Differences in 9mm ammunition Added a Picture

I admit I do scrounge for brass while at the range. When I find calibers I don't reload for, they go into a recycle bucket and at a dollar something per pound, it's worth it. But I reuse the 9mm I find. I have the wet tumble cleaner with steel pins, and that old brass looks brand new when cleaned.

However, I was shooting 9mm yesterday and a few cases wouldn't chamber. It was as if they didn't get resized. I'm shooting 124 grain bullets from Missouri Bullet Company. Their "Small Ball" coated ammunition. It's pretty consistent and nice stuff, so the brass would have been the only variance...I think.

QUESTION: Could my problem have come from variances in different brands of brass? I made a mistake of not noticing if the 6 or 7 bullets which wouldn't chamber were all one brand or not. I threw them away and didn't think about this problem until last night. I don't think it was all one head stamp however.

I wondered if I had the problem Mobuck had about the bulging from a heavier bullet. Perhaps the cases were to thin and didn't hold their shape when seating a heavier bullet.

And then I found this 9mm case. a Black Hills Ammunition 9mm+P Proof. I don't believe I've run across this head stamp before. But, as noted above, I don't check all the cases.

I guess this is my proof all brass isn't the same. I had this trouble with 38's a while back.

It's interesting though, this is marked proof. I haven't ever seen that on any caliber.

I use a Lyman ammo checker, I don't check every one but check often when reloading.
https://www.midwayusa.com/product/1016393015?pid=464540

Hey thanks! I just ordered one.

How are you crimping the case mouths and how are you determining how much to crimp them?

Cholo said:

How are you crimping the case mouths and how are you determining how much to crimp them?

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Good post Cholo. I'll add a tidbit; I do not crimp my semi auto rounds (32 ACP, 380 Auto, 9mm or 45 ACP). I just remove the flare and check with the plunk test. Early in my semi-auto reloading ('88) is thought I needed to check in a case gauge and measure the crimps. I soon learned all that was not necessary and just began plunk testing (I was firing my handloads out of my guns, not a gauge)...

Crimp is with a separate crimp die. How much? Not a lot, but probably more than necessary. I read somewhere 9mm isn't supposed to be crimped at all, since it headspaces off the case mouth.

But I've read elsewhere, semi auto calibers need more crimp than a revolver caliber.

I'm finding less and less correct information on the internet. Unrelated to guns, I had a printer I messed up pretty bad from some completely wrong information on the internet. I followed the "directions" and ended up having to spend $75 on a new part because the directions were wrong.

The crimp is the problem in my opinion, and the amount can't always be guessed at. Measure the case mouth of a quality factory 9mm cartridge with quality calipers. Speer or Federal are good ones. Get the measurement and then measure your case mouths. I'll bet that they're .001-.003 too large. Adjust your taper crimp die to equal the factory case mouths. I wouldn't go by what any gun writer says, the factory knows better.

Yes, some brass is thicker/thinner than other brass, but was fired in someone's gun, right? It's not working in yours. It seems to be a case of operator error. Now how could I possibly know this? Yup, my 1st ever 40 S&W reloads wouldn't go into battery in my tight chambered Kahr K40 about 24 years ago. I measured a factory case mouth and mine were .001-.002 larger. It made all the difference in the world

PS: Spend the $ on good case gauges. I have Dillon for .40 and .45 ACP. They've never lied!

On 9mm and 45ACP I taper crimp. I never have any problems.

A bad crimp could be the problem, but Range brass is very likely the problem. Not that there's anything wrong with most of it, but it has to be sorted. Some will have been loaded too hot for some brands of pistols, Glocks for one & there will be a bulge close to the base. I think if you have a real good look at the ones that don't chamber you'll see what I'm explaining.

If I only shot a Glock or other semis with a generous throat I might not have noticed, but my 1911 in 9 refuses to chamber some. I take the barrel out of it & use it for a gauge. If the shell plunks into the chamber all the way it goes in the 1911 ammo bin, if not, it goes in the Glock ammo bin.

Adjusting the sizing die very close to the shell holder can help, but is not usually the solution. Redding makes a push thru sizing die called the G-Rx, that solves the problem.

Edit: the base bulge I refer to is most common with 40 S&W cases. Further research indicates than 9 mm cases are not usually affected by Glocks, but rather by very hot loads in anything, particularly major power factor 9mm race guns. Redding doesn't seem to make a base sizer in 9. Some are using a form of a Lee die for this.
Seems sorting & trashing the bad might be the best bet.

Thank you all for the replies. This is some good information to act on to solve the issue. Today is especially cold here, so I'm not going to do any reloading today, but later this week, I'll get into the garage and see if I can load some good stuff.

I think it's a combination of the solutions above. I did load 50 rounds as a trial to see if the powder amount was correct and if they would fire. From the Hornday AP Press. The first box of 50 all fired without issue, and in fact were actually really accurate. It was the next box of 50 I had the trouble with, and then only just a few rounds out of the box.

