Bullet & Case nomenclature

[Wobbly]

Please look this over for additions and corrections. Your comments sought. Thanks.

[2bfree]

What is the difference between a crimp grove and cannelure ?

[Raven45]

Looks good and I hope your reference material is used.

I continue to hope that at some point a few folks will learn that a BULLET is called a BULLET and NOT a BULLET HEAD!

And that the term BULLET is NOT correctly interchangeable with the term CARTRIDGE!

Understanding the difference between a CLIP and a MAGAZINE would prove to be valuable knowledge, as well!

I suppose I am an eternal optimist, though!

[Wobbly]

What is the difference between a crimp grove and cannelure ?

Both are depressions in the bullet into which a roll crimp can be swaged by the crimp die. So they serve the same purpose. A "crimp groove" is made into the bullet by the initial casting or stamping process, and is therefore usually found on lead bullets.

However, due to the construction technique used in making a jacketed bullet (pressing a lead slug into a tight-fitting copper jacket) there can be no irregularities in the jacket before assembly. Therefore, a groove is added to the bullet after assembly by a rolling process similar to knurling. The process leaves a neat row of machine marks in the indention, and the resulting groove we call a "cannelure".

You can easily see the cannelure on these two 357M bullets...

[Wobbly]

I continue to hope that at some point a few folks will learn that a BULLET is called a BULLET and NOT a BULLET HEAD!

The hipster term "pill" drives me crazy. 

[painter]

I continue to hope that at some point a few folks will learn that a BULLET is called a BULLET and NOT a BULLET HEAD!

The hipster term "pill" drives me crazy. 

I heard it was a short trip.

[IDescribe]

I continue to hope that at some point a few folks will learn that a BULLET is called a BULLET and NOT a BULLET HEAD!

The hipster term "pill" drives me crazy. 

Pill might be my biggest pet peeve (until I remember the other biggest   ), and it can be made more annoying by describing it as under some amount of powder.

"I like 124gr pills under 4 grains of Titegroup."

Under?  I guess you can orient a bullet any way you like, but the bullet is rarely under the powder except when sitting in an ammo box or in a gun that's pointed at the ground.

Thanks, though, Wobbly.  I learned two new ones.  I thought the web was the reinforced bit of case wall just above the extractor groove, and I thought cannelure and crimp groove were the same thing. 

[Wobbly]

Thanks, though, Wobbly.  I learned two new ones.  I thought the web was the reinforced bit of case wall just above the extractor groove, and I thought cannelure and crimp groove were the same thing. 

If you're depending on me, then I think you're backing up ! 

Honestly, I think a cannelure is a type of crimp groove. But then what do you call the molded groove ?

People don't call it the "cannelure crimp groove", they simply call it "the cannelure". So to me that sort of leaves "crimp groove" by default to the molded versions.

But what do I know ?    That's why I'm asking !

[IDescribe]

Searched around, found places using them interchangeably and not.  ONE place that seemed to differentiate said something from which you could infer:

A cannelure is a shallow crimp groove for jacketed bullets where you would not want as deep a crimp groove as you would in lead bullets.

[Mods added quote]

[M1A4ME]

I've always seen the crimp grooves in a cast lead bullet as looking different than the cannelure on a jacketed bullet - but used them the same way.  Seat the bullet till either/both are in the right place that the top of the case (mouth) lines up with them for the crimp/bell removal stage of reloading. 

Yeah, ID, I shake my head every time I see someone type that their bullet is under the powder.  But I think you've got it worse than I do.

[tdogg]

So how are you supposed to pronounce Ogive?
Is it:
Oh-giv <--- how I pronounce it normally
Oh-gIve
Oh-jive
Ah-jive
Ah-giv
Ah-gIve

I continue to hope that at some point a few folks will learn that a BULLET is called a BULLET and NOT a BULLET HEAD!

The hipster term "pill" drives me crazy. 

I heard it was a short trip.

This cracked me up!

I think we need the slang/redneck version of this diagram for reference so we can communicate with all potential users appropriately.

Cheers,
Toby

[Wobbly]

So how are you supposed to pronounce Ogive?
Is it:
Oh-giv <--- how I pronounce it normally
Oh-gIve
Oh-jive
Ah-jive
Ah-giv
Ah-gIve

#3   Oh-Jive  (with the accent on the second syl-loble)

[Wobbly]

I thought the web was the reinforced bit of case wall just above the extractor groove, and I thought cannelure and crimp groove were the same thing. 

From the Lyman book, the Web seems to be the portion holding the Primer Pocket. That is to say, the portion at the Head laying at 90? to the Wall.

I'm changing my mind on the Cannelure. The Cannelure is any groove for crimping. It can be molded in or machined in.

Searched around, found places using them interchangeably and not.  ONE place that seemed to differentiate said something from which you could infer:

A cannelure is a shallow crimp groove for jacketed bullets where you would not want as deep a crimp groove as you would in lead bullets.

I think that guy knew what he was trying to say, but got it screwed up in the wording. You only need so deep of a crimp groove on any bullet. You don't need a larger groove on a 9mm jacketed bullet than you do on a 9mm lead bullet.

It's much more likely it's driven by the manufacturing. When the cannelure is embossed into a copper jacket, you want it minimized to reduce the manufacturing costs. When the cannelure is cast into a lead bullet, the casting material will not allow fine detail.  So it naturally ends up being larger.

 

[M1A4ME]

The only time I've used a "heavy" crimp is with .357 and .44 magnum lead bullets. 

I've never had bullets jump forward, but I've read about it happening to others.  Those bullets have a much more pronounced groove around the bullet than jacketed bullets with a cannelure.

[tdogg]

So how are you supposed to pronounce Ogive?
Is it:
Oh-giv <--- how I pronounce it normally
Oh-gIve
Oh-jive
Ah-jive
Ah-giv
Ah-gIve

#3   Oh-Jive  (with the accent on the second syllable)

Thank you!  I guess I will have to start retraining my brain to say it that way.

Cheers,
Toby