What does this grouping mean?

aushunter1

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Nov 16, 2012
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Well after looking at your original post I was under the impression that those groups were the best you were getting.
That was until you showed us the whole picture which being shown earlier would have also helped!!

So, I don't think there is an actual problem, well apart from what you have outlined with the scope height & cheek weld not being good.

I just think you haven't fully explored or finished your load testing.

What you are showing in common when going through ladder testing.

Here is something I posted on another thread that was all about seating depth, have a look at how much the group is affected by the change of CBTO adjustment.

These where the changes I made after going through the powder range at 10thou

1579918792350.png

And this is the 10thou target
thumbnail_20200125_133539-1.jpg

I was rushing trying to get a load for an upcoming trip & went with the 57gr @ 5 thou off the lands group knowing my longest shot was going to be 200 metres on this trip.
I still haven't finished this load development yet, I need to go back & no do some incremental powder changes to see if there is an improvement or not.
 

jgs8163

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Sep 27, 2011
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I know! There's lots of suggestions here. I had planned to get lower scope rings or a Velcro cheek weld to see if it helps. I'm pretty sure it would at least a bit!
PM me if you want to discuss more. Let us know how it works out!
 

jgs8163

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I’ve watched guys fight cheek weld and not pay much attention to it. I was one of them. Not anymore, I recognize it immediately and have helped many cure their issue while witnessing their frustration at the range. Anyways.... get rid of the obvious and known issues before chasing unknowns. Good luck Ryan.
 

Ryan Tockstein

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Apr 28, 2019
Messages
73
Location
Sandy, UT
Well after looking at your original post I was under the impression that those groups were the best you were getting.
That was until you showed us the whole picture which being shown earlier would have also helped!!

So, I don't think there is an actual problem, well apart from what you have outlined with the scope height & cheek weld not being good.

I just think you haven't fully explored or finished your load testing.

What you are showing in common when going through ladder testing.

Here is something I posted on another thread that was all about seating depth, have a look at how much the group is affected by the change of CBTO adjustment.

These where the changes I made after going through the powder range at 10thou

View attachment 171432

And this is the 10thou target
View attachment 171433

I was rushing trying to get a load for an upcoming trip & went with the 57gr @ 5 thou off the lands group knowing my longest shot was going to be 200 metres on this trip.
I still haven't finished this load development yet, I need to go back & no do some incremental powder changes to see if there is an improvement or not.

That's really interesting how large an impact just 0.010 seating depth has on grouping. I tried sorting out my bullets on my last round of loading to weight first, then to bullet base to ogive. There didn't seem to be much correlation between the weight and BTO on the bullets. So, I threw out the outliers in the BTO measurement, and loaded the bullets that were closest in weight and BTO.

I'm using a Lee hand press and Lee dies. So, of course they're not top of the line, but I think I do a pretty good job with them anyway. The closest I was able to get on my CBTO with these was 2.730-2.732. I don't know how much of a difference a couple thou would make, but it doesn't seem like it would make a huge difference.

I'll load another 20 rounds at some point with one of my better loads, maybe the 57.5-57.8 and 59.6-59.9 with a few different seating depths.
 

Ryan Tockstein

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Apr 28, 2019
Messages
73
Location
Sandy, UT
I’ve watched guys fight cheek weld and not pay much attention to it. I was one of them. Not anymore, I recognize it immediately and have helped many cure their issue while witnessing their frustration at the range. Anyways.... get rid of the obvious and known issues before chasing unknowns. Good luck Ryan.

I'll probably pick up a stock ammo pouch or something to get a good cheek weld tomorrow, test it out on a good load and we'll see how it goes!
 

aushunter1

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Nov 16, 2012
Messages
441
Location
Sydney
That's really interesting how large an impact just 0.010 seating depth has on grouping. I tried sorting out my bullets on my last round of loading to weight first, then to bullet base to ogive. There didn't seem to be much correlation between the weight and BTO on the bullets. So, I threw out the outliers in the BTO measurement, and loaded the bullets that were closest in weight and BTO.

I'm using a Lee hand press and Lee dies. So, of course they're not top of the line, but I think I do a pretty good job with them anyway. The closest I was able to get on my CBTO with these was 2.730-2.732. I don't know how much of a difference a couple thou would make, but it doesn't seem like it would make a huge difference.

