Could use some advice on load development on new 308

[Joshboyfutre]

I'm developing load for a new rifle I bought it shoots really good.
Rifle is Savage 10 fcp-sr w/brake 24" 1:10 twist barrel
Loads are 175g smk/IMR 4064/lupua brass.
I have two nodes, one that is 41 grain that shoots 2560 fps in 85deg weather and another that's 43.5g (no chrono)but is showing some signs of pressure. Bolt is a little stiff w/ejector Mark's here and there.
I'm wanting to develop a load that I can shoot it a hundred yards or long-range (hopefully). I'm not sure if the low node is fast enough to go out to 1,000yds and don't want to push my rifle to hard with the high node.
Any thoughts?
Still need to tweak the loads a bit for accuracy this is just from initial testing

 

[LocoGringo]

That 2560 will get you to 1000, but it'll be dropping quite a bit. I've got a Savage 10FP with a 24" barrel and I was getting the 175 SMK to 2690 fps with Varget and not having ANY difficulty lifting the bolt. I was going for 2700 fps from the 24" barrel, so I'm happy.

I don't understand what you mean when you say you have 2 nodes, but still need to tweak for accuracy. If it's a node, it should be fairly obvious that it's accurate. Also, is there a reason you're stuck on IMR 4064?

 

[jmr40]

My load data says 45.6 gr is a max load @ a little over 2700 fps. The 41 gr load is below suggested starting levels and should be less than 2500 fps.

How do you KNOW you're getting 2560 without a chronograph? When you start working near max loads I think a chronograph is necessary. It is the best way to prevent an over pressure situation. Trying to read conventional signs is not a good idea. But at this point even your heavier load is still well below max. I'd feel a lot better shooting the 2nd load over a chronograph so I'm not working blind. If that load is close to 2700 fps then you are close to max in your rifle even with only 43.5 gr powder.

I can't give much advice about shooting at 1000 but in theory 2560 with that bullet will just barely get you that far. I have shot some out as far as 600 and I've used 4064, but prefer Varget. 4046 has a reputation for excellent accuracy, and with max loads is slightly faster than Varget. I can't complain about the accuracy I've gotten with 4064, but I prefer Varget simply because it is not affected as much by temperature extremes. Which can be something to consider in hot or cold weather.

 

[Joshboyfutre]

- I have a chronograph and 2560 was the average of 10 rnd. By (no chrono) I meant I dont have that info as I have yet to measure the speed. I figure 43.5 out of a 24" barrel should get to 1000yds ok.
- What I meant by 2 nodes but need tweaked is that I only adjusted by .5 grain increments now from 41.0 and 43.5 I will go up & down by .2 grain to see If I can get closer to the middle of the node in the temp at the time.
- Hornady load data only goes up to 41.3, Nosler starts at 40.0 and goes to 44.0, Sierra only goes up to 42.8. My point being that there really isn't a "standard". Each company publishes different min-max
- I'm not necessarily stuck on IMR 4064 I'm simply trying to figure out what the best load for 175 smk with IMR 4064 is. Next I'll use varget w/smk, then I'll do 4064 w/ Berger vld, then varget. I have to admit I do prefer 4064 as it seems to be a little better accuracy wise for 308.
Thank you for the concern

 

[LocoGringo]

The Hodgden website says the max load is 45.6C for a 175 grain bullet and IMR 4064 pushing 2728 fps. By that website, you're nowhere close to max with your 43.5 grain load. The data provided is straight from the manufacturer. I'd trust that data the most.

http://www.hodgdonreloading.com/data/rifle

I understand that Hornady is very conservative with their load data, the rest, I don't know.

 

[RussellC]

You might want to check this thread out.

https://www.thehighroad.org/index.php?threads/308-long-range-load-development-results.822638/

Russellc