Tangent vs Secant.

[Paddyd]

I like Sierra matchkings because they're a tangent ogive and very easy to tune.
I've noticed the Hornady HPBT match bullets are all secant and seem quite a bit more finicky as far as seating depth. They seem to require more adjusting as throat wears. My question is why aren't more bullets just of hybrid design which to me would make things much better all around?
Why is Hornady locked in with secant bullets and most Sierras tangent?

 

[ELR LVR]

I like Sierra matchkings because they're a tangent ogive and very easy to tune.
I've noticed the Hornady HPBT match bullets are all secant and seem quite a bit more finicky as far as seating depth. They seem to require more adjusting as throat wears. My question is why aren't more bullets just of hybrid design which to me would make things much better all around?
Why is Hornady locked in with secant bullets and most Sierras tangent?

Just a guess here, and I agree with your assessment
Taking all things into consideration ...
...Cost
Just by looking and comparing the 2, you can tell a Tangent Ogive of a given radius is likely a more complicated compound curve to Grind/Mfgr. than a Secant Ogive
Hornady's are usually cheaper, and this may be one reason
Although their A-tips look more like a Sierra, and we also see their cost is way up there.
I guess we're paying for the type of Ogive we want too

 

[Doom]

Marketing. But seriously most of Sierra's bullets have been tangent but some of the newer ones tend to be either Secent or Hybrid. It isn't so much the ogive design that matters it the resulting BC and you can see the difference. I have the 308 168 Hornady Match but if it's a secant ogive its not very obvious. Doesn't show up in BC. Also didn't mention being secent in the 8th Edition of their handbook.

I can't tell you for sure what Sierra's newer bullets are, such as the 169 SMK but I suspect it is a hybrid ogive along with the closed tip and shallower boat tail. As for Hornady I take much of their advertising as mostly BS. They do have a big following with the ELD series so I will take it these bullets are good.

 

[geo.ulrich]

Just a guess here, and I agree with your assessment
Taking all things into consideration ...
...Cost
Just by looking and comparing the 2, you can tell a Tangent Ogive of a given radius is likely a more complicated compound curve to Grind/Mfgr. than a Secant Ogive
Hornady's are usually cheaper, and this may be one reason
Although their A-tips look more like a Sierra, and we also see their cost is way up there.
I guess we're paying for the type of Ogive we want too

Nope the secant is more difficult to figure

 

[geo.ulrich]

I like Sierra matchkings because they're a tangent ogive and very easy to tune.
I've noticed the Hornady HPBT match bullets are all secant and seem quite a bit more finicky as far as seating depth. They seem to require more adjusting as throat wears. My question is why aren't more bullets just of hybrid design which to me would make things much better all around?
Why is Hornady locked in with secant bullets and most Sierras tangent?

they do it to increase BC numbers which is a huge selling point

 

[ELR LVR]

Nope the secant is more difficult to figure

The Secant ogive as picured here on (Right) is almost more of a straight line as opposed to the smooth radius curve of a Tangent Ogive like a Sierra.
Such as mentioned in the "Abrupt" juncture between the Ogive and the bearing surface
I would have thought a simple change in angle
Would be more of a simple item to grind, make etc as in reamers and tooling
As opposed to a smoothly tapering off radiused ogive which would be more complicated to correctly grind the same each and every time for tooling.
----------------------------------
I stand corrected then

 

[ShaunBrady]

The short answer is BC and the shooting community's resistance to change. Enough customers don't want their old favorites updated to justify continued production.

The classic SMKs have a nose radius of about 8 calibers that makes it easier to blend into the bearing surface. Their newer pointed SMKs have an advertised nose radius of 27 calibers and a much higher BC. The longer, pointier, nose doesn't blend as well to the bearing surface without some massaging that didn't appear until the Berger Hybrids. The Tipped SMKs are also VLD/secant ogive designs. According to the Litz Bullet Book, even some of the classic SMK line are pretty close to a secant ogive design.

Berger makes both hybrids and classic secant ogive VLDs.

Hornady is pretty much a secant ogive company.

Heavier bullets sometimes have a bore riding section ahead of the bearing surface. I think that's a bigger deal than the final transition to the bearing surface. Those bullets are not often used for 100 yard groups because of the recoil.

I don't shoot bench rest, but the common generalities on finicky secant ogive designs haven't really shown up in my guns. My old R700 VS 308 shoots the same size groups with 175 SMKs, 155 Amax, or 168 ELDm ammo. ATips are the first thing I try in my ELR guns and haven't I found a bullet with better out of the box downrange performance in 7mm, 30, or 338.

 

[Rob01]

I like Sierra matchkings because they're a tangent ogive and very easy to tune.
I've noticed the Hornady HPBT match bullets are all secant and seem quite a bit more finicky as far as seating depth. They seem to require more adjusting as throat wears. My question is why aren't more bullets just of hybrid design which to me would make things much better all around?
Why is Hornady locked in with secant bullets and most Sierras tangent?

Never found the Hornady bullets hard to find a load or finicky about depth. I load them at SAAMI and also at .020” off lands and they both shoot great. That was AMAX, ELD-M and ATips in multiple calibers.

 

[Idaho-Lefty]

This ^^^
The 52 gr A-Max, shot Best in my .22-250 Rem and, the 130 gr. ELD-M's shoot Best, in my 6.5 Creed.
Nothing has ever Beat them for,.. SMALL Group's,.. in either Rifle.
The 107 gr. SMK's ( New "pointed" One's and, JAMMED ) work better than anything I've tried, so Far, in my 6 XC.
Tried, the 130 gr., Berger, ( Secant Ogive ) H-VLD's, in my 6.5 Creed, Yikes "Fussy" & "No bueno", so Far !
I'll Be sticking WITH, the Hornady, "M's", in the 6.5 Creed. !

 

[geo.ulrich]

View attachment 1682028
The Secant ogive as picured here on (Right) is almost more of a straight line as opposed to the smooth radius curve of a Tangent Ogive like a Sierra.
Such as mentioned in the "Abrupt" juncture between the Ogive and the bearing surface
I would have thought a simple change in angle
Would be more of a simple item to grind, make etc as in reamers and tooling
As opposed to a smoothly tapering off radiused ogive which would be more complicated to correctly grind the same each and every time for tooling.
----------------------------------
I stand corrected then

a secant radius is still a radius you are confusing a spire point with a secant. the secant has a more abrupt blend point then the tangent and thats just the beginning figuring the point to end the transition on a secant to establish the bearing length that is wanted is more of a chore. a tanget is easy just move over from the base the number of calibers and swing a radius... who is making reamers for this they dont cut carbide...

 

[Infrequent Shooter]

Is there a way to apply Fibonacci ratio/1.618 to bullet design? I don't know didly, but I do know there is no free lunch in physics. I am curious what a bullet would look like if 1.618 ratio were used in its design. I will ask AI about it. Didn't find much helpful. One offshoot could be advanced aircraft fighter design. More capable than prior designs but also less stable. That has probably been true since powered flight.

 

[jackieschmidt]

A lot of short range Benchrest Bullet Makers are making what is called a “double radius boat tail”.
The story goes They became really popular back in the early 2000’s when a very well known shooter and bullet maker “accidentally” reburned a die that had a combination of a real high number ogive going into a smaller number. The bullets shot really well and others followed. Lester Bruno’s famous “OO” was such a bullet, and they even helped shooters like me be competitive.

I think it is the norm now. I acquired a set of Ronnie Cheek’s BT dies and they are such a configuration.