Adding cannelure to bullets

[shazz]

G'day fellas,

I'm asking about something I've just discovered here, just to learn.

The company Corbin does hand cannelure tools. You can add cannelures to bullets and cases (btw, what are they added to cases for? )

If you've got a bullet that's not designed with a cannelure, why would you add one?

Would it muck up the properties of the bullet? The BC? How it compares in a load compared to a non cannelured bullet?

[Chronos]

The cannelure it there to give the case mouth something to grip into when you add a crimp... which I've never done

adding a cannelure and a crimp can cause additional pressure so make sure you work up your load again to be safe

Chronos

[yoshie]

A lot of hunting bullets have cannulars. Hunting bullets aren't usually hanging out of the case so they nearly touch the lands, they are usually set back more for reliable feeding and usually crimped. The cannular provides a secure, positive grip for the case to crimp on to. Also military ammo usually has a cannular for the same reason. Ballistic coefficient isn't a variable until ranges get out part 500m.

[MeccaOz]

Ive just been looking at the tool you mean, I think it could help out more than hinder in a hunting scenario anyway. Might have to get one

[Chronos]

Another thing I forgot to mention about this is that a cannelure can help retain the jacket to the core, improving weight re tension in a hunting bullet.

Remmington corelokt and a couple of others claim this in their marketing, so it must be true. Lol

Chronos

[Warrigul]

G'day fellas,

I'm asking about something I've just discovered here, just to learn.

The company Corbin does hand cannelure tools. You can add cannelures to bullets and cases (btw, what are they added to cases for? )

If you've got a bullet that's not designed with a cannelure, why would you add one?

Would it muck up the properties of the bullet? The BC? How it compares in a load compared to a non cannelured bullet?

A cannelure and subsequent crimp(if it is a roll crimp, a LEE factory crimp doesn't need a groove) removes most of the variables when it comes to neck tension in the same way that seating to the lands does- it gives a consistent start pressure. I.e. it allows pressure to build up before the bullet leaves the case.

Bullet retention is also a benefit but is secondary to accuracy improvement in my humble opinion.

By neck crimping certain rounds I have seen a MARKED improvement in group size, I won't load .303 any other way(except for one custom range rifle where it has been chambered especially to run ammo just off the lands- which was actually cheating in the day it was used). However if the projectile is seated close to the lands there is no real improvement to be gained.

I am only guessing here but: I don't know why you would add a cannelure to a case other than a straight walled pistol case (like you see in .357 sometimes) where the possibility exists for the projectile to travel backwards under extreme recoil.

You would have to be very particular to want to add your own cannelures.

[shazz]

The cannelure it there to give the case mouth something to grip into when you add a crimp...

G'day,

Yeah I know for crimping the bullet. They show adding cannelure to the brass too like this...



I'd never seen that before... It's for... What?

[shazz]

Ive just been looking at the tool you mean, I think it could help out more than hinder in a hunting scenario anyway. Might have to get one

Yeah this was the one.

http://www.corbins.com/hct-1.htm

The HCT-1 tool.

[salate]

Remmington corelokt and a couple of others claim this in their marketing, so it must be true. Lol

Because advertising never lies... No wait...

[Arth]

I am only guessing here but: I don't know why you would add a cannelure to a case other than a straight walled pistol case (like you see in .357 sometimes) where the possibility exists for the projectile to travel backwards under extreme recoil.

Or tube loading mags too I guess?

[shazz]

I am only guessing here but: I don't know why you would add a cannelure to a case other than a straight walled pistol case (like you see in .357 sometimes) where the possibility exists for the projectile to travel backwards under extreme recoil.

Or tube loading mags too I guess?

Both of those make sense

[MeccaOz]

The cannelure it there to give the case mouth something to grip into when you add a crimp...

G'day,

Yeah I know for crimping the bullet. They show adding cannelure to the brass too like this...



I'd never seen that before... It's for... What?

Some people dont put a real crimp on there bullets, usually competitive guys / girls , because it keeps the pressures lower, so crimping the case will stop the bullet being pushed back in some actions.

Yeah Shazz thats the one I was looking at myself,

[shazz]

so crimping the case will stop the bullet being pushed back in some actions.

Yeah, I get ya.

[Norton]

You would have to be very particular to want to add your own cannelures.

I reckon, hey.

Like there isn't enough to do with it already.