Crimping 9mm Not Required?

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CQB45ACP

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Picture shows my latest batch of 9mm cartridges not requiring ANY crimp at all to drop freely into gauge. (And, yes, if a round passes this particular gauge it will plunk in my particular pistol).

As a test, this batch comprises four FC cases and three each Blazer and PMC. All have Extreme bullet as shown.

Half were seated w/Lee seater (adjusted without crimp) and the other half w/Redding Competition (has NO integral crimp capability).

I do push test each round for tension.

So, I must’ve found the sweetest sweet spot on my Lee expander and dare not touch it ever again nor ever use a different bullet.

I used to frequently get several individual rounds per batch of ten not requiring a crimp but this 100% result is now common and it bugs me to accept it simply as good luck but I can’t point to anything I’ve done to earn it.

IMG_4197.jpeg
 
Me, I would crimp anyway. I do not have much experience with 9 mm. Is there an advantage to not crimping? I load mostly plated bullets so I may flare more than you do?
 
Charlie98 said:
I would work up 5 dummy rounds and drop the slide on them. A slow push on the nose of the bullet is one thing, the whack of the feedramp and chamber is quite another.
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Thanks. I’ve shot at least a couple hundred rounds, they’re fine. But crimping doesn’t change tension except make it worse—well doesn’t improve it.
 
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Bill M. said:
Me, I would crimp anyway. I do not have much experience with 9 mm. Is there an advantage to not crimping? I load mostly plated bullets so I may flare more than you do?
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These are plated bullets.

I don’t know about advantage of crimping one way or the other but if it’s not necessary???? Guess I’ll hear about it.
 
CQB45ACP said:
Thanks. I’ve shot at least a couple hundred rounds, they’re fine. But crimping does change tension except make it worse
Click to expand...

My concern isn't whether or not they were fine shooting... my concern is bullet setback on chambering. I'm probably a little overcautious with the 9mm, Back Home, Years Ago, I nearly got into trouble hot-rodding the 9mm... and much of that had to do with my crimp and COL.

It does, however, seem like you have found the sweet spot on your flare, and that's even considering you are loading plated bullets... :thumbup:
 
Charlie98 said:
My concern isn't whether or not they were fine shooting... my concern is bullet setback on chambering. I'm probably a little overcautious with the 9mm, Back Home, Years Ago, I nearly got into trouble hot-rodding the 9mm... and much of that had to do with my crimp and COL.

It does, however, seem like you have found the sweet spot on your flare, and that's even considering you are loading plated bullets... :thumbup:
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Got it thanks. I guess it boils down to what a taper crimp does and doesn’t do. Or can and cannot do.
 
9mm, 40S&W, 45 ACP I rarely crimp. I set me crimp die just to remove the case flare from the powder drop station and maybe .001-.004 less than the nominal case mouth diameter. Never had an issue with bullet moving either way and I shot a lot of my 40S&W and 45 ACP reloads in both semi-autos and revolvers.
 
"so do you feel lucky? Well do ya"

Eventually you will get a case with not enough neck tension and have a set back resulting in a squib or a Kboom. There is no advantage to not doing a taper crimp.
Just because a round will plunk in a barrel or gauge means diddly as to how well the bullet is secure in the case.

Lots of thread here on set back. Many on chambering factory rounds after clearing a gun. As mentioned above, measure your COL, then rack them through the gun letting the slide slam, measure the COL again.
 
Rule3 said:
"so do you feel lucky? Well do ya"

Eventually you will get a case with not enough neck tension and have a set back resulting in a squib or a Kboom. There is no advantage to not doing a taper crimp.
Just because a round will plunk in a barrel or gauge means diddly as to how well the bullet is secure in the case.

Lots of thread here on set back. Many on chambering factory rounds after clearing a gun. As mentioned above, measure your COL, then rack them through the gun letting the slide slam, measure the COL again.
Click to expand...
I hear you, have read some of them, and understand generally the set back issue, but Lee’s (and other manuals and published sources) says taper crimp doesn’t increase neck tension. Am I wrong?
 
mcb said:
9mm, 40S&W, 45 ACP I rarely crimp. I set me crimp die just to remove the case flare from the powder drop station and maybe .001-.004 less than the nominal case mouth diameter. Never had an issue with bullet moving either way and I shot a lot of my 40S&W and 45 ACP reloads in both semi-autos and revolvers.
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Ironically, despite my best efforts, I cannot get my 45acp rounds to not need a crimp except maybe 10% and then mostly thinner Winchester cases.
 
