring, and mainspring are what control the slide recoiling. I was total that the original firing pin stop had a less round profile and the reason being that it would require more effort to cam the hammer back which was all figured in the total scheme of 1911 slide control. Any comments here about this?

Joe

[fecmech]

There was a discussion on The High Road back some time ago on that subject. Early Bullseye "smiths" changed the profile on the stop to better handle the light loads used in Bullseye competition. Some pretty knowledgeable fellows over there on the .45 auto. JMB had it all figured into the equation, the stop profile, mainspring weight and recoil spring weight. They all have an effect, it's not just change the recoil spring.

[leftiye]

Youse guys sure can find thangs to argue about! What I don't see is why it isn't just left at "for each of these scenarios, bett your butte that there's a gun out there that functions in that way." Further, as has been stated, it would be sheer folly to consider that any but a very few guns were made precisely as they should be made. What should be has been outlined in several angles, what is - is what you've got to make your ammo fit. Therefore, if it will chamber, a cartridge assembled so that the boolit touches the rifling is the end-all of this discussion.

[UncleClark]

If your completed rounds do not drop completely into the case guage is could be that you need to apply a bit more taper crimp. I have had that problem with 45ACP and 9mm is similar.

You 'belled' the case mouth before you seated the bullet and unless you undo the bell it might not drop completely into the guage. I use those Dillon guages a lot and have found them quite usefull in helping to adjust the crimp.

Also make sure your guage is cleaned out - they can load up with gunk.

Hope this helps.

[tding]

Loaded 50 9mm's last night sized to .356. 47 out of 50 dropped right into the gage. The difference was using two seperate steps (seating then crimping) instead of trying to seat and crimp in one step. It appears that the boolet was being crimped in the one step process.

Still wish I understood the process better. Even tightening the crimp on the last 3 boolets they will not drop completely into the gage.

[dwtim]

I hate to impose, but it is possible to post a zoom pic of the cartridge that won't fit in the chamber gauge, and perhaps one inside of your calipers?

The problem I had with one-step seat and crimp in the 9x19 was lead shaving. The seat body on my RCBS die is pretty wide, so now I flare the case mouth slightly before seating. It works out because I always taper crimp my nines. (Well, okay, it is a problem because the case mouth work-hardens, but that takes a while.)

[MtGun44]

Are you taper crimping, or using a roll crimp?

In 45ACP tc is critical to proper cartridge fit in the chamber. I tc
my 9mms too, but have loaded FAR,FAR less 9mm than 45 ACP, and always
have tc'ed my 9mm, so not as sure about tc vs roll for the 9mm, but I would
recommend it as a general rule for all semi-auto pistol rounds.

I did load a whole lot of .38 super and it required a tc for reliable chamber fit.

Bill

[StarMetal]

Are you taper crimping, or using a roll crimp?

In 45ACP tc is critical to proper cartridge fit in the chamber. I tc
my 9mms too, but have loaded FAR,FAR less 9mm than 45 ACP, and always
have tc'ed my 9mm, so not as sure about tc vs roll for the 9mm, but I would
recommend it as a general rule for all semi-auto pistol rounds.

I did load a whole lot of .38 super and it required a tc for reliable chamber fit.

Bill

I tc nothing and have zero problems. I build a match upper in 9mm for my Gold Cup frame, as I mentioned before, and the match barrel has a very minimum chamber. First one I've ever had to trim my brass to fit. It would chamber any bullets larger then .354 I don't, yet it chambers perfect and without tc the rounds. All my tuned 45's also chamber perfet without a tc. In fact they chamber empties which you know aren't tc'ed.

I don't know, seems some people have to tc, but I never have. I sure would like to try your pistols sometimes...bet I can get them to chamber reliably without a tc.

Joe

[tding]

With apologies for the photography

[UncleClark]

It might be the diameter of that first band on the bullet that is showing. Is there any difference in diameter at that first band? Either that or the taper crimp. It looks like the round is not dropping in by about the height of that first band.

[dwtim]

Ah, thanks for the picture. Now I understand why you're sizing down the bullets. There is a noticeable stretching of the neck in the right hand example. How thick are those case walls?