9mm: is crimping always necessary

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I have been reading this thread from the beginning and someone mentioned a Tap Test. Excuse my ignorance but what is a tap test? I have not heard that phrase before.
 
Once Again...Crimp DOES NOT HOLD THE BULLET ... Neck Tension does. TC is just to remove the flaring done to seat the bullet.
It holds it very nicely. Ever tried a lever action with bullets that are not crimped ? There's no neck tension in the world going to stop setback.
 
I make dummy rounds and chamber them multiple times in my 9mm's to test for setback. In my opinion, the crimp makes no difference until it is crimped so tight that it actually is compressing the bullet.

Neck tension or lack thereof is the greatest factor in reducing setback. I have had more problems with having a harder crimp *causing* setback by reducing neck tension in 9mm until I get to the point it is actually smashing/compressing the bullet in the case. I get the best balance by belling *just* enough to seat a plated bullet without shaving and then taper crimping *just* enough to remove the bell without deforming the bullet.
In lever guns? I have never seen a 9mm lever so I'll have to take your word for that one...I have loaded and shot .38 and .357 lever guns and , yes, roll crimping them is essential.

I'm no expert but test religiously - crimp does not reduce setback in 9mm in my shop. Neck tension is the fix and extra crimping can only wreck it.

YMMV.

VooDoo
 
Actually I have tested cartridges and dummy rounds with almost no crimp and none have ever set back (relying only on neck tension). If you seat a bullet with no crimp applied and press it against the edge of your bench as hard as you can, it should not set back any at all. If it does then your neck tension is too low and no amount or type of crimp is going to hold it in place until you solve the neck tension problem. I have to agree completely with Mr. Da Vinci. You must measure your expander plug and compare it to your chosen bullet dia. Many dies come with expander plugs that are oversized. I have had to turn down most of mine to get sufficient neck tension. The plug should measure 3 or 4 thous. under the bullet dia. Once you achieve good neck tension then crimp is only necessary to remove any flare your used so the cartridges will feed easily.
 
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It holds it very nicely. Ever tried a lever action with bullets that are not crimped ? There's no neck tension in the world going to stop setback.

Lever actions typically roll-crimp into a crimp groove, or actually cut a groove into the bullet itself which is ok because those actions headspace off of the rim.

We're talking about a taper crimp here for a cartridge headspacing off of the case mouth. Completely different animals. By the time you have a taper crimp that is actually going to hold anything any tighter you've created headspacing issues for yourself.
 
And neck tension aside, if a rimless cartridge is over crimped, the case mouth will not head space against the chamber throat. Now you have case mouths that may get pinched during discharge, and when this happens, pressures can go through the roof.

Over crimping can also create mis fires. This can happen because the mouth is tapered in too far, thus slipping past the chamber throat where it should head space. When the firing strikes the primer, the case can move forward, creating excessive head space, or deplete the necessary inertia to effect a deep enough FP indent.

Lets assume you have meticulously adjusted the crimp and bell, but you didn't trim the brass to matching lengths, which few reloaders do. Well now you have some that are over crimped, over belled, while some may have not been crimped or belled at all. As a result, neck tension will be all over the place, no consistency to speak of.

I don't load with anything but jacketed bullets, and I only load full tilt, with slow burning powders. If set back was a problem, I'm almost certain to have had a problem with my method of not belling or crimping rimless cartridges. The fact is, I've not had a single problem, with the only exception being brass that was too thin to provide adequate neck tension, which is an occurrence all reloaders encounter from time to time. I also bench test my loads by pressing the finished cartridge against the bench to check neck tension.

But what do I know, I've only been doing it this way for about 25 years, or since the .40 cal. came into production.

BTW, I don't bell any of my handgun cartridges, whether they are a rimmed revolver cartridge, or a rimless. An even chamfer of the mouth provides everything I need for a smooth and efficient operation, that produces consistent and maximum neck tension.

GS
 
It holds it very nicely. Ever tried a lever action with bullets that are not crimped ? There's no neck tension in the world going to stop setback.
Lever guns are normally rimed cases. Which is different on what we are discussing here. But yes, I have loaded for them and simi auto rifles (magazine feed). I do put a roll crimp if the bullet is designed for it. But most of the bullets I have loaded did not have the cannalure and I did not put a crimp on them. Did not have a problem and these were loaded near max, 308W. But it's std practice to roll crimp rimmed cases.

Back to TC....

With the elasticity of lead being different than brass, Any Crimp that deforms the lead core will loosen neck tension. This is why you only want to remove the flaring. This is easy to prove, and why it's not recommended to size a loaded round. Those using the LFCD normally have to remove the sizing ring if they are dealing with lead or over sized bullets. Even thick brass causes problems. I do not own a LFCD and do not plan on getting one. I've been reloading for near 40 yrs now and have not needed one. If you learn how to get proper neck tension you will never need one.
 
When dealing with straight wall or straight taper semi automatic pistol cartridges that headspace on the case mouth the less belling and crimping you do, the more securely your bullets will be held in place.

