Start load development at SAAMI OAL? (308, 168, 4064)

[Metal God]

The 168gr Fed GMM is in fact loaded with 43.3 to 43.5gr IMR 4064 . Not going into how I know this , way to long and complex .

As for seating depth . The first thing you need to do with any bullet that you may be able to load at or in the lands is to figure out at what COAL length the bullet touches the lands . There are multiple ways of doing this from using the Hornady gauge to just using a fired case and very lightly crimping the neck to just hold the bullet . You then seat the bullet very long in the case . You now chamber that round and when the bullet hit the lands it's pushed back into the case . Carefully extract the round and measure . That method does take a bit of getting used to and if done wrong can result in very inconsistent COAL .

Generally if you plan to adjust seating depth later to fine tune your load . You will want to start with the cartridge as long as you can have and still function in the firearm in the way you intend . Meaning if you plan to load from the mag . Then the COAL can not exceed the ability to fit in the mag . The point of loading long or at the lands to start with is if the load you later want to adjust seating depth with is at max pressure . You can only adjust seating depth away from the lands which should be safe to do with a max pressure load . If you do it the other way around and start way off the lands and you end up with a max pressure load . Adjusting the seating depth closer and closer to the lands can easily send your pressures way over max .

If you are new to this type of fine tune loading I recommend finding your MAX COAL then back off the lands .020 and start loading there . Once you have more experience and understanding with this type of loading . You can start using some of the more advanced methods to fine tune the load

[blockfort]

The 168gr Fed GMM is in fact loaded with 43.3 to 43.5gr IMR 4064 . Not going into how I know this , way to long and complex .

Everyone seems to say it is 4064, and I personally measured 43.3/43.4 grains, though I have seen other numbers in places.

[JMP]

Everyone seems to say it is 4064, and I personally measured 43.3/43.4 grains, though I have seen other numbers in places.

That's what I have heard too. Really, all you need to know is Varget or 4064 for 168s. I'd not touch anything else; most people prefer Varget. I started with Varget, but I moved to 4064 when Varget was super hard to find, and I actually got better results (same accuracy, but a few more FPS).

[blockfort]

That's what I have heard too. Really, all you need to know is Varget or 4064 for 168s. I'd not touch anything else; most people prefer Varget. I started with Varget, but I moved to 4064 when Varget was super hard to find, and I actually got better results (same accuracy, but a few more FPS).

I have a ton of h4895, what's that good for? I have lots of 155smk, and a small box of 190's to test

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[LynnJr]

You can use H4895 or RE15 and get great results with the 168's.
On the seating depth if you are working up your load go as long as you can go.
After you get a powder charge that works all you have to do is adjust your seating depth in one direction only.
Powder has the biggest influence on your guns accuracy and seating depth is the second most important part of accuracy.

[Victor Cachat]

Every one of my chambers but one is more than 0.1" over SAAMI spec. and magazine length is as far as I can go, unless I want to feed the rounds by hand.

I would concentrate on the powder load first.

And my .308s all like ~41gr of 4064

[blockfort]

Sort of an update here.