.308 load data question.

[Sitting Duck]

I have a Lyman 49 that I'm pulling data from and under the .308 section the diagram at the beginning shows an OAL of 2.810. The OAL under the .308 load data for the 168 gr. HPBT shows an OAL of 2.775. Assuming I'm not playing around with bullet setting depths, which I'm not, which one do I use?

I am loading up 168 Amax, with Varget, and will be using the min. of 41 and a max. of 45.7+ Sierra HPBT 168 data information. I will stop at 44 gr. or sooner if I find something she likes. Do you seasoned hand-loaders rely on the load data from the powder manufacturers or the data from the bullet manufacturers? I want to purchase the manuals that make the most sense for hand loading not just purchasing manuals for the sake of having manuals.

If I'm missing something using the Sierra 168 HPBT/Varget data for the 168 Amax, please let me know.

[darkker]

You are missing some pretty fundamental basics of reloading.
The OAL on the drawing from page 219, is the SAAMI max length. The 2.775" listed on the next page is the length actually tested at. If you aren't going to test the throat length of your specific rifle, you use the number which is specific to the bullet.
The length and shapes of the SMK and the A-Max, ARE NOT the same. So your distance to the lands will also not be the same. Because the construction, and the jacket material are different, the pressures will also be different.
Just because something weighs the same doesn't mean it is the same thing. Spend some time reading the loading information in the Lyman manual BEFORE you go to the load data, this is covered in that info...

You will also find that unless you have a specific reason to run max speed, the more accurate loads are generally near the lower end of the velocity range.

[scope eye]

Let me add that powders vary from batch to batch, then factor in every chamber which is unique in what it's max pressure is, so wether it is powder or bullet MFG, I would use the min load as a base line and go from there.

Dean

[Sitting Duck]

Thanks, for clearing up the diagram dimensions as being a maximum. I just finished 25 cartridges at 2.8 OAL.

I understand loading from the minimum, which is what I'll do. The 25 I loaded were 42, 42.5, 43, 43.5, and 44 grains of Varget. Hopefully, I won't run into any trouble with these starting at the bottom.

Thanks, for the replies.

[scope eye]

I would be very surprised if you got into trouble with those loads, get back to the forum with your findings so others can benefit from it.

Dean

[missed]

My .308 does not like 44g of Varget with the 168g AMAX. The AMAX length varies considerably with the polymer tip. I got my powder charges from the powder manufacturer. Having the Hornady lock and load chamber gauge and the bullet comparator is a very useful tool to determine seating depths and chamber lengths.

[missed]

I ran out and looked at my book,

I'm loading 42.5g of Varget, 43 had pretty flat primers and 43.5 I had to persuade the bolt open. 2.800 should put you about 0.020 off the rifling with the AMAX and about 0.010 with the SMK both 168g I have a 24" barrel FLCP-K.

[Dennis]

then factor in every chamber which is unique in what it's max pressure is

+ 1

[stangfish]

....and then there are conditions of the components.

[scope eye]

Nothing a little freebore wouldn't take care of. LOL

Dean