Load development- where to go from here?

coyoteking

coyoteking

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I shot this today at 100 yards from a RPR in 6.5 cm.

42.9 grains is the listed max load, I’m wondering, based on the extreme spread, if maybe I’m just at the start of an accuracy node at that charge weight? Should I try 43.1 or is that 42 gr load what I should be going for?

There were no pressure signs at 42.9 gr.

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I would try 10 shots of 42.0, 43.0 and 43.3

5 shot groups are not as meaningful as a 10 shot group.

And I would shoot at 300, not 100, so the barrel harmonics can show up. Your .218" group might be terrible at longer range. (Unless you have no intention on shooting 300 to 600 yards)
 
Well I don't have anything really to add as I am very new to this same journey.


But, besides ES (extreme spread), you could also throw in another calculation of "standard deviation".
Enter your speeds
https://www.calculator.net/standard-deviation-calculator.html

I have been reading that having consistent speed of your reloads is a better indicator of accuracy the further downrange you get, than having tight groups at 100 yards. Of course, shooting at longer ranges will be the best test but many of us don't have access to shooting ranges beyond 100, 200 or 300m
http://precisionrifleblog.com/2015/04/18/how-much-does-sd-matter/

6.5 Guys have some good videos...
 
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Where to go from here?

Shoot farther away. Plenty of small groups at 100 yards open right up as range increases. Find something with a low sd and work on seating depth. I like testing at 300
 
Ganderite said:
I would try 10 shots of 42.0, 43.0 and 43.3

5 shot groups are not as meaningful as a 10 shot group.

And I would shoot at 300, not 100, so the barrel harmonics can show up. Your .218" group might be terrible at longer range. (Unless you have no intention on shooting 300 to 600 yards)
Click to expand...

Thanks Ganderite. This sounds like a plan.

Once I get a load developed I’m planning on doing most of my shooting beyond 300.
 
I'd be chasing the ES. A higher es won't kill you at a 100 yards, but as you go further and further it'll hurt you more and more.
 
coyoteking said:
Thanks Ganderite. This sounds like a plan.

Once I get a load developed I’m planning on doing most of my shooting beyond 300.
Click to expand...

You can't develop a load for "most of my shooting beyond 300" at 100 yards. You are wasting time, powder and bullets (and barrel life).

100 yard groups are good for 100 bench rest competition.

Barrel harmonics trump ES and SD and determine accuracy. You can't see their effect until you shoot at 300 or more. My preference is 500 on a calm day.

I don't test any match ammo at 100, nor do I bother with ES and SD. I just test velocity as a preliminary step to get me into the velocity range I need.

The other posters who suggested testing at a longer range have also learned this lesson. (Probably from their own experience.)

This is a 525 yard test of a 308 shooting 155gr Sierras from a 28" Krieger in a single shot Musgrave action. The group measures about 1 3/4" high. This tells me the harmonics are about perfect. The powder used was a non-canister Bofors product - RP28. New Winchester brass with Federal 210M (Match) primers.

I shoot 20 shot groups, so that the one group probably means something. The "rifle" used was a rail gun. Although there was some wind during the test, all 20 shots were fired in less than a minute, so wind changes were minimal.

vM2tcbE.jpg
 
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Ganderite said:
You can't develop a load for "most of my shooting beyond 300" at 100 yards. You are wasting time, powder and bullets (and barrel life).

100 yard groups are good for 100 bench rest competition.

Barrel harmonics trump ES and SD and determine accuracy. You can't see their effect until you shoot at 300 or more. My preference is 500 on a calm day.

I don't test any match ammo at 100, nor do I bother with ES and SD. I just test velocity as a preliminary step to get me into the velocity range I need.

The other posters who suggested testing at a longer range have also learned this lesson. (Probably from their own experience.)

This is a 525 yard test of a 308 shooting 155gr Sierras from a 28" Krieger in a single shot Musgrave action. The group measures about 1 3/4" high. This tells me the harmonics are about perfect. The powder used was a non-canister Bofors product - RP28. New Winchester brass with Federal 210M (Match) primers.

I shoot 20 shot groups, so that the one group probably means something. The "rifle" used was a rail gun. Although there was some wind during the test, all 20 shots were fired in less than a minute, so wind changes were minimal.

vM2tcbE.jpg
Click to expand...


Thumbs up, i enjoyed this post!
 
350 Mag said:
What kind of Chrono you using....

Lately I have come to conclusion that optical style chronographs probably have more value as a paper weight .
Click to expand...

I will agree there. I had a shooting chrony that would read the same load sometimes 3000fps difference. Hell I think I was shooting 180gr in 30-06 once that were going 3200 or so fps one shot and the next 1200 fps.
 
Ganderite said:
You can't develop a load for "most of my shooting beyond 300" at 100 yards. You are wasting time, powder and bullets (and barrel life).

100 yard groups are good for 100 bench rest competition.

