30-06 Tikka T3 Lite Loading

[MajorSpittle]

I am new to reloading and looking to work up my first rounds for my 30-06.

My first load will be a 208 Amax.

I have found my Tikka T3 lite shoots very accurate with both Hornady Superperformance and Federal Fusions in 150gr.

So I measured the Ogive on these rounds and they are both 2.591". So I figure this is where I will want to start for the Ogive length on the 208 Amax and see if it carries over for accuracy, but if I do this it will put the 208 Amax .12" off the lands and give me COAL of 3.325"?????

Something just doesn't seem to add up. I have measured the distance to Lands in my rifle with both the 208 Amax and 168 Amax and I get different numbers. 168 Amax gives me an Ogive length of 2.683" and the 208 Amax 2.711". I do not understand why the distance would be different with different rounds if I am measuring from the base of the Cartridge to the Lands in both instances.

Can someone please help me understand where my thought process is wrong?

Also of note: With the 208 Amax out to the lands I get a COAL of 3.445 but the max COAL the magazine in my rifle will take is ~ 3.375. Thus no matter what I will have to load the round at least .07 off of the lands. So how far off the Lands is too far?

Thanks for any help.

 

[RT2506]

I have not shot either of those A-Max bullets before but your OAL problem may be because the bullets have different ogive shape even though they are made by the same company. I have shot the 155 A-Max and it likes to jump between 20 & 10 thousands in my 7.5x55 Swiss K-31 rifle. I usually start 10 thousands off the lands and work back to fine tune. If you intend to shoot from the magazine I would start at max mag length and do a ladder test of loads with one of the 4350s powders and find my most accurate load then fool with seating depth loading further off the lands. In my experience the 4350s usually shoot very well with 180+ gr bullets in the 06.

 

[Trnelson]

RT2506 is correct. The bullets have a different nose shape. Ive seen both the 168 and 208 take deer ethically out to 680yards from my best friends 24" GAP 10. Are there other bullets that could be a viable choice, sure, but that is for another thread. He loads to 2.770" OAL with the 168 and 2.778" OAL with the 208. They feed reliably from his magpul magazines and shoot .6MOA all day every day. I don't know exactly where he is in terms of CBTO. He knows how CBTO and OAl relate in his rifle and found best accuracy with that CBTO. What I'm getting at in a rather long-winded fashion is that both of those bullets can shoot well with a jump to the rifling. So you should be able to find a CBTO that will feed through your rifle and shoot well, or you can seat them long and single feed them. It really comes down to what and where your rifle digs that bullet and what you want to deal with.

 

[howco]

Work with the 208 at magazine length for tikka, then see what powder charge gets the accuracy you are after. Both posters are spot on with ogive, if hunting with rifle I can't see loading as a single shot.

 

[ohiohunter]

Here is why it does not work, the ogive tool you use is not identical to your barrel. Though you have the same length relative to your tool, you do not have the same length relative to your bore. The angle of the bullet from tip to ogive is changing from one bullet to the next [style], so measuring to the lands must be done per bullet. Trust me, I wish it were a one and done deal.

 

[MajorSpittle]

Thanks for all the replies.