First experience with cannelure bullets...

[Droppin Deuces]

Do I have to crimp? Is there a disadvantage to not crimping?

[rsrocket1]

No need to crimp just because there is a cannelure on it. I use .224 fmjbt's w/c and never crimp them. The neck tension is sufficient. Same with my .308 bullets. Crimps are usually used to prevent setback in tube fed guns, revolvers, rounds that expect rough handling, or military rounds where they don't care about reloading and the priority is 1st time reliable shot even if it is bumped and banged around for 10 years before it is shot.

A misconception is that the crimp will do a better job at keeping bullet velocities consistent. Proper case preparation leading to consistent neck tension and using the right powder are more important than a crimp for that.

my $0.02

[Sheldon]

On calibers where the bullets have a propensity to get pushed in during recoil, like a tube magazined round (lever action) or pulled out of the case, like a heavy recoiling revolver, a crimp is needed and used. If you do need to crimp the bullet, then you will need to pay attention to seating depth so the cannular is located where you can crimp on it.

On box magazine fed calibers it may not be needed. If I am not crimping at all and solely relying on neck tension, I prefer a bullet without the cannular as it will not ever help accuracy and can effect it negatively. If the cannular is there I completely ignore it.....don't worry about its location relative to where the case mouth is nor crimp on it.

[Droppin Deuces]

Got it. That's why I always come here first Thanks, guys!

[mif_slim]

yuppers, I've used a lot of cannelure bullets and I've never crimp them unless I feel like it.

[fairfaxjim]

...
If you do need to crimp the bullet, then you will need to pay attention to seating depth so the cannular is located where you can crimp on it.

....

This can be a problem in some cases. The two do not always line up at the desired seating depth, and some not all cannulars are created equal, they can and do vary.

[Divernhunter]

All pistol bullets are crimped except for rifle rounds in my encore pistol. All rifle rounds are not crimped from 204Ruger thru 338win mag/45-70 and even my 50bmg(single shot 50bmg rifles).