tune at 100 fell off at 200

[Link]

Some guys can tune for 600 or 1000 at 100 but what happens when -
We had a great tune for the 6BR at 100 but fell apart at 200 . 1-8t 108s. Varget , 450s
We have gone from 29.5 at 100 to 30.2 at 200 - 400 with better results.
[30.3 started cratering primers] and still not done with seating tests
# What happened?

thanks Don.

 

[JEFFPPC]

I have found personally over the years if I have a really good set up at 100 and I drop off from there to 500 it is my wind/flag reading skills that need the work. I am much more concerned with conditions than the gun these days. Might just be me though.

 

[Liven The Dream]

I will see this jumped on 100 No ?
I tune at 200 for Target and Hunting Rifle. Then 300 for Target Rifles I shoot at 600 and 1000.
I assume 108's are Berger ?? I shoot 105 Berger HB in a Dasher . I found seating to be the Key.
My Dasher shots Bug Holes with Varget CCI 450's those 105's right on to .010 off the lands.

best of luck

 

[Dusty Stevens]

Usually thats a sign of a light load that gets pushed around in 100 more yards of conditions you didnt see

 

[Big Mc]

Some guys can tune for 600 or 1000 at 100 but what happens when -
We had a great tune for the 6BR at 100 but fell apart at 200 . 1-8t 108s. Varget , 450s
We have gone from 29.5 at 100 to 30.2 at 200 - 400 with better results.
[30.3 started cratering primers] and still not done with seating tests
# What happened?

thanks Don.

Dusty got it right. Tommy Mc

 

[dttheliman]

Usually thats a sign of a light load that gets pushed around in 100 more yards of conditions you didnt see

Dusty is invariably correct , did you run them over a chrono?

 

[dgeesaman]

Is it a 200 range where you’ve shot consistently good groups before? My home range shoots predictably to 100y but the 200y for some reason gives everyone fits. The benchrest competitors who practice there rarely use their ammo on it. The other ranges I visit aren’t as tricky to shoot 200y.

 

[RGRobinett]

Usually that's a sign of a light load that gets pushed around in 100 more yards of conditions you didn't see

!! And, there, you have it! Relative to 100 Yd., 200 Yd., requires >four times+ better wind "doping"! By one exterior ballistics calculator, STD conditions, constant perpendicular vector and velocity from muzzle to target (when have you ever seen THAT??), via 68 Gr. 6mm bullet at a full-blown 3400FPS:
1)100 Yd., 1MPH change = 0.090" wind-drift;
2) 200Yd., 1MPH change = 0.390" wind-drift.
A factor of 4.333 . . . "nobody said it was going to be easy" . . . redundantly, and at risk of offending, this is
PER mile-per-hour of variation . . . it's linear & "subject to change without notice". Keep 'em ON the X! RG

 

[Bronsin]

I had the same thing happen with 28,2grs of N133 in 6PPC. Shot great at 100yds, anywhere from 90 to 76 degrees. Looked like a shotgun at 200. I'm going to test it this weekend, but I don't anticipate the same results with 29.3grs of LT-32.

 

[JEFFPPC]

Usually thats a sign of a light load that gets pushed around in 100 more yards of conditions you didnt see

I seldom disagree with Dusty but on this one I will.,The light load one might shoot in a Dasher, BRX, BRA, whatever, is a hot or maybe too hot load in a BR. Too much emphasis on gun, not enough on bench manners , flags/ conditions. Randys point as given is excellent.

 

[Falfan2017]

I’ve found 200 yards to be a weird yardage. I can get something going at 100 and it shoots pretty well at 600 or 1000 but to get something to really shoot well at 200 I have to tune at 200. Then that 200 hard tune doesn’t seem to work at other distances

 

[Link]

Dusty is invariably correct , did you run them over a chrono?

No not yet.

 

[RegionRat]

A description or photos of the groups as well as a description of the rig is helpful.

The wisdom above on the windreading differences between 100 and 200 are very important.
There is also some benefit to chrono numbers if you had them just to make sure your tune was really locked in on both occasions.
This would just help give a better view of the relative tune of the “good 100” load versus the “not so much 200” load. This isn’t meant to be misconstrued as advice to chase chrono numbers, but to be used as another verification or lock on what you liked that day.
There are times when powder volume clicks are unreliable on days when humidity and temps swing, or days when those issues change the cleaning regime.
Sometimes it is the driver and their bench manners and ability to read wind, sometimes it is the state of the barrel/equipment or the load.
We all go through this at some point, and it takes work to solve the question of arrow or Indian. Even then, after we have verified the issue to the arrow or the Indian, the work has just begun.
ETA: on days when things go bad at distance ”B”, if at all possible it is good to get a test of distance “A” in the same conditions. It helps tell us if it is really the case that the tune was good at A that day.

 

[Link]

Sorry I didn't post the target. I didn't think I could get much from it. This is all 200 yd. with flags. I'm still working on it. thanks Don.

 

[Ccrider]

Looks like a weather report on an out of tune rifle.

 

[CNC-Dude]

Erik Cortina mentions in one of his videos about seating depth, that having a good group at 100 yds. but it opening up at farther distances can be evidence of selecting the wrong node. Did you do any ladder tests or other form for load development...?

 

[jackieschmidt]

I have shot a LOT of 100/200 yard Benchrest, and feel that what shoots good at 100 shoots good at 200.

But, as many said, the condition reading requirements are substantially more at 200.

That is why Grand Aggregates are invariably won at 200.

 

[JEFFPPC]

I have shot a LOT of 100/200 yard Benchrest, and feel that what shoots good at 100 shoots good at 200.

But, as many said, the condition reading requirements are substantially more at 200.

That is why Grand Aggregates are invariably won at 200.

I think this holds pretty true for any multiple distance match. If you are at or near the top at the longest distance you are in good shape when rewards are announced.

 

[Rset]

Sorry I didn't post the target. I didn't think I could get much from it. This is all 200 yd. with flags. I'm still working on it. thanks Don.

View attachment 1358036

I have never seen 200 yard targets that bad with a good 100 yard tune. I would go back to 100 and verify your information.

 

[RegionRat]

Is this a case of a rig that ran well at 200 before, or only at 100?

Good idea to run tests again at 100 to see if you can run well at 100 and then 200 on the same day.