Vertcal stringing

[Laelkhunter]

I was at the range tinkering with a few different loads for my .340 Weatherby. I was shooting 225 Swift A-Frames, with 3 different powders, RL19, RL22, and IMR 4350.
The best accuracy was with the RL19. I shot the IMR 4350 first allowing about 3 minutes between shots, then let barrel cool for 10 minutes while I went to change targets. When I shot the RL22, I got vertical stringing with a 3 inch group.
I let the barrel cool for another 10 minutes, then shot the RL19, and without anything else being different got a decent .75 group, no vertical stringing.
Is it possible the rifle didn't care for the RL22 to the point that I got a 3 inch vertical group? It shot the 4350 and the RL19 without the vertical stringing of the group. Shooting was at 100 yards, temp was 55 to 60 degrees.

 

[MagnumManiac]

I was at the range tinkering with a few different loads for my .340 Weatherby. I was shooting 225 Swift A-Frames, with 3 different powders, RL19, RL22, and IMR 4350.
The best accuracy was with the RL19. I shot the IMR 4350 first allowing about 3 minutes between shots, then let barrel cool for 10 minutes while I went to change targets. When I shot the RL22, I got vertical stringing with a 3 inch group.
I let the barrel cool for another 10 minutes, then shot the RL19, and without anything else being different got a decent .75 group, no vertical stringing.
Is it possible the rifle didn't care for the RL22 to the point that I got a 3 inch vertical group? It shot the 4350 and the RL19 without the vertical stringing of the group. Shooting was at 100 yards, temp was 55 to 60 degrees.

I'm not exactly sure what your question is, but, the stringing can be caused by an untuned load, just as easily as a velocity swing. You don't mention the range at which you were shooting. If it was short range, then it's probably just barrel oscillation causing the different POI, if it's long range, 500+yrds, then it is probably velocity swings.
Have these loads been tuned at all? I find seating depth just as important as powder charge, BUT, I ALWAYS look for a WIDE NODE, if it is finnicky about .3gr +/- I don't use it, a 1 gr variance is what I look for.

Cheers.
gun)

 

[bob4]

BUT, I ALWAYS look for a WIDE NODE,[\QUOTE}

Cheers.
gun)

would you define Wide Node For a newb like me?

 

[Laelkhunter]

I'm not exactly sure what your question is, but, the stringing can be caused by an untuned load, just as easily as a velocity swing. You don't mention the range at which you were shooting. If it was short range, then it's probably just barrel oscillation causing the different POI, if it's long range, 500+yrds, then it is probably velocity swings.
Have these loads been tuned at all? I find seating depth just as important as powder charge, BUT, I ALWAYS look for a WIDE NODE, if it is finnicky about .3gr +/- I don't use it, a 1 gr variance is what I look for.

Cheers.
gun)

Range was 100 yards, and seating was to the cannelure of the bullet. My question is "why did I get vertical stringing of three inches at 100 yards when the other loads result in a cluster of shots around an inch or less" ?

 

[just country]

morning, I shoot a 340W. I use the TTSX 210gr. barnes. 4831SC 215 primer WB cases.

extremely accurate. just a suggestion. check the burn rate of the powders. Heavy

bullets like slow burning powders.lightbulbgun)

 

[rcoody]

would you define Wide Node For a newb like me?

YOur need to work up loads in 0.30 to 0.50 grain increments. You are looking.for the.accuracy node where barrel harmonics are consistent. Many ways to do this. One of the most popular is the ladder test.
Long-Range Load Development

When you have several load increments that shoot to the same poi you have found a wide node. Pick a charge in the middle and load accuracy is not as critical.

 

[MagnumManiac]

YOur need to work up loads in 0.30 to 0.50 grain increments. You are looking.for the.accuracy node where barrel harmonics are consistent. Many ways to do this. One of the most popular is the ladder test.
Long-Range Load Development

When you have several load increments that shoot to the same poi you have found a wide node. Pick a charge in the middle and load accuracy is not as critical.

This is exactly how I would have explained it.

Range was 100 yards, and seating was to the cannelure of the bullet. My question is "why did I get vertical stringing of three inches at 100 yards when the other loads result in a cluster of shots around an inch or less" ?

The answer was given, barrel oscillation would be the most likely cause, the load isn't within a node, it is varying in barrel time changing the exit point in the barrels position.

Cheers.
gun)