Horty
Well-Known Fanatic
Does a cannelur affect bullet performance? At 100 yds? 300 yds? 1000yds?
Side question - what does Boat tail give you over flat base?
Side question - what does Boat tail give you over flat base?
Does a cannelur really affect performance?
- Thread starter Horty
- Start date
Mitch Rapp
Well-Known Fanatic
A boat tail, if I remember correctly, helps in two areas. One is as the bullet drops out of supersonic flight, and the other is with wind. Basically it makes wind pass over it from the side a bit easier to help with wind I think. You have to remember a bullet is not an arrow, it maintains it's attitude in flight, even as it falls.
Burk Cornelius
Regular guy
I must confess, I had to do this http://bit.ly/QbSgnt
Spiff
Semi-Pro
A boat tail makes the bullet more aerodynamic, which is quantified by the ballistic coefficient. The BC is basically a drag measurement, less drag means your bullet loses less velocity, which means it gets to the target quicker, which means it drops less. The faster it gets to the target, the less it's affected by wind. A higher BC means the bullet has less drag.
Cannelures will affect accuracy, and what you're shooting will determine where you notice it. If you're shooting 3 gun at 4 MOA targets, you probably won't notice it at all. If you're shooting benchrest competitions with .1" groups at 100 yards, you'll notice. But most bullets that are cannelured are not in the super matchy category, although you can get Sierra 77gr with a cannelure. I've shot sub MOA groups at 200 yards with Hornady 55gr FMJ cannelured bullets.
Cannelures will affect accuracy, and what you're shooting will determine where you notice it. If you're shooting 3 gun at 4 MOA targets, you probably won't notice it at all. If you're shooting benchrest competitions with .1" groups at 100 yards, you'll notice. But most bullets that are cannelured are not in the super matchy category, although you can get Sierra 77gr with a cannelure. I've shot sub MOA groups at 200 yards with Hornady 55gr FMJ cannelured bullets.
dennishoddy
Moderator
Pretty much what Spiff said. I've seen pics of flat based bullets shot through smoke with a high speed camera, vs a boat tail. The slip stream behind the boat tail is very smooth. The flat base is really turbulent in the pics.
A cannalure will add to the turbulance.
For the record, Sierra has won tons more long range matches than any other bullet manufacturer, and they don't have a cannelure, and all are boat tail, and Hollow Point.
A cannalure will add to the turbulance.
For the record, Sierra has won tons more long range matches than any other bullet manufacturer, and they don't have a cannelure, and all are boat tail, and Hollow Point.
Spiff
Semi-Pro
Nah, you can get a 55gr Sierra FMJ w/ cannelure (as well as a Sierra 77gr BTHP w/ cannelure, and flat base bullets, and hunting bullets, and etc.) but the really good ones for long range accuracy are the BTHPs. 
That said, Sierra is the cheap expensive bullet, some of the custom bullet makers destroy Sierra on BC because they're more flexible on newer ideas. But Sierra makes an excellent bullet for just about everything!
That said, Sierra is the cheap expensive bullet, some of the custom bullet makers destroy Sierra on BC because they're more flexible on newer ideas. But Sierra makes an excellent bullet for just about everything!
Corey
Well-Known Fanatic
I agree with what spiff said above
advantage to boat tail in 3 gun IMO is when loading bulk card board killing ammo they are slightly easier to load than a flat base. The first 200 bullets I reloaded in .223 had a flat base after that I made sure everything had a boattail since I typically don't chamfer .223.
dennishoddy
Moderator
Attachments
Spiff
Semi-Pro
This is true, boat tails are way easier to load when you want to crank them out!
Definately no arguement here!!!!