I'll load another 20 rounds at some point with one of my better loads, maybe the 57.5-57.8 and 59.6-59.9 with a few different seating depths.
As you can see even 0.005 made a big difference!

You hear so many people saying seating depth has little to do with accuracy but they are probably the people who don't even have the equipment to measure so just discard its validity!

You definitely have some things to look at it but I would also try the different seating depths for a starting point.

Good luck with it :)
 

KENNETH R BRACKENBURY

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Jul 14, 2018
Messages
41
Location
Missouri
Try what everyone says. Also check primer seating depth. Take scope off and base and start over. Check scope base for damage same with rings. Clean internals of bolt. Let someone else shoot your're rifle.
We go through all of those problems with fellow shooters. Most of the time its scope/base or mounting screws. Once or twice its been the stock.
Long story shorter.......Check everything and start over................Good luck.
 

Swordslayer1

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Joined
May 26, 2013
Messages
15
I'm no expert but I had a similar issue with a Tikka T3. I believe that I was shooting way to quickly and the barrel was heating up too much. I then allowed the barrel to cool between subsequent shots and my groups greatly improved.
 

Alibiiv

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iii
Yep, I see this as a sign of warm barrel/pressure point on stock. Now it may not be that, but if you can't slide a pretty thick card between barrel and stock, it may be binding when warmed up.
I use a once folded over dollar bill, and float my barrels back to within 4 inches in front of the recoil-lug. My experience from groups such as those that you have posted has occurred due to a featherweight barrel from heating up
 
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Chase723

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Nov 22, 2009
Messages
270
My understanding in load development is that you start about 10% low of the max charge (in this case 62 gr max) and increase charges by 1% of max, which would be 0.6gr. is this wrong??

I'm not sure what people mean by checking parallax. I use a vortex viper HST scope oh, so my parallax is always adjusted to the distance I'm shooting. All I know about parallax is that I need to have my eye close enough to the scope to eliminate any shadow around the edges and make sure that my crosshairs don't shift when I move my head. I do always try to make sure that my eye is centered in the scope and in the same spot I shoot.
Paralax is the distortion of the image caused by refractive error due to the image of your reticle and the image of the target not being on the same plain of focus. It has an effect even at 100 yards. Prior to shooting make sure your diopter is set up correctly and that you have a crisp reticle picture. Then when you get set up to shoot make sure that you use the paralax knob on the side to adjust the image clarity until it’s perfectly crisp and the center of the reticle doesn’t move when you move your head/eye. If you have any paralax error , it’ll be magnified by inconsistent head position/cheek weld/sight picture.
 
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okie man

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Dec 21, 2013
Messages
683
Here’s something to look at. Set your gun up like you shoot it, head down on cheek rest and have someone try the dollar bill test! You’ll find testing with a rifle resting in a gun vice minus the weight of you resting on it will show no contact . Put a bipod on the tip of the fore end and lay on it , totally different story. Especially with injected plastic stocks. I removed a bunch of the barrel channel and epoxied a piece of graphite arrow shaft in a vanguard stock trying to keep it free floated.
 

Jon Bischof

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Oct 25, 2002
Messages
111
Location
Paragould, AR
Yep, those dollar bills may not slide so easy after you have shot half a box of cartridges. Try it on a warm barrel while your cheek is resting on the stock. Might be tight then.
 

lgordee

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Jul 10, 2012
Messages
386
Seating depth or powder charge. Do you know what a ladder test is? ( No disrespect)
Great example of a ladder test and good of you to point it out. The problem that can arise with some ladder tests, is when either the rifle or the person steering the rifle, can't shoot accurately. A ladder test is meaningless then. If the rifle doesn't group @ 100 yards, and especially if the group exhibits a lot of vertical, a 300 yard or beyond ladder test is pointless. From what I'm reading in this thread the OP needs to forget about a ladder test. I could be entirely wrong, but my reason for utilizing a ladder test is limited to identifying a "node" and then centering my powder charge in that node. Once I have that determined, I work on seating depth. Others may see things differently and that's perfectly fine. Opinions are like noses, everyone has one and is entitled to it. 🤓
 

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