Long range load development at 100 yards.

[P3S]

Seating test with 37.4 and 37.5 grains of H4350. Although 37.5 produced the smallest (.070 @ .105) group, 37.4 produced more consistent groups. Should I continue with the seating test?

 

[P3S]

37.5 grains H4350

 

[Erik Cortina]

37.5 grains H4350

I'd go with .098" and load .5 gr. increments on each side of your powder charge and shoot groups to pinpoint node.

 

[savageshooter86]

I was thinking same because 0.098 shot small both powder charges

 

[P3S]

Mr Cortina- Looks like the pinpointed node is between 37.5 and 37.8 grains of H4350 with the 140gr Berger Hybrids.

 

[savageshooter86]

Good shooting. That's looking good. Maybe 37.6gr.

 

[P3S]

Thanks Andrew

 

[Erik Cortina]

Mr Cortina- Looks like the pinpointed node is between 37.5 and 37.8 grains of H4350 with the 140gr Berger Hybrids.

Yes, I agree. Now, make a note of what temperature this load was developed at and keep that in mind when loading for a match. You can load to the middle of your node most of the time, but if temperatures vary greatly from those at which load was developed, you can load towards the bottom or the top of the node. In the summer I would load at 37.5, and I would load at 37.8 in the winter. Make sense?

 

[Steve Blair]

In the summer I would load at 37.5, and I would load at 37.8 in the winter. Make sense?

[br]
I don't understand this winter and summer stuff with loads. Is it because the bullet will fall faster when the earth is tilted?

 

[Erik Cortina]

In the summer I would load at 37.5, and I would load at 37.8 in the winter. Make sense?

[br]
I don't understand this winter and summer stuff with loads. Is it because the bullet will fall faster when the earth is tilted?

That is correct Steve. ;D

 

[P3S]

Yes, it does make sense. I annotated the temperature on the target for future reference.

 

[TikkaSporter]

A couple quick questions... And I apologize if the answers were already covered earlier, as I could only make it through 25 pages of this thread before my eyes started getting stuck cross-eyed

- Are these test results valid if you change primers, but nothing else... Or do you have to throw them out altogether?
- Why do we only look at the vertical differences in the group centers? Do barrel harmonics only occur in the vertical plane?
- Do we also consider chronograph ES when looking at these?

I completed a test today... I'll put it up in a second for review. Hoping someone has some recommendations for me on where to go from here.

 

[Brians356]

- Why do we only look at the vertical differences in the group centers? Do barrel harmonics only occur in the vertical plane?

Speaking for myself, when working up loads in general, I ignore any cross winds, and don't attempt to hold off for wind. I concentrate my bench technique on holding consistent vertical. And since the process described herein keys on changes in vertical displacement, for my part it doesn't make sense to consider horizontal displacement or spread.

 

[TikkaSporter]

Here's my 100 yard long range load work up test...

Rifle:
260 Remington
Defiance Deviant Hunter action
Bartlein barrel, 22", 3B contour, 1:8.2 twist, no brake, 46 rounds at start of test
Manners T1 100% carbon fiber stock
Chambered and bedded by GAP

Conditions:
6200 ft elevation
29.9 Baro pressure
62 F avg temperature
19.5% humidity
Sunny, no clouds
Started at about 9:30 am... Ended around 11:15 am
Wind less than 5mph until last two groups, where it went up to about 10-12 mph

Loads:
H4350 powder
140 gr Berger Hybrids
Lapua Brass
Federal 210M primers
39.0 - 42.2 gr in 0.4 gr increments (1%)
2.880" COAL = 0.020" jump to lands
- Virgin brass, sorted and prepped, expanded in mandrel, then FL sized for uniform neck tension equivalent to final loads

Notes:
- Each shot was chronographed with a CED Millennium II... Not sure if I'm trusting the ES that I was seeing for this.... Bad, bad, bad


Here's a pic of the raw target:

And here it is after being analyzed with the OnTarget Software - vertical distance from POA and chronograph data added:

 

[Erik Cortina]

- Are these test results valid if you change primers, but nothing else... Or do you have to throw them out altogether?

Added to the original post on this thread.
Update 3/29/15
A step I have added lately to my process is to do the powder charge test with multiple primers to see which one shows best potential as well as more consistent chronograph numbers. The primers that performs best during the powder charge testing is the one that I will do the seating depth testing with.

- Why do we only look at the vertical differences in the group centers? Do barrel harmonics only occur in the vertical plane?

Harmonics do not only occur in the vertical plane, however, we are only looking for a place where the groups coincide, and vertically is the easiest place to tell since wind would influence horizontal movement of groups.

- Do we also consider chronograph ES when looking at these?

Yes.

 

[Erik Cortina]

Here's my 100 yard long range load work up test...

Rifle:
260 Remington
Defiance Deviant Hunter action
Bartlein barrel, 22", 3B contour, 1:8.2 twist, no brake, 46 rounds at start of test
Manners T1 100% carbon fiber stock
Chambered and bedded by GAP

Conditions:
6200 ft elevation
29.9 Baro pressure
62 F avg temperature
19.5% humidity
Sunny, no clouds
Started at about 9:30 am... Ended around 11:15 am
Wind less than 5mph until last two groups, where it went up to about 10-12 mph

Loads:
H4350 powder
140 gr Berger Hybrids
Lapua Brass
Federal 210M primers
39.0 - 42.2 gr in 0.4 gr increments (1%)
2.880" COAL = 0.020" jump to lands
- Virgin brass, sorted and prepped, expanded in mandrel, then FL sized for uniform neck tension equivalent to final loads

Notes:
- Each shot was chronographed with a CED Millennium II... Not sure if I'm trusting the ES that I was seeing for this.... Bad, bad, bad


Here's a pic of the raw target:

And here it is after being analyzed with the OnTarget Software - vertical distance from POA and chronograph data added:

Groups 7 & 8 look good but I will have to ignore ES at this point. You need to do the test again with fireformed brass to see if ES improves.

 

[Erik Cortina]

Wow, I just realized this thread is 100 pages long!!! By the feedback I have received, it looks like this thread has helped many of you obtain accurate loads which was the entire purpose of this thread.

 

[Hollywood]

I keep.getting notification on new posts to see if I can choose the correct node. I don't have a good track record yet but I'm sure after a little more practice I'll get it figured out.

 

[Erik Cortina]

I keep.getting notification on new posts to see if I can choose the correct node. I don't have a good track record yet but I'm sure after a little more practice I'll get it figured out.

You'll get it figured out, just keep at it.

 

[Hollywood]

I keep.getting notification on new posts to see if I can choose the correct node. I don't have a good track record yet but I'm sure after a little more practice I'll get it figured out.

You'll get it figured out, just keep at it.

I've read all the info it just hasent fully clicked. I'd like to have a pretty good track record at the time I try to tune my rifle. Home range is still frozen with 6-8 inches of snow and I need to square the target board. Winter is never going to end for us.