I've seen several statements in this thread that make no sense when applied to the above class of cartridges.

I only load +P and +P+ and if I do not crimp with a roll or FCD there will be bullet setback.

Seriously?
Talking about your affinity for roll crimping when you're posting in a thread about crimping 9mm Parabellum ammunition?
So what you're saying is that before the invention of the Lee handgun FCD the only functional automatic pistol loads were "wimpy loads that barely work the action".

And I always thought the 9mm Mauser and .44 Automag were pretty hot stuff. I guess I was wrong, you can't roll crimp 'em since they headspace on the case mouth and there were no FCD's back in the day so it would have been impossible to load 'em any hotter than a wimpy .38 Special wadcutter load.

Ever tried a lever action with bullets that are not crimped ? There's no neck tension in the world going to stop setback.

Again, what does this have to do with the question at hand? Is there a tube fed 9mm levergun that I'm unaware of? If so, how does it headspace after you roll crimp the heck out of your cases?
No one here is denying that a firm roll crimp into a cannalure can be desirable and effective IN CARTRIDGES THAT DON'T HEADSPACE ON THE CASE MOUTH.

For those that persist in thinking that a firm crimp is the only way to hold a bullet in place, I propose a simple experiment. Get a few Sinterfire frangible 9mm bullets and load 10 of them into cases that have been sized and then chamfered with no expanding or belling whatsoever. Do not apply any crimp to these loads. Then load 10 of the same bullets into cases that have been expanded and belled heavily (don't worry about overdoing it, if your theory is correct the crimp is what's important). Now crimp the bullets in place with a nice tight crimp.

After you crack several into chunks and dust you'll probably be able to get a few actually loaded by backing off on your crimp so that it just removes the belling, JUST LIKE EVERY RELOADING MANUAL I'VE EVER READ SAYS YOU SHOULD DO WITH CARTRIDGES THAT HEADSPACE ON THE CASE MOUTH.

Now take your two sets of catridges and test them by pushing the bullets firmly against a bathroom scale and record how much pressure it takes to set the bullets back in the case.

Congratulations! If you actually performed this test you now know that neck tension will do a lot more than crimping to hold a bullet securely IN CARTRIDGES THAT HEADSPACE ON THE CASEMOUTH. Which, after all, is what this thread is actually supposed to be about.

Another advantage of minimal or no belling is greatly increased brass life. The more you "work" brass, the harder it gets, and the harder it gets the more prone it is to splitting and cracking. So unless you're one of the .000001% of 9mm reloaders that regularly anneal their cases, less belling and crimping means you get to lose more brass rather than recycling it. :)
 
gamestalker - chamfer case

Quote from gamestalker
So after some thought, I chamfered the inside of my .40 brass mouths enough to allow a jacketed bullet to seat straight, and without shaving
I use an RCBS hand chamfer tool, so is
chamfer enough to allow bullet to seat straight
a trial & error thing till you get a good feel for needed amount of chamfer?
 
I use the same tool, but I have also used a Lee. Both were purchased more than 30 years ago, but I'm sure any of these will produce the same degree of chamfer.

There really isn't much to learn about how much to chamfer, nothing very technical here. Obviously, you don't want to chamfer to the extent that the mouth becomes a razor sharp edge, just enough to allow the bullet to set up on top so as to not fall over, or off, and it should set up nice and straight.

GS
 
@ jell-dog
In my experience, it can vary depending on what bullet you're seating. With the old Hornady 147 grain 9mm boattails all that was required was to remove any burrs or high spots that could scratch off flecks of the bullet jacket, seating the boattail did the rest.

On the other hand, unlike some others here, I've never been able to get away with not belling my cases when loading cast bullets. I've come close with some loads, but I'd still occasionally get that big smear of lead down the outside of a case that would hold up production and leave me with a 49 round box of ammo. :fire:

I HATE loading partial boxes of ammo! :cuss:
 
Maybe you all need to read more because my Speer Reloading Manual 11 manual specifically states

"All must be sized to hold bullets very tightly and the expander ball should not exceed .354 in diameter. Because this cartridge headspaces on the case mouth, very little crimp can be used. Test case neck tension by pushing the bullet of loaded rounds against the loading bench. If the bullet is easily moved deeper into the case, malfunctions may occur. But more important, loads that produced 28000 cup when bullets were purposely seated .030 deeper!"


Who are you that you think that you can argue against Speer when they state very little crimp?
 
Are you sure? The couple times Ive looked at crimps on factory rds, a few boxes appeared to have no crimp at all..and I wondered if they ever go without crimping. These had no trace of a crimp that my inexperienced eyes could see.. Maybe they're more perfectly executed and harder to see...?
If it was handgun ammo, it may be taper crimped not roll crimped, you will not see a taper crimp by eye.

If it was rifle, it is crimped much the same way as the Lee rifle crimper works, you can't see the crimp.
 
@swampman

If your 9mm round is subject to recoil impulse in the mag, it needs crimping. Neck tension will not hold it, whichever bathroom scale you choose to use.

