Load Development at LR

Downeast

Downeast

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I've been reading some lately and even have seen a few videos on working up and testing a load at 300 or 600 yards. Generally one works up a load at 100 and then dials up to see if the group will hold together at LR. Would it be valid to load a series of differing powder loads and shoot for groups at 600 to see if there was a difference? Giving that you started with your best load at 100, then move .3 grains up or down to see if that is the best load at distance?
 
I don’t know what valid means in this context, but it seem inefficient to develop an initial load at 600, lots more walking, lots of shots not on paper, and lots more noise in the results from environmental factors (wind). What would the upside be? Maybe find something good at 600 that was not a contender at 100 or 200?
 
@Downeast

Developing a load at 100 is the same effect at 600, but at 600, you can see the dispersion of shots better. IE at 100yds you might measure a group as .7 MOA and at 600yds you might find more of a .6 MOA reality.

For me, the key is to shoot fast and hold tight. I only measure the vertical dispersion past 500 yards. The left/right could be a bad wind call. But normally the vertical will hold the MOA I need.

Now, if you do the OCW load development technique at 100, find the OCW and then dial the, bullet Jump, and charge with a .2grn at 600, I think you will have a better result.
 
@GymB
That's why I ask. From what I've seen online it seems like some sight in at 100, then check the load at LR. If if it doesn't meet their expectations they check seating depth or tweak loads to verify that it is the best the rifle will do, all things being equal.
 
The rabbit hole on this subject goes VERY deep, and there are multiple routes to take. One common route is when developing loads at 100yds is utilizing a chronograph to record your velocity to generate the standard deviation(SD) and extreme spread(ES) of a string of test rounds (5-10). Knowing these values you can begin to generate a ballistic curve/solution for the round and evaluate the SD & ES, which you want to be minimal. SD's under 10 and ES's under 30 are preferred as minimal velocity variance results in minimal vertical dispersion at range. This is not only an exercise in load development but an evaluation of your reloading process, technique and capabilities. In my experience the two main contributing factors to minimizing SD & ES are: 1. consistent case neck tension through annealing cases and sizing with a proper bushing & mandrel. 2. delivering consistent powder charges accurate to 0.02gr.

If you have not found the site yet Snipers Hide is a wealth of information:

www.snipershide.com

Reloading Depot

Open discussion on reloading, *always exercise caution* when reloading
www.snipershide.com www.snipershide.com
 
Snipershide as mentioned has a wealth of information on the subject
Reloading for long range thread, from case prep on out.
Very knowledgeable bunch

Also Bryan Litz has some great information. Applied Balistics ..

Edit: Using the 338LM here a chrono is important but.
Development of a load at 100yd then shoot at 500, see what happens, do some fine tuning, then 1,000. Powders here are IMR-7828, H1000, Berger bullets, Lapua Cases..
Yeah. Yeah its overkill at a 100yd
Just making it short with out rambling

-Snoopz
 
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Thanks for the replies. That rabbit is digging deeper holes...;)

I'm going to shoot some more 600 yard groups and see if they are at least consistent. I just need a break in this weather. When I try to shoot at dawn the fog is thick and hot. Talk about miserable.
 
JBoyette said:
I only measure the vertical dispersion past 500 yards. The left/right could be a bad wind call.
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Great point. Better to keep the same POA during load development and ignore the horizontal spread. Hadn’t thought of that.
 
Now.......I'd rather test at 100, then based on the results, try it out at a longer distance. Keep up with what groups good and your ES and SD. Even if it groups great and the ES is terrible, try it at longer ranges so you know, and the opposite. Bad groups with great ES, try them out too. This is just my opinion...... if the load is consistently bad a shorter distances, it will not get any better at longer distances.

The issue with testing at longer distances is the wind. If the load has horizontal spread at 100 and and 600, it's the load. If the horizontal spread is good at 100 but not 600.... is it the wind? It's very common for the wind to pick up and die down a bit........ this can confuse you with bad horizontal spread. Sometimes you get lucky and there's next to no wind, but that doesn't seem to happen very often for me! If you're fortunate enough to have a longer range close by, then you can probably find days when the wind if favorable to try it out.

I'm going to do some testing one of these days, but I have some old load data when I used my Competition Electronics Chronograph that had GREAT SD and ES. I've been using the LabRadar for a couple of years now, and I just can't seem to get the same great SD and ES as I did with the Competition Electronics Chronograph. Sometimes I will get a ES of 60 fps or so, but the load usually still groups very good. If your ES is bad and your vertical spread is bad at longer ranges, your chronograph isn't lying to you.
 
Without going back to my notes my SD usually runs around 10 or less. I have a magnetospeed and have started using it on every string. I figure the more data the better. This is my last 600 yard target with 10 shots. Almost like two groups and doesn't make a lot of sense to me.

But nine out of the ten shots were in the 10 ring. I figure that I'll shoot a few more groups and see if there is any consistency or was this just a random event?


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Been following Erik for sometime. Some very good interviews with a lot of excellent rifle shooters. Some good info if you have the time to listen.
 
What is your front rest/rear set up like? Oh, and that's not bad tat all!!!
 
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Downeast said:
Without going back to my notes my SD usually runs around 10 or less. I have a magnetospeed and have started using it on every string. I figure the more data the better. This is my last 600 yard target with 10 shots. Almost like two groups and doesn't make a lot of sense to me.

But nine out of the ten shots were in the 10 ring. I figure that I'll shoot a few more groups and see if there is any consistency or was this just a random event?


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That spread to two groups looks to me to be a parallax/diopter adjustment setting on the optic. ITs looks like two different point of aim holds
 
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