what is an ogive and a couple other questions

[bbhank]

hey guys,

I'm building this custom arisaka in 30 br. So I'm shopping for bullets today on the net and I keep running into that specification and I'm not sure what ogive means. I was also looking at B.C. and they had two ratings G1 and G7, anyone know what that refers to.

Thanks

 

[ChrisGarrett]

Re: what is an ogive and a couple other questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: send it 77</div><div class="ubbcode-body">hey guys,

I'm building this custom arisaka in 30 br. So I'm shopping for bullets today on the net and I keep running into that specification and I'm not sure what ogive means. I was also looking at B.C. and they had two ratings G1 and G7, anyone know what that refers to.

Thanks

</div></div>

I'm up late and cracking my last beer, so I'll give this a whack.

Ogive (pronounced O-Jive) is the radius, or tangent (I'm an English Lit. major) of the shape of a bullet's frontal area ahead of the main body/bearing surface, the curved part between the flat bearing surface, to the tip. I believe we have tangential (more curved) ogives and secant ogives (more abrupt, less curvy, more straight after the bearing surface to the nose) like a dart or cone shaped shape.

G1 and G7 refer to the ballistic coefficient (measurment) of a particular bullet and it's ability to slip through the wind with minimal drag. G7 seems to be a lower number than G1. I'll let the experts chime in and erase everything I've written.

Good day to you, kind sir.

Chris

 

[Mag 300]

Re: what is an ogive and a couple other questions

Chris
Nice beer crack and comments. I agree so waiting for the experts to come on to see " once again" how much I dont know
Bill

 

[Enios]

Re: what is an ogive and a couple other questions

Yep that looks pretty good to me. The G7 is more for the long tapered target and hunting boat tailed bullets and G1 for hunting bullets. G7 when figured into a ballistic calculator even tho the number is lower will run about the same. Berger is listing their bullets with both BC's and if you run the number with a calculator that you can chose G1 or G7 numbers wont vary a lot but enough for you to see the difference. On a 95 Berger in 6 MM it's not but about 4 or 5 fps slower for the G7 at 1000 yds but it's suppose to be more accurate. Thing is Ballistic programs are computer figured numbers and nothing replaces real world but they will get you in the neighborhood. Big thing the higher the BC the longer the bullet with hold before going subsonic and the greater the weight even tho slower will give you more bang for your buck at greater distance. In my 308 I have a 190 load running 2610 thats holds up further past 1000 than a 175 load running 2760 fps and has a good bit more stopping power. No expert by any standards but thought this might help a little more. Chris was right on.

 

[918v]

Re: what is an ogive and a couple other questions

I'm no expert, but jumping into a 30BR not knowing what "ogjive" means is not a good idea.

 

[InTheWeeds]

Re: what is an ogive and a couple other questions

Not the best pic but...

 

[bbhank]

Re: what is an ogive and a couple other questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 918v</div><div class="ubbcode-body">I'm no expert, but jumping into a 30BR not knowing what "ogjive" means is not a good idea. </div></div>

thank you to everyone for the info and not to worry i have adult supervision

 

[Victor N TN]

Re: what is an ogive and a couple other questions

I know this was not part of the original question. But ogive does mean the area ahead of the bearing surface and on most rifle bullets is calculated in bullet diameters it takes to get that radius.

The radius of a 7 ogive bullet is equal to the bullet diameter X 7. The higher the ogive number means the bullet has a sharper point on it. VLD bullets usually have an ogive value from 11 to 14.

Ogive also means the point where the contact is first made between the bullet and the lands of the barrel. That's the point that measurements are made when measuring from base of a bullet to the ogive. Most of the time this is a more accurate way of measuring bullets instead of overall length.

After reading this post. I think I probably made it about as clear as mud.