Horizontal in load development

[the big greasy]

.010 is a coarse test or .003 for a fine test when you are getting close

What is the shortest one should go down from 2.800

 

[338 dude]

While seating the bullet deeper you do reduce case capacity with the same charge it would raise pressures but .010 will not do much of anything to pressure you'll have to move a fairly large amount to see pressure signs

 

[LongBomber]

You can go a long ways, not sure how far your 2.8" is off the lands already, but I have jumped bullets as far as .150"
You should be able to go all the way to 2.7 or shorter if needed.

What is the shortest one should go down from 2.800

 

[Mikecr]

What does back away from powder node mean? My node is 41-42 grains

Powder nodes and best seating are independent of each other.
With seating testing, you want to see SEATING AFFECTS alone, and not also seating affects to powder.
Ideally you would do seating testing at worst powder charge that you're aware of, while having margin for pressure.
You could drop down to ~38-39gr, which should take you well away from your powder node.
If you don't do this, it will not take a lot of seating adjustment before your powder node collapses, making seating adjustments 'appear' to be a detriment. Then you couldn't tell actual good from actual bad.
If you back off from a powder node, grouping will be larger but that's ok. You will easily see this larger group open and close with seating adjustments. Just pick the tightest of seating regardless of overall group size.

After full seating testing, work back up in powder to a node (which could now be a bit different) while at best tested coarse seating.
Once back into powder node fine tweak seating +/- in it's window for tightest group shaping. This will be a narrow window that is a desired summation of everything.

 

[Bravo 4]

Depending on your particulars (velocity, baro, temp, etc) you should be getting 1" or more per mph of wind at 500, just saying. Any variation of the wind that isn't compensated for and you may have part of your "problem". Add that to the existing horizontal of your groups, sprinkle in a little shooter induced error, and voila things can get wonky quick.
You are still under MOA.

 

[Alex Wheeler]

Seating depth and powder charge can give horizontal. Its barrel harmonics. Some powders seem to create more of a horizontal harmonic than others, RL33 comes to mind. If you cant tune it out with powder charge or seating depth switch to a different powder. Like powder charge, seating depth will have multiple "nodes". You will find multiple places it will tune up. I much prefer to find a good powder charge first, then test seating. When your way off on powder charge it can be difficult to get anything to shoot well enough to pick a winner.
The most important part of tuning is starting with the right components for the barrel. Try a few different powders right off the bat, one usually stands out. I'd rather have a little vertical in my tune than horizontal. At least the vertical will help you cut the wind a little.

 

[oneeyejohn]

Their is a good article on the Burger Bullets website about bullet jump. The article was wwritten by Eric Stecker. Bullet Smith with Burger. It was posted 4/8/09. Their is also a good write up on PrecisionRifleBlog.com titled Ammo & Handloading, Load Development dated 11/29/20.

 

[Lefty G-gear]

So 308 175mk 41-42 grs of imr 4064, coal 2.800. At 500 yards the vertical is 1-1/4 inch spread, that's the best node, but my horizontal is 3-4 inches. So I'm still doing load development, but I'm wondering will shortening coal help horizontal dispersion? I can't go longer due to mag length. Also what's a good increment to decrease at a time?

What kind of scope are you shooting with?
Does it have a side-focus? or adjustable objective?
If not, then the parallax is set for 100-yards or so.
That may be the issue: parallax.
We want the scope focused on the target.

Understanding Scope Parallax - Black Flag Armory | Medford OR

What is parallax, why do we care, and how do we correct parallax errors when shooting? We can clear up those questions in plain English here.

www.blackflagarms.com

 

[Lefty G-gear]

What kind of scope are you shooting with?
Does it have a side-focus? or adjustable objective?
If not, then the parallax is set for 100-yards or so.
That may be the issue: parallax.
We want the scope focused on the target.

Understanding Scope Parallax - Black Flag Armory | Medford OR

What is parallax, why do we care, and how do we correct parallax errors when shooting? We can clear up those questions in plain English here.

www.blackflagarms.com

I just ordered one of these a few minutes ago.

https://www.amazon.com/gp/product/B00794LIEM/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

 

[the big greasy]

What kind of scope are you shooting with?
Does it have a side-focus? or adjustable objective?
If not, then the parallax is set for 100-yards or so.
That may be the issue: parallax.
We want the scope focused on the target.

It's a nightforce 5.5-22-56, is there a better way to get paralax adjusted other than moving your head until the crosshairs stop moving on the target? I thought I got it adjusted out to no movement but it's hard

Understanding Scope Parallax - Black Flag Armory | Medford OR

What is parallax, why do we care, and how do we correct parallax errors when shooting? We can clear up those questions in plain English here.

www.blackflagarms.com

 

[fisherman987]

Powder nodes and best seating are independent of each other.
With seating testing, you want to see SEATING AFFECTS alone, and not also seating affects to powder.
Ideally you would do seating testing at worst powder charge that you're aware of, while having margin for pressure.
You could drop down to ~38-39gr, which should take you well away from your powder node.
If you don't do this, it will not take a lot of seating adjustment before your powder node collapses, making seating adjustments 'appear' to be a detriment. Then you couldn't tell actual good from actual bad.
If you back off from a powder node, grouping will be larger but that's ok. You will easily see this larger group open and close with seating adjustments. Just pick the tightest of seating regardless of overall group size.

After full seating testing, work back up in powder to a node (which could now be a bit different) while at best tested coarse seating.
Once back into powder node fine tweak seating +/- in it's window for tightest group shaping. This will be a narrow window that is a desired summation of everything.

Very nice explanation!

 

[Lefty G-gear]

I got one of these too, but yet to put it together.

Amazon.com : Caldwell Lead Sled DFT 2 Adjustable Ambidextrous Recoil Reducing Rifle Shooting Rest for Outdoor Range : Sports & Outdoors

Amazon.com : Caldwell Lead Sled DFT 2 Adjustable Ambidextrous Recoil Reducing Rifle Shooting Rest for Outdoor Range : Sports & Outdoors

www.amazon.com

Video

 

[PNWdude67]

So 308 175mk 41-42 grs of imr 4064, coal 2.800. At 500 yards the vertical is 1-1/4 inch spread, that's the best node, but my horizontal is 3-4 inches. So I'm still doing load development, but I'm wondering will shortening coal help horizontal dispersion? I can't go longer due to mag length. Also what's a good increment to decrease at a time?

Save your component and call it good. Sub 3/4 MOA dispersion at 500 is not sub-optimal performance. Merry X-mas

 

[entoptics]

The longest I can go is 2.800, because I do want to use the box mag, what increments should I work backwards?

I will admit there was a slight wind, although I didn't think it was a factor because it was light, maybe not lol

Another use for the MERC Tool. Here's the expected deviation at 500 yds with a 0.25 MOA shooter/rifle combo, with 5 fps velocity SD, and 1 ± 0.5 mph head wind (so dead calm to "slight wind") that's switching back and forth from NE to NW in direction.

Looks like what you describe. Twice as wide as it is tall...

IMO, you're doing pretty good to get sub MOA dispersion at 500 yds. It doesn't take much wind uncertainty to get horizontal stringing...