.308 Ogive Advise

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Super Sneaky Steve

New member
Hello everyone.

I've got a brand new Rem 700 in .308 Win and I'm trying to make the perfect cartridge.

I'm loading Hornady 165gr BTSP Interlock bullets #3045. My first batch I loaded according to my Hornady loading manual. With this spec I have an OAL of 2.750. At this length the ogive measures 2.159.

From my measurements the ogive touches the lands at 2.323 so at the depth I loaded these rounds I have a jump of 0.164" and from my Hornady instruction manual the ideal jump is only .020 to .040. So I'm not even close.

The problem is, if I do load with a shorter jump then I'm no where near the cannelure.

So should I ignore the cannelure, or ignore the giant jump the bullet has to take to the rifling?

308_Ogive_zps33cdacbc.jpg


This is what the cartridge would look like with zero jump or jam.

Thanks in advance for any advise.
 
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Bart B.

New member
As long as the bullet's held well by the case neck, it doen'st matter where the bullet's cannleure is. What you show looks good to me.

'Tis the same thing with an uncannelured bullet; they don't know where they are in the case neck and typically shoot more accurate when seated with not much clearance to the lands. As long as they feed from the magaaine OK, use them. If too long for the magazine, reseat the bullets do rounds are about 1/16th inch shorter than magazine length.

"Perfect cartridges" don't have and dimensional specs. Semiatuo M1 and M14 match grade rifles rebuilt by the services would shoot good lots of commercial .308 Win match ammo into 4 inches at 600 yards with 1/10th inch bullet jump to the rifling.
 
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Ifishsum

New member
The cannelure means nothing unless you plan to crimp the mouth into it. All of my hunting loads look similar to yours, although usually a little deeper to fit into the magazine. I honestly haven't found bullet jump to be much of a factor with most typical bullet shapes, and not worth fretting too much about.
 
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243winxb

New member
Ignore the cannelure & giant jump. Start with the bullets base at the neck shoulder junction. Not the boatail , the full diameter of the bullets base. The COL should fit the magazine. Make adjustments if to long.
 
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tangolima

New member
I'm loading Hornady 165gr BTSP Interlock bullets #3045. My first batch I loaded according to my Hornady loading manual. With this spec I have an OAL of 2.750. At this length the ogive measures 2.159.

From my measurements the ogive touches the lands at 2.323 so at the depth I loaded these rounds I have a jump of 0.164" and from my Hornady instruction manual the ideal jump is only .020 to .040. So I'm not even close.
Click to expand...

I had the same dilemma with .30-06.

In your case, you have OAL 2.75". The max OAL for .308 win is 2.81". Your round may not fit in the magazine if you make it any longer. That means the best you can do is a bullet jump of .104".

My conclusion is that the ideal jump of .02" to .04" is usually not practical, unless you are shooting bench rest in single-shot manner. My approach is seat the bullet to max. OAL, if the neck has enough purchase on the projectile. One caliber or more is nice, but I will take 2/3, i.e. 0.2" for .30 cal bullets.

The picture you were showing, I doubt you have enough neck around that bullet.

-TL
 
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nemesiss45

New member
Are you target shooting or hunting? I have a 700 sps varmint In .308, and I only use it at the range, but my reloads never fit my mag. I have no need for rounds in the mag. If you are hunting, sure seat them to fit the mag... but if you can deal with it, the longer bullet will probably be more accurate.
 
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Jimro

New member
I've got a brand new Rem 700 in .308 Win and I'm trying to make the perfect cartridge.
Click to expand...

Remington has been known to have generous throats in their factory chambers. This isn't a bad thing, it means that the rifle can handle a variety of bullet weights and charges without developing an overpressure event.

I think you should start out by loading to the cannelure, and see if accuracy is acceptable. If you are going to start "chasing one ragged hole" you probably shouldn't do it with a factory rifle and a factory chamber with a 1:10 twist barrel pushing hunting bullets.

Jimro
 
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ocharry

New member
i might have a dumb question here but here goes

have you shot any of the bullets loaded to the cannelure?? you know your rifle just might like the bullet there,,,,just saying

why don't you load 5 and give them a try,,and then bump the bullet out .020 and load 5 and try that,,and then bump the bullet out another .020 and try another 5

i guess what i'm saying is if you haven't tried any of these you are just guessing anyway

every barrel and every chamber are individuals,,everyone will like something different,,,some may be close to each other with load preference,,,and you or i may or may not be able to see the difference,,,BUT there is and it will show up if you are really looking

my .02

ocharry
 
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