effect of boat tail bullet vs crowning

[boblee]

is it possible that a flat base bullet is more forgiving for so so crowning....this morning i was shooting my 308w 700vs 20inches barrel(a former 26 inches)with 150 winchester power point factory ammo ant got a lucky .28 group at 100y i tried next a handload neck size 165 accubond with 43.5 imr 4064 and got .52 group at the same distance but with a flyer .75 a part .is it the crowning since accubond are boat tail...i dont kown and i am not sure since at the end there was much barrel haze..

 

[guntech]

I believe boat tail bullets require manufacturing to closer tolerances than a flat based bullet to shoot as accurately. When Terry McCracken was making Benchrest quality bullets he commented to me about that... and how much quality bullet making dies cost.

I don't believe that there is such a thing as a more forgiving crown. It requires that is burr free and square to the bore...

 

[AlexF]

Flat Base Bullet Design

Berger produces a full line of flat base bullets in several calibers. We consider the flat base bullet a staple of extreme precision bullet makers. These bullets are used most often by short range target and varmint shooters who are focused on the tightest possible accuracy. The ability for a bullet maker to produce very accurate flat base bullets is a significant indicator of how focused that bullet maker is on consistency. Flat base bullets are the easiest to make consistent since flat is always flat. No boat tail tooling or considerations during the manufacturing process need be made. The vast majority of flat base bullets are made with a tangent ogive which is easier to produce than the secant ogive. The tangent ogive is also easier than a secant ogive to make shoot well. A tangent ogive of the same length as a secant ogive will not perform as well in the wind however these bullets are used primarily for 300 yards or less so this is of little concern.

From Berger Bullet bullet design page
http://www.bergerbullets.com/Information/Lines%20and%20Designs.html

Simply put flat base and tangent ogive are easier to precisely manufacturer than any other bullet design.

Alex

 

[Wanted]

Here is an excellent article that goes into the whole science behind this. A great read and not too long.

http://www.appliedballisticsllc.com/index_files/BulletDesign.htm