600 yard ladder or 100 yard groups?

[odoylerules]

300 win mag, 27" barrel. Nosler brass, H-1000 powder, Berger 215's.
Here's where I am in my load development. I found a great accuracy node between 76.2 gr and 76.8 gr, .020 off the lands.
76.2 avg velocity 2930fps, SD-5.4 ES-10
76.5 avg velocity 2943, SD-3.1 ES-6
76.8 avg velocity 2944 SD-5.5 ES-11
So I was planning on loading up right in the middle at 76.5 grains. My question is the next step. I'm going to play with seating depth. 0.010-0.040 in 0.005 increments. Do I shoot a long distance ladder test to look for vertical dispersion, or shoot 100 yard groups?

 

[Rhovee]

If your already seeing great accuracy with .020 off then I would test +\- .005 from that. Even then I would shoot a ladder at 600 with 76.2 and working up past 76.8. You should be able to see where she levels off at. To me shooting at distance will always show you more of what's going on then short range group. That's if the weather is good.

 

[Joefrazell]

Personally I'd shoot 100 yards if doing seating depth development. How are the groups at .020? Don't over think it too much. As long as your getting the accuracy and sd's your looking for I'd try to stretch the load you have out to 600 and see how she holds up. From all my experience, once I have a load that accurate at 100 with good sd numbers it will shoot well at distance. For me 100 is just much easier to deal with during development and tells me what I need to know. I know lots of people that shoot longer range during LD and it works great for them and that's great, i use to as well but have went to 100 yards exclusively. Not saying my way is better but it is better for me. More then one way to skin a bear, I say bear because I've never skinned a cat.

 

[odoylerules]

I haven't shot groups yet. I didn't have a scope to put on it, I do now. I just shot 3 shots at each charge with the magnetospeed looking for the nodes. I hit pressure signs at 77.7 grains.

 

[odoylerules]

Maybe I should split the difference? shoot 2-300 yard groups

 

[NEMTHunter]

Not trying to be rude. But you wasted shots. I always do load work up buy speeds es and sd and the same time see how it does down range kill most birds with one stone.

I take the load that is the best. Then move out from there.

 

[NEMTHunter]

Your 76.5 load looks good! I would think that one should shoot great. Try it and see how it does.

 

[odoylerules]

Not trying to be rude. But you wasted shots. I always do load work up buy speeds es and sd and the same time see how it does down range kill most birds with one stone.

I take the load that is the best. Then move out from there.

I agree I did shoot 30 rounds and definitely could have been a lot more efficient about it. I was waiting for my scope to arrive and was really bored to be honest so I just wanted to do something to get the load development started.

 

[NEMTHunter]

LOL I understand that perfectly. Its hard to keep the hands off a new gun!

 

[C.O. Shooter]

See what your gun does at 100. If you have two groups that are close, shoot those both at 600 and 1000 yards and see how they perform. Adjust accordingly. You'll be better to see any vertical or horizontal stringing at those distance.

 

[Canhunter35]

After reading your other posts, I would shoot at a hundred at ur 76.6 gr, middle of your node. Test at .02" and .05" and .08" from the lands then if one groups better you can work .005" around it, pinpointing the right depth

 

[Trm82]

I always do load development at 200 yards , it tells you a lot more than 100 yards groups.

 

[Rich Coyle]

I always do load development at 200 yards , it tells you a lot more than 100 yards groups.

How?

 

[FNA3G]

100 yds is plenty far to perform testing. Im not a fan of long range ladder tests due to statistical anomalies from the accuracy of the rifle and shooter plus weather conditions. Too many variables for any meaningful data analysis without shooting multiple examples of the same settings with a control group to act as the constant. A good chronograph to provide accurate SD and ES plus a good charge weight workup at 100yds will provide much better data than single rounds of charge weights at distance. However I am all for confirmation testing at distance with the load you expect to shoot but not developing a load at distance.

I am an engineer by trade and I originally did the ladder test and so on but after working on rifles for 15 years now and tracking all my data through countless load workups for customers every way under the sun I have formed my own opinions on what has any real impacts on the outcome. There are many ways to skin the cat but I believe the following to be true:
1.) 100yds is close enough to minimize weather and shooter error while being far enough to begin to show undesirable variances
2.) Low SD and ES in succession (flat spots) with different charge weights very often indicates optimal charge weights. Theres always outliers but thats why more rounds at 100yds is better than few at 600 for data comparison.
3.) A good load at 100 is a good load at 600 and a bad load at 100 is bad at 600. Its impossible for bullets to scatter at 200 yds just to come back together at 800 without outside influences.
4.)Charge weight first, seating depth second only if necessary. No reason to adjust depth in increments less than .005 because our calipers are accurate to +/-.001 and without constrained, repeatable measuring practice such as a friction thimble you can figure that adds +/-.002. ( numbers come from my records on operators measuring bearing raceways at my day job). Also the throat on hot calibers can erode at first by more than .001 within 100 rds, so if you believe you find the sweet spot by dropping .001" at a time then dont load more than 50 rounds in a sitting at that depth or you will fall out of your magical bubble at round 51.
5. Just because you shot 1 3 round group of .300" does not mean your rifle is a 1/2moa rifle nor does it mean you have an issue if tomorrow it shoots .600".