Load developement for using the Satterlee method

[9rcrazy]

Hi All,

I am looking to come up with a solid load for my 6.5 creedmoor. It has a 26 inch tube with 1-7.5 twist. Berger 140 hybrids, H4350, Lapua brass and a CBTO of 2.0920.

In an effort to save time, $, and barrel life; I tried the Scott Satterlee method. Here are the results....

I think it shows the velocity curve, but I am not sure where the best node would be.

Your thoughts, suggestions are welcome.

Thanks, Mike

 

[MikeMcCasland]

41GR.

That's a well established load with the components you're using, and it's clear as day 41 is in the middle of your node based on your testing.

Load at 41gr on the dot, and do your depth testing from .005 off, working back in .005" increments. You'll probably find a depth that one holes them.

Your velocities look a little low, but if this is early in the barrel life, it'll probably speed up 50-75fps pretty soon.

Edit: Mine tuned in right at .028 off the lands with the 140 Hybrid. 2840 FPS out of a 30" Bartlein with the SAAMI/.199fb reamer.

 

[9rcrazy]

Thanks Mike. The barrel has about 350 rounds down it. What about 41.8 and 42.0, is that another node? Velocity is better.

 

[MikeMcCasland]

If it were me, I'd find the velocity to be too high to trust it to remain stable in all temp conditions. I know guys will swear up and down that they're getting 2900fps with whatever 140 class bullet, but in my experience the consistent sweet spot is the high 2700s/low 2800s with the longer barrels. Much more stable in all conditions.

I spent 2-3 minutes looking for a specific post over on the AS forums, but couldn't find it; Frank Green (Bartlein) basically says the same thing.

I'd do your depth testing at 41gr. Once you find your optimal depth, then go load up 10 using that measurement at 41.8 if you really want to know what you're missing, and shoot them at 200-300 yards to see differences at a higher resolution.

My 2c.

 

[9rcrazy]

Copy, thanks.

 

[Namekagon]

Can you describe this method? I think I can assume whats going on, but I've never seen this described before. Is there another thread I should read?

 

[9rcrazy]

The 65 guys did a video with Scott Satterlee describing the method. On You Tube ,
S4 - 04 - 10 Round Load Development Ladder Test

 

[Deleted member 113831]

This is not purely a Satterlee test as you have done it. A Satterlee test is primarily based on velocity. The position of the shot in relation to others in the set isn't taken into account.

You have combined the one shot per charge of the Satterlee method with the target based OCW method. If someone insists on doing one shot per charge, then the way you have done it is the best possible way IMO.

I experimented with the same thing a year or so ago in 308:


BTW, I also vote for 41 grains.

 

[Dthomas3523]

Make sure 38.8 41.0 41.2 have a good ES.

If so, do a seating depth test on 41.0 to find your seating node, load on the long end of it to be more forgiving for throat erosion, and go.

 

[Steel head]

I still use the satterlee test but I shoot two of every charge instead.

 

[jaybic]

I have also used the Satterlee test and found it to work but I have also seen posts that seem to discount it somewhat. I am all ears for a better way or perhaps a revised/refined verstion if anyone may care to share. thx....

 

[ditter]

I'd do three shots each. But youll probably find a sweet spot around 41.5 and another one 42.5. I do 41.4 and its gets me about 2805 fps.

 

[mkollman74]

41, maybe 41.9...

 

[Joeydias3]

I don’t worry about or take shot placement into consideration at first. Only gather the velocity data. If I have to I’ll shoot them into the dirt out my back door. Then either that data into a line graph generator. Here you can see the velocity flat spot between 37.4-37.8. The FPS only changed by 15 fps. Then I loaded 5 rounds at 37.6 to test extreme spread.

 

[A&8's]

I don’t worry about or take shot placement into consideration at first. Only gather the velocity data. If I have to I’ll shoot them into the dirt out my back door. Then either that data into a line graph generator. Here you can see the velocity flat spot between 37.4-37.8. The FPS only changed by 15 fps. Then I loaded 5 rounds at 37.6 to test extreme spread. View attachment 7385429

I'd do 5ea @ 37.5, 37.6 & 37.7. Shoot for groups at 200 or 300y and check ES and SD's. That is, of course, the best seat depth has already been established.

I, personally, stay away from charges that are going up/down in the previous or next charge.

 

[Dthomas3523]

Interesting observation. When we true our data, we typically look at velocity at 600 and in. And work with BC at 800+.

This exactly same philosophy should be applied to load development. If groups aren’t working inside 600, it’s typically the shooter or the velocity being inconsistent. If you have done your diligence with chrono and loading, your load will perform the same @ 100-600 or so. There’s nothing you can glean from 300 that you can’t at 100. Unless for some reason you feel like the larger groups make it easier for you to look at. Functionally, there is no difference.

Now, we look at the 800+. Once you know your velocity ( ES ) is stable, the only two things that can affect your group size at distance is the shooter, or the BC of the bullet varying too much from bullet to bullet. Loads don’t “fall apart” at distance. It’s either shooter, velocity, or bullet. At this stage you should have already eliminated the shooter and velocity. So, the bullet is your problem.

The only way to fix this is either sort/tip/trim bullets or buy higher quality bullets that are more consistent from bullet to bullet.

But shooting groups at 100, then again at mid range and then again at long range, is typically a waste of ammo in the intermediate ranges.

Now, if you shoot something like 600 F class and you’re tuning for positive compensation, that’s different. I’m speaking for load development for random distances.

 

[Joeydias3]

I'd do 5ea @ 37.5, 37.6 & 37.7. Shoot for groups at 200 or 300y and check ES and SD's. That is, of course, the best seat depth has already been established.

I, personally, stay away from charges that are going up/down in the previous or next charge.

Agreed. I always find the best load in the middle

 

[Joeydias3]

Interesting observation. When we true our data, we typically look at velocity at 600 and in. And work with BC at 800+.

This exactly same philosophy should be applied to load development. If groups aren’t working inside 600, it’s typically the shooter or the velocity being inconsistent. If you have done your diligence with chrono and loading, your load will perform the same @ 100-600 or so. There’s nothing you can glean from 300 that you can’t at 100. Unless for some reason you feel like the larger groups make it easier for you to look at. Functionally, there is no difference.

Now, we look at the 800+. Once you know your velocity ( ES ) is stable, the only two things that can affect your group size at distance is the shooter, or the BC of the bullet varying too much from bullet to bullet. Loads don’t “fall apart” at distance. It’s either shooter, velocity, or bullet. At this stage you should have already eliminated the shooter and velocity. So, the bullet is your problem.

The only way to fix this is either sort/tip/trim bullets or buy higher quality bullets that are more consistent from bullet to bullet.

But shooting groups at 100, then again at mid range and then again at long range, is typically a waste of ammo in the intermediate ranges.

Now, if you shoot something like 600 F class and you’re tuning for positive compensation, that’s different. I’m speaking for load development for random distances.

this is the first group I shot pass 100 with that load. Went right to 785 yards. I was very happy with it!

 

[Dthomas3523]

View attachment 7385517
this is the first group I shot pass 100 with that load. Went right to 785 yards. I was very happy with it!

As long as velocity is consistent and bullet BC is consistent, if it does well @100, it will do well at distance. There’s nothing else besides the shooter that can change that.