Barrel harmonics trump ES and SD and determine accuracy. You can't see their effect until you shoot at 300 or more. My preference is 500 on a calm day.

I don't test any match ammo at 100, nor do I bother with ES and SD. I just test velocity as a preliminary step to get me into the velocity range I need.

The other posters who suggested testing at a longer range have also learned this lesson. (Probably from their own experience.)

This is a 525 yard test of a 308 shooting 155gr Sierras from a 28" Krieger in a single shot Musgrave action. The group measures about 1 3/4" high. This tells me the harmonics are about perfect. The powder used was a non-canister Bofors product - RP28. New Winchester brass with Federal 210M (Match) primers.

I shoot 20 shot groups, so that the one group probably means something. The "rifle" used was a rail gun. Although there was some wind during the test, all 20 shots were fired in less than a minute, so wind changes were minimal.

vM2tcbE.jpg
Click to expand...

Good info.

I’ve been reloading for hunting rifles for a few years, this is my first attempt at reloading precision ammo for long range.

For other rifles I’ve loaded in the past I’d usually start with a ladder test at 400 yards, then use that data to narrow the selection down to a couple of charges based on accuracy nodes, then shoot for groups at 100 yards.

ES and SD are new concepts to me, but I understand how they affect shot to shot consistency out past 600 yards.

I guess what I was attempting here was to find a low ES while doing an OCW test. Maybe not the most efficient way to develop a load. When it comes to long range load development there’s a lot of information to wade through on the internet and with all the YouTube videos I’ve been watching on the subject I think I’ve reached information overload.

I really appreciate the help ganderite, I’m going to continue with this load development using your method and see what I come up with.
 
Ganderite said:
Barrel harmonics trump ES and SD and determine accuracy. You can't see their effect until you shoot at 300 or more. My preference is 500 on a calm day.

I don't test any match ammo at 100, nor do I bother with ES and SD. I just test velocity as a preliminary step to get me into the velocity range I need.


This is a 525 yard test of a 308 shooting 155gr Sierras from a 28" Krieger in a single shot Musgrave action. The group measures about 1 3/4" high. This tells me the harmonics are about perfect.
Click to expand...

Ganderite...is there a relationship between barrel harmonics and velocity for a given rifle and bullet weight? In other words if I am noticing repeated accuracy nodes at a window of velocity range in a rifle with same weight bullets, that looking for that velocity window (with same weight bullets ) in the same rifle is probable or predictable for accuracy? EDIT, or is this thinking false and I am fluking it off or the rifle is an anomaly?

Pardon any ignorance of my part, just trying to follow along with the information presented.

Noted on your comments regarding ES and SD. As well, to note: I load for hunting and to produce the most accurate ammunition I can with the tools I have, the locations available, and the knowledge I am gaining. Ranges I am comfortable in the field is up to 300 "ish" depending on circumstance and the rifle I have in my hands at the time. Side project is to see how well I can apply what I am retaining for plus 300 accuracy. Don't have the location to test at longer distances...yet.

Regards all,

Ronr

EDIT. I need to acknowledge the photo posted. I tip my hat to that.
 
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hometownhero said:
I will agree there. I had a shooting chrony that would read the same load sometimes 3000fps difference. Hell I think I was shooting 180gr in 30-06 once that were going 3200 or so fps one shot and the next 1200 fps.
Click to expand...

Mine would change...

sunny day 100-150 fps faster.
Cloudy ...slower.


The biggest thing I found....was I would shoot the exact same load 2 days apart I. Same conditions.

The ES and SD would go from 10&5 to 50&25???

So I am starting to learn that you have to watch what your groups are telling you, watch Chrono....then shoot at 500 yards(+).....that's where your going to see IF you got an accurate load.
 
350 Mag said:
Mine would change...

sunny day 100-150 fps faster.
Cloudy ...slower.


The biggest thing I found....was I would shoot the exact same load 2 days apart I. Same conditions.

The ES and SD would go from 10&5 to 50&25???

So I am starting to learn that you have to watch what your groups are telling you, watch Chrono....then shoot at 500 yards(+).....that's where your going to see IF you got an accurate load.
Click to expand...

I used to notice the velocity sometimes vary 100fps when the sun went behind a cloud. I bought a Magnetospeed, and no more issues with light conditions.
 
stubblejumper said:
I used to notice the velocity sometimes vary 100fps when the sun went behind a cloud. I bought a Magnetospeed, and no more issues with light conditions.
Click to expand...

I recently bought a v3

350 Mag said:
Does the weight of it on end of barrel change harmonics or P.O.I?

Definitely on my "must" have list.....
Click to expand...

It does for me. On my m70 fwt's the change is about 5" high at 100. Other light barred hunting rifles are similar. My one custom with a number 5 contour changes about 2" higher at 100. Only one that doesn't change is my truck axle barrel it is 26" ling and 1" at the muzzle with a 6mm hole in the middle.
 
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