For my 74 Yr old buddy who hunts from a ladder chair...Shots at whitetail under 100 yds....

Kinda hoping for something around 2800 FPS with a 150 interlock.

Most book start loads I see are showing around 3000....guessing some of these loads might actually chrono slower than that?

Whatcha got?

Check out the start loads on the left side of the page.

I appreciate the time it took to put that together but those loads still seem towards 3000 fps.
I stumbled onto page of Sierra data on 165 that looked pretty mild.....(2700fps)... any chance somebody has the page on the 150s?

Here is a page from Hornady and Sierra

Thank you very much....I'm liking those 4895, varget, 4064 loads!

You could just linearly interpolate to slightly reduce the loads if you're shooting for 2700 fps. Over a short interval, shouldn't be too far off nor in dangerous territory either.

Thanks much guys... I had amazing luck personally finding a lyman start load in my 300 Win Mag with i4320....thing is an amazing tack driver all the way to 300....loafs at 2800.... and kicks like a 308.

I'm thinking if I can get the same results with his 300 WSM I'll be able to extend his hunting career nicely.

You are really not trying to reduce the velocity that much, and I can not imagine getting into trouble with most any powder you want to use.

I do a lot of this stuff myself, and like to use faster powders like 3031 or 4064 for this work.

But H4895 is the all time favorite for reduced loads, with recomendations for such from the manufacturer. As per Hogdgon, H4895 may be safely reduced to 60% of max.

Interpolating from the Lee manual shown above: 48 to 49 gr H4895 should put you to 2800 fps with a 150. According to the Sierra, 52.8 gr H4895 will do the same thing. You will never know exactly where you need to be until you run a few loads over the chronograph.

Personally, I would consider going all the way down to 2600 fps for my freind if shots were not going to be over a couple hundred yds.

http://load-data.nosler.com/nosler-load-data/pdf/300-winchester-short-magnum/300-WSM-150gr.pdf

When I had a 300 WSM I had good success with RL 15 and 150's and 165's. Speed will probably be less than what Nosler states, at least that is what I found. Even the max loads of RL 15 (150's @ 3100 fps + and 165's @ 3020-3050 depending on exact bullet) kicked a lot less than full power loads of H 4831 sc and 180 gr bullets. Other similar powders could give you similar results.