Long Distance Load Tuning

[Shootin4fun]

RockZ, thanks for your quick response...Ugh! Another thing to keep track of when sighting in and changing distances.

I have no way of setting paralax except by setting focus. I will research here and elsewhere...then run some test of my own!

maybe I'll be making my own custom hash marks on the side focus dial of my Monarch, because their yardage markings are way off from the actual target distances. A 100 yard target comes into focus at about 60 - 90 yards on the dial. A 200 yard target comes into focus at about where a 120 yard mark on the dial would be, and so on.

Maybe this is why my POI at 200 is not what I expect sometimes- I forget to readjust for a change in distance and there is no accuracy between factory markings on the paralax/focus dial and actual distance of objects in focus!

 

[loaders_loft]

hash marks are pretty inconsequential. Just look through the scope while turning the side focus or the AO on the front bell until its as clear and sharp as possible. It can help to focus all the way out to infinity first, then work back until its clear. If there is no clear adjustment, its probably mirage, so you can go down in magnification to minimize the mirage effect...

L_L

 

[Wlhofer]

Not sure if this will help you but found this on Berger bullets
Loading Berger VLD Bullets - Shooters Forum

 

[Shootin4fun]

hash marks are pretty inconsequential. Just look through the scope while turning the side focus or the AO on the front bell until its as clear and sharp as possible. It can help to focus all the way out to infinity first, then work back until its clear. If there is no clear adjustment, its probably mirage, so you can go down in magnification to minimize the mirage effect...

L_L

Yes, that is how I do it, but there is a wide range on the dial wherein the target is in focus, and if the setting actually affects POI, then it must be the same setting when I return to that distance. So focus alone may not be precise enough. I typically focus near to far and stick with the "nearest" setting for a given distance but not always. Now that's something I'll have to keep track of.

I'm gonna run some tests this week on a a200 yard target, setting the paralax/focus from nearest point on the dial where the image is sharp and shooting a few, then changing to the farthest point where its in focus and shooting a few.

This may explain why I have experienced some "displaced" but reasonably tight groups. (Where a < 1" 5 shot group @ 200 was 2" higher than it should have been. I've been thinking its the tailwind currents at the range, riding up over the 100 yard berm and actually lifting the bullets. I've been calling them "magic bullets" - ones that show no drop between 100 and 200 yards.)

 

[RockZ]

Check this out
http://www.longrangehunting.com/forums/f18/parallax-vs-focus-1988/

 

[Shootin4fun]

Thanks for the link RockZ! Now we know better how scopes actually work.

 

[jasent]

This is how I fine tune my loads at distance.
http://www.longrangehunting.com/forums/f28/ladder-testing-1k-detailed-article-video-42881/

It is very simple and effective.
It makes finding a good load very easy and cuts down on the amount of rounds needed to find a good load.

+1. I do all my load testing at 300 yards then when I'm happy I test at greater and shorter ranges to double check

 

[Shootin4fun]

This is how I fine tune my loads at distance.
http://www.longrangehunting.com/forums/f28/ladder-testing-1k-detailed-article-video-42881/

It is very simple and effective.
It makes finding a good load very easy and cuts down on the amount of rounds needed to find a good load.

Yes, a very informative article on ladder testing, thanks! In fact I never knew "ladder" was because 1 target is used and "ladder" is a reference to climbing impact points. I always thought the word "ladder" just referred to incremental increases in powder charges.


Many of us are using methods very close to this but with several targtets vs. 1 target. The big thing that the ladder test and the OCW test methodology point out is not to look only for the tightest group, but for a range of "adjacent" loads that share the same impact points. Horizontal grouping seems to be the other main thing they say to look for, saying that vertical dispersion is a negative and horizontal dispersion is usually due to wind. I'm not sure I agree with a statement that says horizontal dispersion is generally due to wind, but I get that vertical can be due to charge/case/primer variances as well as barrel harmonics. Lastly, testing at intended ranges is great if you have the range availability and ambient conditions cooperate, but depending on where you shoot, either of those may not be readily available (long range paper targets & lack of wind).


I HAVE noticed that when I find an accurate load, I can usually vary the charge a +/- .3gr with little change in accuracy and POI as they describe is the intended the result of their methodology. So I guess that means I've been finding the right nodes despite not following the proceedures described in the ladder article.


I In any case, the proof is in the pudding.