I've noticed on this forum that the most argumentative replies to a post are by people that are experts in theory, and sometimes neither own nor use the items they offer their advice on.

I trust that you reload your own 9mm, at least 124 grain bullets to at least 1050 fps ? And if so, you never crimp and you never experience setback ?
 
@ jell-dog
In my experience, it can vary depending on what bullet you're seating. With the old Hornady 147 grain 9mm boattails all that was required was to remove any burrs or high spots that could scratch off flecks of the bullet jacket, seating the boattail did the rest.

On the other hand, unlike some others here, I've never been able to get away with not belling my cases when loading cast bullets. I've come close with some loads, but I'd still occasionally get that big smear of lead down the outside of a case that would hold up production and leave me with a 49 round box of ammo. :fire:

I HATE loading partial boxes of ammo! :cuss:
So you do apply a crimp.

You just call it removing the bell.

A better test for you is to resize your brass, do not bell the case at all [ so there is no bell to remove ], and load some copper jackets.

That will have no crimp at all, and you will experience setback.
 
The "crimp" for a 9MM is just removing the bell, or a hair more on the longer cases, but it is not for holding the bullets from moving. Neck tension does this. And yes, it is easily tested.
 
As far as set back, again, it would arrogant to state that I have never once experienced set back. Anyone who has been loading long enough has at one time or another experienced set back. But the only instances for me, considering I only load jacketed, was with thin or worn out brass, I don't load lead or standard plated bullets. I don't load anything that performs under 1050 fps in 9mm, the 1050 is with 147's I use from time to time, but I prefer the lighter bullets and the much higher maximum obtainable velocities with lots of slow burning powder, according to published guidelines, and work up results.

I located some published fact by Hornady that supports what the majority of us are stating, as follows and quoted by Hornady:
"Use little or no crimp when reloading the 9mm since it head spaces on the mouth of the case"

Lyman states the following:
" A modest taper crimp may be employed if found necessary "

My oh my, how did any of us ever survive without the LFCD before it was available! I've never owned it, and I don't intend to. And that isn't saying that it doesn't have a purpose, it just offers another approach to those who seek a different direction. I find it rather bold and excessively over stated to say it is essential, if that were so, the inception of the center fire cartridge would have been delayed for a good century.

It troubles me that this particular topic has evolved into a confusing and contradictory debate. We are here to answer questions for those who seek such assistance, not to strut our stuff, that solves nothing and only further alienates those needing accurate information.

GS
 
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Lee FCD

Did I miss someone mentioning the Lee Factory Crimp Die? It is ESSENTIAL!!!!
It cures almost all ills.
I used to have about 2 to 3 per cent failure rate (wouldn't go in a case gauge). Using range brass.
Seriously, get one of these and forget about it.
 
9mm: is crImping always necessary
Without complicating the thread discussion further, so far this is what I have:

- Yes, if you are flaring the cases. Taper crimp can mean returning flared case mouth back flat on the bullet or more which would indent the bullet and if used too much may cut through the plating on plated bullets

- No, if you are not flaring the cases as gamestalker illustrated by chamfering case mouth and using certain type bullets (rounded or bevel base)

- Neck tension comes from resizing case and not from taper crimp

- Lee Factory Crimp Die with carbide sizer ring can be used to apply taper crimp and fix out-of-spec finished rounds to chamber in minimum SAAMI spec barrels but many reloaders have been reloading successfully without the FCD

Did I miss anything?
 
Miss anything?

No, but your life will be simpler with the Lee FCD. I loaded successfully for a long time with a 2 to 3 per cent rejection rate. Due I believe to range brass from old glocks.
Yes it is possible to load without the Lee FCD. I have no quarrel with anyone who doesn't use one.
But a lot of this discussion will become moot if you use one.
 
I loaded successfully for a long time with a 2 to 3 per cent rejection rate.
I wouldn't call that successfully.

Part of reloading is not using brass that cannot be properly sized. The FCD cannot size tighter than a sizer down low, so it cannot "fix" a case that is bulged near the web. I also do not want to use a case where a "bulge buster" die is needed to squeeze it back down. If the case is swelled near the web, I consider it toast. YMMV of course. All the FCD can do is squish crooked bullets, wrinkles etc so they "fit". Just because the round "fits" now, doesn't make it better. IMHO of course. :)

bds covered the crimp part well.
 
And just the same, who are you to argue with Hornady or Lyman?

But also let me be honest and completely transparent as well, in that, Nosler and Sierra state that 9mm can sometimes require, or should have a firm taper crimp to prevent set back.

So where do we go with this now? It appears that some of the most trusted and published information from the manufacturer's is some how very contradictory as well. So who do we trust? Is it Lyman, Hornady, Sierra, Speer, or Nosler? I've long relied on my Speer #10 for technical information, so what's the story here.

I think at this point it safe to say that one should explore and use what produces the best and safest results for them. Even by referencing some of the most trusted manufacturing entities in the industry, we still end up back at square "A".

GS
 
While the FCD is a useful tool, many reloaders reload without one and I don't think this thread is about the virtues of the FCD for reloading 9mm.
 
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