new bullet lot and big Ogive difference...

[justinbaker]

so im loading some hornady 178 HPBT bullets for my 308

the first lot, which i have been shooting well has the bullet ogive at .687 so my loaded round is 2.173 from base to ogive

new lot is .719

that seems like a huge difference to me (.032)


so with these new bullets should i still seat to ogive of 2.173? which means i will be seating the bullet .032 deeper


eta: gun is a factory remy 700 so not even close to the lands

coal of 2.82

 

[427Cobra]

Re: new bullet lot and big Ogive difference...

Seat them by ojive length, so all the bullets engage the rifling the same

 

[justinbaker]

Re: new bullet lot and big Ogive difference...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 427Cobra</div><div class="ubbcode-body">Seat them by ojive length, so all the bullets engage the rifling the same </div></div>


forgot to mention its a remy 700 so im no where near the lands.

coal of 2.82

will it affect the velocity/pressure much by seating .032 deeper

 

[QuiggyB]

Re: new bullet lot and big Ogive difference...

Seating it deeper could. I would not be around max load until you tried it. Also I personally would measure where these new bullets hit your lands if you think you are anywhere near them. The gauges and the rifle barrel dont always agree.

 

[BCP]

Re: new bullet lot and big Ogive difference...

So basically the bullets are shaped differently but the same length so when you seat to the old ogive measurement you get 2.79COAL? Is that what you mean?

 

[justinbaker]

Re: new bullet lot and big Ogive difference...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BCP</div><div class="ubbcode-body">So basically the bullets are shaped differently but the same length so when you seat to the old ogive measurement you get 2.79COAL? Is that what you mean? </div></div>

these are the same model of bullet, so the "shape" is the same

the .719 is slightly longer

but yes, i will get a coal of 2.79 if i seat the new bullets based on the old ogive measurement

 

[justinbaker]

Re: new bullet lot and big Ogive difference...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: QuiggyB</div><div class="ubbcode-body">Seating it deeper could. I would not be around max load until you tried it. Also I personally would measure where these new bullets hit your lands if you think you are anywhere near them. The gauges and the rifle barrel dont always agree. </div></div>


there is no chance ill hit the lands in this gun and still feed from the mag

my lands are somewhere around 2.93 with my current bullet, so im not worried about that.

but im at a charge of 44.6, which is pretty close to max in my gun

 

[427Cobra]

Re: new bullet lot and big Ogive difference...

If your going to sort bullets you need to do it by bearing surface, I use 2 Hornady tools to do this and a digital caliper, using only 1 is not a true reflection of the consistentcy of your bullets, and yes always seat by Ojive length with whatever if any COAL restrictions

 

[QuiggyB]

Re: new bullet lot and big Ogive difference...

If the 44.6 wasnt showing pressure signs I think you'll be fine to test a couple of rounds with it seated back to the same length per the ogive. If you see pressure signs stop and back off the load.

 

[jhelmuth]

Re: new bullet lot and big Ogive difference...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 427Cobra</div><div class="ubbcode-body">Seat them by ojive length, so all the bullets engage the rifling the same</div></div>

Yep... that is the right way to do it. I too have found some inconsistancy in the Hornady pills. I try to stay away from them now. Only Sierras and Bergers for me.

 

[LostinAR]

Re: new bullet lot and big Ogive difference...

What powder are you using?

 

[justinbaker]

Re: new bullet lot and big Ogive difference...

Im using varget. 44.6 grains

heading to the range after work today. gota match Sunday soi need to figure out how these are going to shoot

 

[Wannashootit]

Re: new bullet lot and big Ogive difference...

Question about this...
Doesn't the seating die engage the bullet at same point (diameter) on the ogive, regardless of where it falls on the OAL of the bullet?

If so, then this inconsistency would be irrelevant since it's going to be seated to the same depth from the lands, regardless of the bullet length.

 

[lonely_wolf]

Re: new bullet lot and big Ogive difference...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Wannashootit</div><div class="ubbcode-body"> If so, then this inconsistency would be irrelevant since it's going to be seated to the same depth from the lands, regardless of the bullet length. </div></div>

I've also wondered this. I'm using a Forster Seater and the directions state it seats off the bullets ogive. So I figure there's no point in checking bullet ogives..?

 

[Wannashootit]

Re: new bullet lot and big Ogive difference...

I use the OAL gauge (with whatever bullet I'm testing) to get the distance to the lands- of course it's measured to the ogive...

Then I adjust the seating die until the length with the bullet comparator matches what I got (less jump) from the OAL gauge.

I never measure actual OAL (other than to be sure I'm within specs), but since the seating die engages the bullet on the ogive- and not the "tip"- I can't see how there would be any variation. The distance from the ogive to the rifling should always be the same, it's the distance the bullet is seated into the case that would vary.

At least, that's the way I see it...