600 Yard Ladder Results

[dcali]

That’s a pretty clean ladder, with some obvious potential around 5-6. That said, sometimes they don’t repeat.

As for tuning up close or at distance, a lot of folks make assumptions on the setup. If you’ve got a proper br rig that you can shoot quickly, and can shoot on a calm day, then by all means, stretch it out.

If you’re going to be shooting more slowly or in less than ideal conditions, do it up close (at 100) and then verify later at distance. 100 yard tune is going to be very close to what you want at distance.

The trouble with tuning at long range in the wind is that a horizontally out of tune load and minor wind variation look the same. Some guys are content with a wide, flat group at long range because they assume it’s all wind. But sometimes, it’s not. It’s just a horizontally strung group, and it causes all kinds of problems in f class especially, since it makes it seem like there is invisible wind when it’s just a lousy load.

You can save yourself some headaches by tuning up close before fine tuning at distance.

 

[MattPeetz]

That’s a pretty clean ladder, with some obvious potential around 5-6. That said, sometimes they don’t repeat.

As for tuning up close or at distance, a lot of folks make assumptions on the setup. If you’ve got a proper br rig that you can shoot quickly, and can shoot on a calm day, then by all means, stretch it out.

If you’re going to be shooting more slowly or in less than ideal conditions, do it up close (at 100) and then verify later at distance. 100 yard tune is going to be very close to what you want at distance.

The trouble with tuning at long range in the wind is that a horizontally out of tune load and minor wind variation look the same. Some guys are content with a wide, flat group at long range because they assume it’s all wind. But sometimes, it’s not. It’s just a horizontally strung group, and it causes all kinds of problems in f class especially, since it makes it seem like there is invisible wind when it’s just a lousy load.

You can save yourself some headaches by tuning up close before fine tuning at distance.

Thats because people interpret the ladder incorrectly.
Sure, ideal conditions are ideal but rarely ever there.
People interpret close range tests wrong too.
Interpreting is the whole key

 

[seymour fish]

Mr Fish,
Check out Varmint Al's web site as well as a book
by Graham Mincham called Optimum Barrel Length. You may not want to do what Mr. Mincham prescribes as it entails shortening the barrel a bit. I and my Australian friend do the longitudinal tune then tune our tuners. This book is sold by South Australian Rifle Association
phone # 0882445533.
Varmint Al has some great articles using Finite Element Analysis about rifle resonances. He also connects it to the OBT theory.

Norm, longtime fan of Varmint Al’s. Have spoken with Chris Long. Played with rimfire tuners since ‘04. Have reverse-engineered my best loads for mid and long range and generally find bbl times 1% longer than Chris’predictions. Do you look for this correlation, or simply do a pragmatic scan for widest node of lowest ES ? The “why” is of much interest, and will have some fun with this. Have noticed some innovative thoughts on Ozfclass. Will obtain the book. Many thanks , Seymour

 

[normmatzen]

Seymore,

I, too, spend a lot of time on OZFClass. A lot of good info on tuners.
I use Quickload to do load comparisons as well as finding most efficient powder for a given cartridge. It is a good back up for tested data. The longitudinal resonance creates a "moving donut" and when the barrel time matches just off that speed, the Mv can be modulated a bit by the barrel tightness enough to improve the Mv ES. Of course as has been stated on this forum before, this isn't a metric for accuracy. So, I depend on the longitudinal resonance to keep the Mv as close to constant that I can and depend on the tuner and cantilever resonance to sometimes yield positive compensation at longer distances. This combination has worked well for me. Now, if only I could improve my shooting skills!!??

The popular ladder test is a way to combine both these resonances in one test, but I don't trust 1-3 shot per powder load to be statistically viable. I would trust 5 shot round robin ladder test way more if I wasn't using a tuner.

 

[seymour fish]

Norm, Keeping the dilatory donut off the crown at bullet exit has been a cornerstone of the longitudinal resonance thinking which I am familiar with. Is there a suggestion of some compensatory tightening of the bore after the wave reflects, giving some “choke” ? Just thinking out loud. Have found it easy to develop good long range accuracy with very low ES in a few old Sakos which are hammer forged with some choke, hence the question. Seymour