how to fix vertical dispersion?

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triple tap

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just got back from testing out some hand loads for 223 Remington. at 382 yards I had a gong set out there and my group was about 1.75 inches wide but about 5 inches tall... and most of my misses on the small targets where over or under the target, always good windage... i wanted to try out these new bullets so I made up a batch of 100 to see how they would work but they are getting bad vertical dispersion... what do you guys recommend I try and change first?


load setup:

75GR hornady BTHP loaded 10thou back from the lands
full length sized brass
24GR of varget (no pressure signs at all)
CCI #450 small rifle magnum primers

im thinking ill set them to the lands and then slowly increase the charge weight till I see pressure signs or good groups... am I on the right track or should I try something else first? this is my first time loading past mag length and loading for precision so much of this is new to me...

thanks.
 
Bed the rifle if not already done and load to a 0.02+/- hundredth of a grain and play around with the seating depth. The 223rem cartridge being smaller case capacity is sensitive to powder weight inaccuracy. Shoot over a Chrony to determine your Velocity,ES and SD. This will help determine which load will give you a most consistent performance.
 
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A chronograph is an unnecessary reloading tool.
Vertical groups are rarely caused by the load. Add the W's. .6mmbr.com/verticaltips.html
 
sunray said:
A chronograph is an unnecessary reloading tool.
Vertical groups are rarely caused by the load. Add the W's. .6mmbr.com/verticaltips.html
Click to expand...

Dear sunray

If your going to give out information you should know something about the subject AND AT LEAST READ THE FRIGGING LINK YOU HAND OUT.

CURES for VERTICAL STRINGING
http://www.6mmbr.com/verticaltips.html

LOAD TUNING

• Find the Sweet Spot--A load that is too light or too heavy can cause vertical problems. When you've tuned the load right, you should see a reduction in vertical. Even 0.1 grain may make a difference, as will small changes in seating depth.

• Primers--If you're getting vertical, and everything else looks fine, try another brand of primers. And remove the carbon from the primer pockets so the primers seat uniformly every time.

• Case Prep--When you chamfer the inside of your case necks make sure they are smooth enough that they don't peel jacket material off when you seat the bullet. Bullets with J4 Jackets (like Bergers) and Lapua Scenar bullets seem more prone to jacket scratching or tearing than Sierra bullets.

Below changing the up pressure at the fore end tip on non-floating barrels or varying the receiver screw torque on a free floating barrel will effect the barrels vibration pattern.

MECHANICAL and HARDWARE ISSUES
Stock Flex--Some stocks are very flexible. This can cause vertical. There are ways to stiffen stocks, but sometimes replacement is the best answer.

Example, a loose fore stock on a Enfield rifle will cause vertical stringing and a loose butt stock will cause horizontal stringing.

Bottom line, its all about barrel vibrations and getting the bullet to leave the barrel at the same vibration point or node.

And sunray you don't "node" nothing about the subject.
 
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AND AT LEAST READ THE FRIGGING LINK YOU HAND OUT.
Click to expand...

I rarely, if never stick up for Suntan, but...he was trying to provide a link without hot linking.

"w's" was his way of shortening "www" CGN does not necessarily like hotlinking

Regards
 
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yomomma said:
I rarely, if never stick up for suntan, but...he was trying to provide a link without hot linking.

"w's" was his way of shortening "www"

Regards
Click to expand...

sunray said:
Vertical groups are rarely caused by the load.
Click to expand...

yomomma

The link sunray posted clearly states the load "CAN" cause a vertical, if you had read the link and then looked at the blue portions of my post you would have seen they were copied from this link.

