Group Pattern Question

dashender7

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Oct 22, 2021
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Well the good news is that it looks like you’re there. I’d stay with that load until I figured it out. How many firings on the brass and are you keeping them sorted. Very unlikely but I’ve had oddball neck tension create a problem
Load dev has been with 2x through 3x always sorted by firing x. I'm going to assume it is me or my shooting platform for now and try another round of groups from a bag around that charge.
 

Doom2

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I was seeing patterns not too long ago shooting my 308 off a bench and could not figure out what was happening. Out of desperation I went to some targets and noted it seemed to happen on load development shooting round robin and seemed consistent with moving away from the gun then returning. I went back to the 22LR and found two issue.

If you are seeing this as typically horizontal and consistently in one direction you may not be seating the rifle consistently in/on your shoulder, especially if you are moving between shots. On recoil the butt end of the rifle moved differently.

Another possibility is that your trigger release is too quick.

Don’t know if this will help but good luck.
 

Hard rock

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IMHO, I'd get someone you know has equal or better shooting ability to give them a try once you're confident all ammo/rifle variables are ruled out.
The first thing I would do is check the float or make sure the barrel is floated too me it looks like the barrel is touching on one side of the stock float it all the way back too the receiver being a light weight barrel it doesn’t take much too throw the harmonics off the group looks too good too be the shooter
 

RYEWSKY25284

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I know. But there is a direct relationship between velocity and pressure for a give bullet, powder burn rate, and barrel length.

My comment was specific to the 143 ELD-X, 24” and RL26 out of 6.5 CM. I would expect to just start seeing pressure signs with H4350 at that velocity (2735 fps), but not a slower burning powder like RL26.

Just wanted to let the OP know that it’s possible he might possible go slightly higher on powder charge to solve his issues. Carefully of course.
one of the OP's comments was he was already seeing slight signs of pressure.
This might make it unsafe/unwise to move up in powder charge.
JMHO
 

emp1953

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Sep 29, 2013
Messages
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I've seen several things cause a single flyer out of every string.
First I Eliminate me. Let someone else fire it, see if they get the same results.

Untorqued or over torqued action screws.
Loose/untorqued scope base screws.
Loose/untorqued scope ring screws.
Defective scope. Last thing to try is to swap in ANY scope you have to see if it changes things. I've
had new scopes out of the box with problems.
Try single feeding your rounds, don't use the magazine.
Next I'd completely remove the bipod for a trial. Keep everything away from the barrel during firing.
What type of Chronograph are you using? I've seen magnetospeeds cause strange things on thin barrels.
Is the flyer always the same shot in the string? Like always the last shot?
Is this old brass or new brass?

Is the flyer always off to the right a similar amount 2moa? If it is this should be fairly easy for you to nail down. It
will have to be something mechanical, changing with recoil or heat.
Does the barrel heat up quickly? Do you only see this when the barrel is warm?

Is the flyer always the same shot in the string? Like always the last shot?
Is the flyer always off to the right a similar amount 2moa? Shooting a bug hole then a flyer is frustrating but it will be fixed. This should be fairly easy for you to nail down.
 
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73driver

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Aug 24, 2011
Messages
385
I was seeing patterns not too long ago shooting my 308 off a bench and could not figure out what was happening. Out of desperation I went to some targets and noted it seemed to happen on load development shooting round robin and seemed consistent with moving away from the gun then returning. I went back to the 22LR and found two issue.

If you are seeing this as typically horizontal and consistently in one direction you may not be seating the rifle consistently in/on your shoulder, especially if you are moving between shots. On recoil the butt end of the rifle moved differently.

Another possibility is that your trigger release is too quick.

Don’t know if this will help but good luck.
I agree with Doom's post. 20 years ago doing extensive load development with a 30-06 I noticed one flyer usually blew up my groups. Over the years I improved my technique but I am still working on my consistency. The attached photos show two cold bore groups at 200 yards from a 6.5C Vanguard Kings Desert shadow camo rifle with a fluted barrel that I have been working with this last year, the first shot of the session is the flyer to the right of orange dot and the next two shots right on. After an hour or so shot the second group, a two shoot group, and taking care to use good form delivered results. The third group at the 5:00 o'clock position on the 2 inch orange dot was shot several days later out on a cold bore rifle and confirms the rifle shoots if I do my part. This rifle came with a cheap plastic stock and did not shoot consistently at first. Putting the rifle in a B&C stock helped but still so so groups. After bedding the rifle in the B&C stock it finally delivered very good groups when I did my part. My view is work on good shooting form and bed the rifle in a better stock, good luck.
 

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Stammster

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Houston, Texas
one of the OP's comments was he was already seeing slight signs of pressure.
This might make it unsafe/unwise to move up in powder charge.
JMHO

Yep, saw that comment also...but original post was more around being at 46gr and concerned about possible pressure. Then he clarified later. But here is still my take:
1.) Soot around necks happens with RL26. In fact it gets worse at low pressure, not high pressure as the brass doesn’t seal properly.
2.) Depending on the firing pin and boltface hole size, cratered primers are not a good indicator of pressure. Especially in Rem actions. Not sure about yours.
3.). Depending on primer type, size, and mfg, flat primers are not always a good indicator of pressure. In fact, all my WLR primers using RL26 are flat...even those at <50kpsi.

