Hi guys. I am at a loss. Alliant lists 49gr. MAX for 150gr bullet, Sierra lists 44.8 for 150gr pro hunter. Why so much difference. New powder and new bullet for me. Were to start? Do any of you use this combo?

I do NOT use this combination, I use 165s in the .308 Win.

But Steve's Pages, and an old Speer manual (#12) both show max load with RL-15 and 150 gr bullets at 49.0 grains. Hodgdon's 26 shows max at 47.0 grains.

As I know 42.5 is OK with 165s in my rifle with 165s ... I'd start at no more than 44.5 and work up. A big mistake is just too costly to start too high!

the diff comes from primer brisance.
case volumne.
and the bearing length and jacket thickness of the bullets.
the main reasons i don't like lee's loading data books.

try 45.0 grs of RL-15 with the 150s.. I do with the sierra, speer & bil.tip. shoots .750" at 100 yards. my NOSLER #3 list 46 max.

I've used up to 46 grains Re-15 with 150s in the .308 WCF, but best accuracy generally seems to fall around 45 to 45.5 grains.

Bullets used were Noslers BTs and ABs, Hornady SSTs and Sierra's Pro Hunter spitzer and GameKing -- and all used Fed 210s.

I was asking a similar question recently and was also a bit bemused by the large range of max loads.

I am loading 150 grain Hornady spire points in Lapua cases with CCI primers and a COL of 2.735. I started at 41 grains and worked up in .5 grain increments to 46 grains with 46.2 being listed as max in my Lyman manual. I saw no pressure signs but think that 44.5 grains will probably be the most accurate. I need to load up a pile of them now and give them a good testing.

Vines, who posted earlier in the thread, was able to tell me that I was probably getting decent velocity at 44.5.

Hope this helps a little.

I would say that whatever the MAX listed is, it doesn't really matter. The starting points are far more important.
Every gun is individual and will show pressure accordingly. Your gun may show pressure signs mid way through the listed charge amounts, or may go two grains above. At the range a couple days ago, there was a guy with a .308 Kimber. His rifle was showing some pretty flattened primers with factory loads.

The point is to ALWAYS start low and work your way up. As has been said before, the most accurate loads are usually somewhere in between. In fact, most of my rifle do not like hot loads, which is fine with me.

You need to work up the load for YOUR rifle.

I've gone to 47.0 gr with the 150 partition gold moly-free and the TSX.

Start at 44.o or 45.o gr and go from there.

WOA, my Alliant guide shows 46.3 grains of RE15 as max for the 150 bullet. Which version are you looking at? I usually avoid the "one-offs" that have higher than most listings. The only manual that I have seen that listed 49 grains was an OLD Speer manual from like the 70s or 80s, I forget.

I load 45.5 grains with the Hornady 150 and Partition with great accuracy. If you start low and work up, you will probably end up the same place.

Been working with this powder on my wife's .308 and 180 gr Paritions. Have loaded up to 44 grains without any pressure signs but early evidence suggests the rifle likes 42 grains.

With 168 smk and 175 smk bullets I have had great luck with 44 gr. of RL 15 and a Federal 210. These loads shoot great out of a 5R Remington I have been working with this past year.

Speer also show 49gr, Hornady less and Nosler much less (memory fails) I've loaded to 47.5gr and left it at that despite so so MV (2,725fps)

Quite a disparity in Varget max loads too.