Horizontal in load development

[the big greasy]

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?

 

[Lionel Boyd Johnson]

I'll assume that you're asking a serious question here, so my serious answer is wind may be a more significant factor in horizontal group spread. Merry Christmas, Ed

 

[jsthntn247]

Go in towards the lands to decrease horizontal. Once you go to far in, vertical will increase.

 

[JMW67]

sounds like wind or trigger pull is it all in one direction from the point of aim

 

[Jud96]

Wind would be my first guess. I would either retest on a calm day or shoot groups at 100 yards. Your seating depth can be adjusted to change your group size and shape. Contrary to popular belief, seating bullets both closer and further from the lands can both negatively or positively affect your group sizes. I would suggest working forward in .005 increments until you reach your lands or your magazine restricts you or until you find a good load. If you don't get better results, then work back from 2.800" and see if that improves things. Be careful and don't seat the bullets too deep into the cases.

 

[the big greasy]

Wind would be my first guess. I would either retest on a calm day or shoot groups at 100 yards. Your seating depth can be adjusted to change your group size and shape. Contrary to popular belief, seating bullets both closer and further from the lands can both negatively or positively affect your group sizes. I would suggest working forward in .005 increments until you reach your lands or your magazine restricts you or until you find a good load. If you don't get better results, then work back from 2.800" and see if that improves things. Be careful and don't seat the bullets too deep into the cases.

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

 

[Mikecr]

The best you can do is Berger's recommended full seating testing.
Be sure to back away from your current load so that you can see results of seating instead of simple loss of powder node.

 

[Jud96]

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

Work back in .005 increments.

 

[the big greasy]

The best you can do is Berger's recommended full seating testing.
Be sure to back away from your current load so that you can see results of seating instead of simple loss of powder node.

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

 

[the big greasy]

Work back in .005 increments.

Ok will do, thanks!

 

[jsthntn247]

Jud 96 is correct working back is the only thing you can do if you can't go forward

 

[the big greasy]

Jud 96 is correct working back is the only thing you can do if you can't go forward

Ok, what would you guess to be the shortest one should go 2.800 being the max

 

[jsthntn247]

Wherever it shoots best

 

[338 dude]

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

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