Case capacity just effects the pressure vs charge weight. If he thinks the Lapua brass has lower capacity, then he should see higher velocities and pressures for a given charge weight - not just higher pressures.

I realize every gun is different...but come on. 2735 fps with RL26 in a 24” bbl with 143s seem slow to me and I’m sure others will agree. Thus the comment I believe the OP is possibly misreading pressure signs. Got to be sure of the chrono reading though.

When I am looking for a good shooting node, I also often see what he sees. 3-4 in one hole and then 1 flyer. On the chrono, the flyer turns out to be 15-20 fps slower. Taking it out of the sweet spot to a different POI. Increase charge weight by 0.2-0.3 gr and see what happens. He’s not going to blow his face off.

In bolt guns, bolt lift is a much better indicator of pressure. No mention of that.
 
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L.Sherm

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15-20fps is only .5 at 500 yards. E.S at 100 yards means very little unless its extreme even 1000 BR guys have double digit E.S target tells the story. If the gun isn't bedded id start there then make sure barrel has clearance and eliminate all mechanical things before I would start messing with load.
How many rounds down your barrel?
 

tony d willIiams

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Jan 20, 2019
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San Bernardino Mountains
I'm seeing a pattern repeating shooting groups.

6.5 CM Weatherby Vanguard "Meat Eater" with 24" spiral fluted light barrel. No modifications. About 140 rounds on the rifle now. 143 ELD-X with Lapua brass CCI 400 small rifle primers RL-26 2,735 avg. with about a 12 ES. Maybe the very beginnings of light pressure near top of published powder around 46.0

I can back off powder and get about .8" groups consistently, but I'm wanting to chase these almost tiny groups.

Pictured below is at 100yds. Have seen similar results at 200yds with the expected group size comparably.

4 or 5 shot groups with small cluster and one bad flyer up to 1.5" to 2"" out of the group that are otherwise all touching. Pictured below is the worst one. Unless I'm crazy, I feel like the wild one is shot 3 after the first 2 starting with a cold or cooled down barrel. I also might be waiting longer after that flyer for the barrel to cool before shot 4 thinking the barrel is warming up too much. Haven' been able to confirm again yet.

Hoping for ideas and insight to consider as I troubleshoot load development. Dumb to think I'm on to something good with this load given the bad one that happens in every group? Barrel heating up or wrong powder charge? Where might I go from here? Thanks in advance!

pUcuTma.jpg
 

Teri Anne

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May 24, 2021
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189
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Wisconsin
I'm seeing a pattern repeating shooting groups.

6.5 CM Weatherby Vanguard "Meat Eater" with 24" spiral fluted light barrel. No modifications. About 140 rounds on the rifle now. 143 ELD-X with Lapua brass CCI 400 small rifle primers RL-26 2,735 avg. with about a 12 ES. Maybe the very beginnings of light pressure near top of published powder around 46.0

I can back off powder and get about .8" groups consistently, but I'm wanting to chase these almost tiny groups.

Pictured below is at 100yds. Have seen similar results at 200yds with the expected group size comparably.

4 or 5 shot groups with small cluster and one bad flyer up to 1.5" to 2"" out of the group that are otherwise all touching. Pictured below is the worst one. Unless I'm crazy, I feel like the wild one is shot 3 after the first 2 starting with a cold or cooled down barrel. I also might be waiting longer after that flyer for the barrel to cool before shot 4 thinking the barrel is warming up too much. Haven' been able to confirm again yet.

Hoping for ideas and insight to consider as I troubleshoot load development. Dumb to think I'm on to something good with this load given the bad one that happens in every group? Barrel heating up or wrong powder charge? Where might I go from here? Thanks in advance!

pUcuTma.jpg
Well here is another of one of those mystery fliers that nobody can understand. Everyone wants to blame something else for what can simply be attributed to one bad shot out of 5. Rifles do not normally decide to shoot a flier randomly, scopes do not suddenly change their zero and miraculously return for the next 4 shots. There are only two reasons that can be attributed to this situation. 1 - a bad round, not quite the same as the others, but that will not repeat itself on a regular basis with care in loading. 2 - Face facts, when the rifle discharged it was pointing exactly where that flier went. We are not talking a big disparity from the group here, a little parallax issue, the squeeze of the trigger set the rifle off a millisecond before you were actually ready. The slightest little difference can make the biggest errors. I am also not a big fan of the supposed cold barrel shot. All of my rifles will shoot a 5 shot group at 1MOA or less when fired with a cold to hot barrel in around 2 minutes.
If you miss that all holy first shot at your Animal of a lifetime are you going to ask it to stay put until your barrel cools?
 
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