Ogive ?

[06shooter]

I found out yesterday that federal uses speer in their fusion line of ammo and speer is used with some of the power shok line .
The 3006 150 gr. in the power shok WITHOUT the speer bullet does real good.
The fusions don't do good whatsoever !

Federal told me that speer and their bullet for the shok line have different ogive shapes ( tangent ) for both .

I know bullet shapes have to do with flight characteristics , but what about it being fired down the tube ?

[Bart B.]

Different rifling angles at its origin coupled with different bullet ogive shapes and how far they jump to the rifling can show a 1/20th to 1/10th MOA change in accuracy at 100 yards; if you and your stuff do no worse than 1/4th MOA.

Otherwise, forget about it. Load the bullets you want to use, then shoot 'em.

New reloaders oft times get bogged down in details that don't really matter and they'll never see their effects. While it's nice to be perfect in all reloading things to start out with, it's much like baking, forming then icing and decorating a wedding cake. Learn the fundamentals, master them, learn their interactions then start thinking about the details for perfection; it'll take much less time and you'll get much better end results.

Most people can handload new cases with proven component recipies and shoot them in their rifles very accurately. After all, that's what commercial match ammo is; stuff that a lot of people shoot very nice in their rifles. One can virtually duplicate factory ammo using the same commercial components assembled the same way and it'll shoot just as good. There's no magic involved, just doing all the right stuff that's not complicated at all.

[06shooter]

I gotcha' Mr.Bart , I was getting .5 groups @ 100 yards with a secant scirocco from the factory with a .090 " jump in my 3006.
Same with power shok with a .048 " jump (tangent.)
The fusions and Hornady interlock , I'm talking about a 2" + group with a heavier recoil than usual in 50 * temps.
All are 150 gr.
Maybe it was a certain powder !

I was testing ammo with a led sled, I have come to learn that sand bag rests and 1 " groups are fine and dandy !

[wogpotter]

It depends on bullet weight to a point (sorry, no pun intended.)
You need to seat at least 1 caliber diameter of depth into the case neck for good concentricity, & depending on weight & ogive shape that moves the contact with the lands closer or further.

The difference is really minor, but it is real.

(Picture (c) Wogpotter 2011)

[Bart B.]

I've no idea where bullets need to be seated 1 diameter back for best "anything" came from. I've violated that concept way too often. Never once had any issues whatsoever. Another old wive's, err... reloader's tale in my opinion.

Where's the reference point on the bullet; base or heel (rear most point at body diameter)?

[wogpotter]

I'm just going from experience.

125 Gr "AK-47" bullets never did well in the L-E when I tried some for a lightweight medium range load. I think it was because of the difference in length from the 174 Gr that the case & throat were designed for. I had the same problem with some Lapua 130 gr .312" bullets as well.

Then when the shortages started I got some Speer 150 Gr SP ammo & it was way, way less accurate then the Hornady 15's I'd been using for ever.

That prompted me to look into off lands Vs seating depth, looking for some kind of "good" compromise. I never did find one, but the Hornady's will shoot as well as any 174/180 Gr bullet. IMO its because of the ogive shape being better suited to the case & chamber than the others.

[IllinoisCoyoteHunter]

Learn about secant, tangent, and hybrid ogives. If it was not a detail worth worrying about Brian Litz at Berger Bullets would be out of a job. Bullet jump can affect accuracy more than you think, especially with secant ogives. I consider understanding ogives a BASIC of reloading.

This is a good start : http://www.accurateshooter.com/balli...ogive-bullets/

[06shooter]

I read the accurate shooter article , saying the secant jump needs to be closer contradicts the scirocco bullet in my rifle. The scirocco jumps .090 " secant.
The shok jumps .048" tangent and group nice.
I measured a Barnes ttsx and it's a .120" jump , I haven't shot those yet and they are secant.

Win. ballistic tips are .022" jump 168 gr .
Tangent.
Maybe I'm missing something !

[IllinoisCoyoteHunter]

Yep. You are missing something. LOL!

You will find that loads vary from rifle to rifle. Competition rifle chambers are different than stock rifle chambers. Stock rifle chambers are different than other stock rifle chambers. You get the point.