This means sunray didn't understand what he read at the very link he wrote and as usual he posted pure garbage.
 
triple tap said:
just got back from testing out some hand loads for 223 Remington. at 382 yards I had a gong set out there and my group was about 1.75 inches wide but about 5 inches tall... and most of my misses on the small targets where over or under the target, always good windage... i wanted to try out these new bullets so I made up a batch of 100 to see how they would work but they are getting bad vertical dispersion... what do you guys recommend I try and change first?


load setup:

75GR hornady BTHP loaded 10thou back from the lands
full length sized brass
24GR of varget (no pressure signs at all)
CCI #450 small rifle magnum primers

im thinking ill set them to the lands and then slowly increase the charge weight till I see pressure signs or good groups... am I on the right track or should I try something else first? this is my first time loading past mag length and loading for precision so much of this is new to me...

thanks.
Click to expand...

First off, that's great horizontal dispersion. You don't mention what the wind was, if any, but that's some good shooting. So that's the good news. You've got a rifle and load that wants to perform.

First question I'd ask here is do you KNOW the rifle will shoot? Does it shoot factory or other hand loads better? Unless this issue is only occurring with these loads, I'd first look at the rifle; specifically barrel floating, then bedding, then mounts & rings. If you KNOW it's not the rifle, or you, then that takes us to the loads.

24.0 Varget / 450 / Horn 75 BTHP should be pretty much a guaranteed good load - those 75 BTHPs and anywhere between 24 - 25.0 Varget should shoot very well from just about any rifle. Indeed, I shoot the same load when I feel like changing it up from the AMaxes, and even variations with other powders (748, H4895, N140) are near enough in accuracy as makes no difference.

Normally I'd say a chrono is a nice to have, as results on paper matter, not what the chrono spits out. IOW, I'd rather have hard data from actually shooting a given load at given ranges with ZERO velocity data and true the ballistic software to reality than have just velocity data and predict the drops from software. That said, a chrono would be a very good tool here to help diagnose the problem. It would take +/- 125 fps will get you +/- 2.5" at 382 yds according to Strelok. That's not impossible with inconsistent loads, but it strikes me as unlikely if care is taken - an ES of 250 fps is very very very high. How are you measuring powder? You'd need something around +/- 0.5 grain (!) to introduce that velocity spread if the issue is inconsistent powder charges. The primers are another possible culprit for high ES/SD; the 450s are a magnum primer and in the .223 variations in their energy will have a much larger proportional effect than in cases with larger capacities. If the issue is high ES/SD, and you KNOW your charge weights are consistent, I'd try 400s and BR4s or the Wolf SR primers. Again, that said, my own testing with the 75 AMax / 25.0 Varget / Hornady case showed no appreciable difference between the three CCI primers; SDs were within a few FPS of each other, the only diff was the 450s push things 100 fps faster than the same load with 400s and BR4s. That's one load, one gun and one guy though - YMMV!
 
The OPs original post left out a lot of important information.

The ammo is shooting vertical groups. His concerns are related to ammo. This implies (but does not say) that other ammo is not vertical.

First thing to look at is the rifle. is it bedded by someone who knows what he is doing? If not, the rifle is not as good as it could be.

To test your bedding, put one hand lightly around the forend/barrel and slack off the front action screw. Did the barrel rise a bit? If so, the action is being flexed by the action screws. It needs to be bedded.

Is the barrel free floated with lots of clearance. If the barrel touches wood it can cause vertical stringing.

Shooting technique. Shooting from a bench? With a rear bag? Is your cheek touching the stock? if so, you are adding a variable flexing action to the rifle which causes vertical stringing. When I shoot off a bench, I don't shave. I let my whisker stubble touch the stock. I can reproduce that for each shot.

"Cheek weld" is a factor only when shooting unsupported, as in off hand or prone, off your elbows. It is a disaster off the bench if the rifle is bagged front and rear. Resting your head on the rifle, between the two bags, is adding a major flexing variable.

Ammo. Shoot over a Chrony and see what your ES and SD is. 385 yards is far enough that a poor ES will cause vertical stringing. If the ES is good, do a ladder test and find a "Sweet spot". You may have a load at the "Sour Spot". And yes, of course you need a Chrony. You know that for a fact because SunShine said you don't.
 
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