Bullet CBTO

[jwfire25]

Hi guys,

I'm reloading for my .308 Bergara HMR. I'm measuring the ogive for the rifle but I am getting different measurements for different bullets. I understand there will be slight differences between bullet grains, manufacturer, etc.

I'm curious as to what is a normal variance?

SMK 168 and 175 grain measure 2.271

Nosler Ballistic Tip 165 grain measures. 2.291

Is a variance of .020 normal? Seems extreme to me but I'm curious on your guys thoughts. I just want to make sure im not missing something. Same OAL gauge and comparator was used.

Thanks in advance.

John

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[FLIGHT762]

Yes, different bullets, different measurements. Not unusual at all.

[jwfire25]

Yes, different bullets, different measurements. Not unusual at all.

Awesome thank you.

Along those lines do you guys worry about OAL at all? What if the OAL is of SAAMI maximum specs?

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[baih777]

You also have to be careful with OAL.
For 308. You can load your bullet to the ogive and it might be to long for the magazine.

But write down and save all your info.

[jwfire25]

You also have to be careful with OAL.
For 308. You can load your bullet to the ogive and it might be to long for the magazine.

But write down and save all your info.

Yes sir the rounds fit in my magazines. I'm starting .010 off of the lands

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[ar15barrels]

Yes sir the rounds fit in my magazines.
I'm starting .010 off of the lands

You can get to within 0.010" of the lands AND fit your ammo in the mag on a factory barrel 308?
That's amazing.

[jwfire25]

You can get to within 0.010" of the lands AND fit your ammo in the mag on a factory barrel 308?
That's amazing.

With the SMK's. I am running 2.260 CBTO which gives a OAL of 2.841-2.843. I am using magpul AICS mags. I haven't loaded up the Noslers yet which will be longer. Might be pushing it with that bullet

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