What works in one rifle may not work in another. BUT, if you posses the knowledge of what "generally" works and the reasoning behind it, you will have a good place to start and further tweak your load development.

The great thing about reloading is that if something doesn't work, we can change it. If something works, we can tweak it and maybe make it better. It's part of the reason we reload. Commercial-ammunition shooters don't have this luxury.

OK, there's my two posts for the year...I will go back under my rock now...

Good luck, and be sure to post some pictures of targets. We always like looking at targets!

[06shooter]

I gotcha' thanks !

[Gunplummer]

I always believed that too extreme of a curvature (ogive) leaves less flat area to stabilize the bullet when going down the barrel. It seems to be more of a problem with old cut rifling. Could just be coincidence with the bullet/barrel combinations I have used over the years, I don't know.

[Bart B.]

I think, 06shooter, you need to learn how get into, sit in, buckle up the 5-point belt, learn the instrument panel gauges and controls functions plus how to use them then drive your Ferrari slowly around the test track before trying to win the Grand Prix F1 world championship with the first tank of fuel.

Learn the fundamentals of the various tools then make safe and functional ammo. Don't worry about squeezing out the last 1/100th inch of accuracy yet. Put bullets on paper to see what happens. Then do it again several times until it becomes second and third nature to you.

Next, find out what the Grand Prix drivers do to just finish the race; all in one piece with their Ferrari's in good shape. Then you'll better understand and be able to learn how to operate the cars controls and put in and fit the special things that'll let you win the championship; if you're a good driver.

[IllinoisCoyoteHunter]

Not quite sure what is so complicated about ogives??? This is basic reloading stuff. Learning how to properly bump a should back on a rifle case and understanding what the heck "headspace" is, IMHO, WAY more complicated than understanding the different types of ogives and how they generally perform....their strong points and weak points.

I think that understanding ogives will help you choose a bullet that may best suit your application. Knowledge is power. Rifle bullets aren't cheap.

Bart, I respectfully disagree with you. I guess we can agree to disagree!

[06shooter]

Roger that Mr. Bart , when I get the keys and a full tank, I'll come by and scoop you up and we'll see how she handles !

[06shooter]

I'll holla' back when comes time to bump shoulders !
I really do thank everyone for taking their time answering my questions !

[Bart B.]

I. C. H.,

I never got concerned about ogive shape A over B. Never worked up any of my favorite loads with new component lots or barrels, either. Maybe I'm not up to basic reloader's level yet.

[IllinoisCoyoteHunter]

Well, I don't know you or your reloading skill level. I just think that telling an inquiring mind not to worry about something is the easy way out. Just my 2 cents.

When I began learning reloading, I wanted to learn about EVERY aspect of it. I guess we should just stop learning about certain things...

[Longshot4]

IllinoiseCoyoteHunter I think you are one of those complicated guys that like to laugh at others. I would not consider the ogive common knowledge at all with handloaders or you would not see the Berger boys writing about it.

[IllinoisCoyoteHunter]

Everyone is welcome to learn as much or little reloading knowledge as they prefer. I prefer to learn as much as I can, and am still learning to this day. Laughing at people...nawww...I try to help and answer questions when they are posed by inquiring minds.

[Mike / Tx]

Summing up what has already been posted by others, while it is something to know when working with one or another type or design of bullet, the end result is what your particular rifle likes or dislikes.

When I try out a new bullet I look things over and compare one to another, but that is about it. I am mainly concerned with the bearing surfaces or the actual bullets weight and overall length.

Past that I usually am loading for hunting rifles which feed form the magazine, and as such I used that lenght as my max OAL of the loaded round. I work up loads using this length and once I get to the top end I might have a shootable load or not. It simply depends on if I have seen anything that suits my fancy. If nothing has come together I will try seating the bullets deeper using .005" increments. Some might find this a bit short, but on more than several occasions I have found I skipped right over perfect shooting loads by using larger jumps in seating. I finally decided that it was just as easy to move slowly than to repeat things.

If after moving the depth in maybe .050 to .100" I haven't seen anything trying to come together I change powders and start over. It has been rare that something didn't group after moving that far but it has happened.

Other than that I really don't sweat the type ogive most any bullet has. I'm more interested in what it does when it get to the intended game than I am with how it looks on the way.