I actually kind of like problems of this sort. They make me stop and analyze the reloading process in detail. Plus all the great advice here is extreamly helpful. Thank you again.

gunzo said:

If I only shot a Glock or other semis with a generous throat I might not have noticed, but my 1911 in 9 refuses to chamber some. I take the barrel out of it & use it for a gauge. If the shell plunks into the chamber all the way it goes in the 1911 ammo bin, if not, it goes in the Glock ammo bin.

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Odd, my buddy's G19 is very picky about ammo. When he and I were developing 9mm loads he had a lot of ammo that his 19 wouldn't chamber. My SR9c would eat them and ask for more. I've also heard other owners say their Glocks were picky about ammo.

CH,
Just goes to show you, each & every gun has it's own personal dimensions. While most Glock chambers are said to be on the plus side(attributing to their willingness to function well), some may be a bit tighter.

I had a very early 19, & from my experience since, the early one was a bit tight. But then again.......... my knowledge of loading for semi-auto pistol cartridges has progressed considerably.

But I've read elsewhere, semi auto calibers need more crimp than a revolver caliber.

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No! Total hog wash. The design of semi-auto, rimless cartridges dictates a light taper crimp to allow head spacing. Actually, just enough to allow a good "plunk"...

Be careful where you get your info, as newer reloaders haven't developed their "BS filter" enough to spot junk like that. If in doubt refer to your reloading manuals or texts...

In the future, don't toss those faulty rounds. You need them to determine the problem.
Since you referred to my issue, I'll relate that the problem(s) I had were VERY noticeable in the finished ammo. You would have noticed those while loading your magazines.
Also keep in mind that generally speaking, the crimp on revolver rounds is to prevent bullets "pulling" (moving forward) while the primary need for crimping semiauto ammo is to prevent pushing the bullet into the case during feeding. Obviously quite different requirements. One way to lessen the need for crimping 9mm more than just to remove the flare is to use a powder that ensures the powder space is full. Example: using something like TiteGroup may leave air space between bullet and powder making "setback" a possibility while something like AA#7 fills the case to firm contact with the bullet's base which will make "setback" more difficult/impossible..

Kevin said:

Crimp is with a separate crimp die. How much? Not a lot, but probably more than necessary. I read somewhere 9mm isn't supposed to be crimped at all, since it headspaces off the case mouth.

But I've read elsewhere, semi auto calibers need more crimp than a revolver caliber.

I'm finding less and less correct information on the internet. Unrelated to guns, I had a printer I messed up pretty bad from some completely wrong information on the internet. I followed the "directions" and ended up having to spend $75 on a new part because the directions were wrong.

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Kevin I don't know where you read, 9MM 'isn't supposed to be crimped' ALL Semi Auto should be crimped to prevent BULLET SET BACK, when the round hits the feed ramp, going into the chamber. If a set back occurs ( which will increases pressures)especially with the 9MM/38 Super/40 S&W. Thus if the SET BACK is serve the gun could let go, resulting in injury to you and other shooters.

Ok, a lot of good info above.

I see a LOT of 9mm ammo used at my monthly matches at my range. It's the most popular caliber now in USPSA.
MOST shooters use reloads.
MOST shooters use a progressive reloading press.
MOST shooters have an issue or two occasionally.
MOST shooters who do NOT have issues do a few things the same. They first sort the brass by brand. They also use either a push through die to resize,, or the use a roll sizer die to uniform the brass. Especially when using range p/u brass. Next,, they use a taper crimp to final crimp the brass to the bullet. Lastly, they also use a chamber check gauge to check their ammo before shooting a match.
And lastly,, they all are aware of the sensitivity of the depth of the seating of the bullet in a 9mm case that changes the pressure.
Competition shooters usually shoot thousands of rounds annually,, and if there are going to be problems,, they will find them. Study their methods and you will find the patterns of quality ammo & how it is assembled.

FWIW; "crimping", as in squeezing the case around the bullet, is not needed on a semi-auto round. Neck tension holds the bullet in place. I have 9 semi-autos and tens of thousands of rounds through them, often with mixed range brass, and none need to have a crimp to keep the bullet in place (32 Auto-45 ACP). One major problem with newer reloader is over crimping semi-auto handloads and quite often, loosening the neck tension and/or bulging the case...

Kevin also keep in mind that ALL factory semi Auto ammunition is crimped, let that be your guide

Again, thank you to all for the thoughts on how to best reload 9mm. I appreciate it, and slowly it's making me better at reloading.

Well, I had time to do some reloading this weekend and went very slowly to see the amount of crimp etc.

Then I started to notice my bullets. A couple weeks ago, I ordered some new 124 grain bullets from Missouri Bullet Company and they are slightly different than the last batch from another company. Then I really started to pay attention. The "old" bullets averaged .358, while the new bullets, are closer to .356. The other bullets have that additional band (circled in green in the picture) while the "new" bullets don't. Plus, the other bullets were indeed bulging the case just every so slightly when I was crimping. The other bullets were sold as .356 and 124 grain, however, they are slightly heavier as well, averaging around 127 grain. I think I'll stick with Missouri Bullet Company from now on. Besides, they have extremely fast shipping.

It is just an average, some were .357 and some .358 and some at the .356 they are supposed to be. This showed up when I was at the range...those wider bullets caused the troubles.

Thanks again for all the help!!!