Would you prefer a 1" vertical string group or a 1" horizontal string group?

[Les in Wyoming]

I did a search and could not find this particular topic. My Ruger m77 30-06 used to shoot sub MOA groups but somehow lost its accuracy. Started over and bedded it. My old load seems to be right, but have been chasing seating depth. Found a node. When the bullet is seated at 3.610 CBTO, it shoots a 1" horizontal group. This is OK for hunting, seeing I use my 300 WM for precision. But I am kind of spoiled with shooting a ragged hole at 100 yards. So I pushed the bullet down another .005 (3.605 CBTO). This shoots a vertical pattern 1". I was going to just leave well enough alone and load up a bunch. But . . . it nags at me. From what I understand, horizontal and vertical stringing are seating depth issues. Not sure which direction I should go. Whether to go for perfection or pick one or the other. Would appreciate any opinions. Thanks.

 

[L.Sherm]

Have you tried going closer to the lands?
Start at .005 off and work back .005 at a time and see what you come up with.

 

[OldElkHunter1961]

Realistically at any ethical range that I would use a .30-06 on big game a 1" vertical dispersion is essentially meaningless. Run the 1" separated trajectories through the shooters ballistic calculator on line with a 200 yard zero.

 

[WildRose]

Realistically at any ethical range that I would use a .30-06 on big game a 1" vertical dispersion is essentially meaningless. Run the 1" separated trajectories through the shooters ballistic calculator on line with a 200 yard zero.

Just a reminder, that's a taboo subject here.

 

[WildRose]

I did a search and could not find this particular topic. My Ruger m77 30-06 used to shoot sub MOA groups but somehow lost its accuracy. Started over and bedded it. My old load seems to be right, but have been chasing seating depth. Found a node. When the bullet is seated at 3.610 CBTO, it shoots a 1" horizontal group. This is OK for hunting, seeing I use my 300 WM for precision. But I am kind of spoiled with shooting a ragged hole at 100 yards. So I pushed the bullet down another .005 (3.605 CBTO). This shoots a vertical pattern 1". I was going to just leave well enough alone and load up a bunch. But . . . it nags at me. From what I understand, horizontal and vertical stringing are seating depth issues. Not sure which direction I should go. Whether to go for perfection or pick one or the other. Would appreciate any opinions. Thanks.

Have a gunsmith or someone else you know scope out the chamber and barrel. If it was a sub MOA shooter and suddenly ceased to be you have an issue that may or may not be easy to solve.

Windage errors tend to still amount to hitting your target unless severe, elevation errors can mean a complete miss high or low or result in crippling but not killing so if I had to pick one I'd rather I think live with the windage error.

Out to about 600yds that should still put one in the bread box for a clean, quick kill.

 

[OldElkHunter1961]

Just a reminder, that's a taboo subject here.

Ethics? We all set personal limits. I did state at any ethical range that I would shoot, thus taking personal responsibility for my self imposed limit, and not painting with a broad brush.

 

[Longtine88]

You want the same vertical. Horizontal generally is fixed by seating depths.

 

[tim_w]

That stringing can be seating depth or powder load, IME. Normally with the precession you are seeing I would increase jump another 0.003 or up powder a couple tenths.

My thought without knowing any other info is to try another 0.003 of jump (shorter COAL) and see if it does not tighten or change group dispersion. If it does I would go up in 0.003 till it starts to open up to see the size of the node. Then I would set the jump at the longest coal that was where it tightened up.

With that said info I would want to know is

How many rds down the barrel total?

What is the distance to the lands. At least within a few thou. Without reference to tge old load it's like starting over. What are the coal limits of the mag?

What was the prior tuned load jump distance when it was developed? Assuming same bullet powder primer. If using the same bullet I would start by finding that same jump distance, not the same coal, and then tune the powder node again. Usually a good bet is to look around the orginal loads vel for powder node.

Have you ensured there is not possibly a carbon ring? Bore scoped?

 

[Deputy819]

@OldElkHunter1961

Wildrose was referring to Forum Rule #1….

RULES

www.longrangehunting.com

 

[WildRose]

Ethics? We all set personal limits. I did state at any ethical range that I would shoot, thus taking personal responsibility for my self imposed limit, and not painting with a broad brush.

Just reminding you we do not discuss the ethics of hunting here at all. That's the one subject completely verbotten by Len.

 

[deadidarren]

Just about all my targets with a heartbeat are vertical so for those rifles prefer vertical spread as for rifles for the four-legged variety would prefer horizontal.

 

[Another Casual]

With regards to loss of accuracy, I'd check all the usual suspects. Clean barrel, no carbon ring, all screws torqued, etc. Does your Ruger have a pressure pad in the barrel channel? Some models with lighter barrels need it to shoot well and if you've removed it or bedded it in a way it no longer contacts the pad the accuracy may have changed due to that.

How many rounds are the groups? If each was a group of 3 I'd want more data. A 5 or even 10 shot group tells you a lot more.

 

[Bushersam]

Vertical is powder
Horizontal is seating depth

 

[Longtine88]

^^^^^