CQB45ACP said:
but Lee’s (and other manuals and published sources) says taper crimp doesn’t increase neck tension.
Click to expand...

Crimp is to keep the bullet in place, not provide neck tension. Properly applied, it should have very little effect on neck tension, and particularly using a taper crimp, which is normally standard on autoloading cartridge dies. Improperly applied... yes, it can reduce neck tension.
 
Charlie98 said:
Crimp is to keep the bullet in place, not provide neck tension. Properly applied, it should have very little effect on neck tension, and particularly using a taper crimp, which is normally standard on autoloading cartridge dies. Improperly applied... yes, it can reduce neck tension.
Click to expand...
Well now we’re getting into the how and wherefore of what keeps a bullet in place and is it a taper crimp—I’ll just refer to Lees manual cause it’s all I have handy…taper crimping on straight wall auto pistol cartridges doesn’t keep bullet in place.

But thanks for the input I knew this was going to happen:)

Edit: and that’s not a direct quote anyway but I really didn’t want to start that discussion. Sorry I did. All I’m qualified to do is quote published sources and I don’t want to spend my time digging for things I wasn’t interested in discussing in the first case. Sorry
 
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CQB45ACP said:
What rabbit hole — looks like you’re on it brother
My post wasn’t about this was it?
Click to expand...
Don’t be silly. You brought the gasoline and matches. Don’t pretend you weren’t expecting a fire.:rofl:
Crimp and neck tension are two different things, unrelated to one another except through a counter effect/consequential relationship. Neck tension is the result of the bullet being pushed into the brass; a crimp pushes the brass into shape around the bullet. They’re opposites, not codependents.

I have in the past completely skipped the flaring step when reloading rifle and pistol rounds. Most anyone who has used a Lee Classic Loader has done so. Flaring tools are not included in the basic kit. Works fine, no crimp needed, none provided, neck tension is almost always perfect. Almost always…
 
GeoDudeFlorida said:
Don’t be silly. You brought the gasoline and matches. Don’t pretend you weren’t expecting a fire.:rofl:
Crimp and neck tension are two different things, unrelated to one another except through a counter effect/consequential relationship. Neck tension is the result of the bullet being pushed into the brass; a crimp pushes the brass into shape around the bullet. They’re opposites, not codependents.

I have in the past completely skipped the flaring step when reloading rifle and pistol rounds. Most anyone who has used a Lee Classic Loader has done so. Flaring tools are not included in the basic kit. Works fine, no crimp needed, none provided, neck tension is almost always perfect. Almost always…
Click to expand...
I actually did not intentionally do anything of the sort but now see clearly how that’s what happened:)

Just wanted to show how not even removing flare was required which was new to me.
 
My Lee 9mm seating die will remove the belling from the expander dies if set far enough down. My rounds will generally chamber without running through the crimp die. I set the crimp die so it just provides the minimal amount of crimp.
 
CQB45ACP said:
What rabbit hole — looks like you’re on it brother
My post wasn’t about this was it?
Click to expand...

You brought up the subject as if taper crimping is not required based on your 10 examples. Just because they plunked means nothing Did you shoot them, did you measure set back?
Crimp or don't crimp it's up to you. I tried to point out the valid reasons to crimp.
 
I wholeheartedly agree with the "do what works for you" mantra.

I can't help but wonder, however why wouldn't you want to crimp?

Are you on a single stage and it adds another step?
Cutting the thin copper plating?

Curiosity has gotten the better of me :D

I've loaded 9mm since the late 80's and have always "crimped" (more like remove the flair) but the Dillon SD I've use size my cases to the point of leaving a noticeable bulge at the base of my bullets eliminating any chance of the bullet getting pushed back in the case during the feeding process.

And, since I'm reloading on a progressive press I'm already pulling the handle anyway.
ihtJ47K.jpg

I can't tell from your picture if your rounds look like mine.

Also, this little bit of commentary at the end of the description of the 9mm cartridge in my Speer #11 has always stuck in my mind

ACDgaVg.jpg
 
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