Group Pattern Question

[Csbc4fun]

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!

Groups make no assumptions they tell the truth…. If you want to you can check the kitchen sink of ideas (I recommend you don't change anything but seating depth) start lengthening your seating depth in 0.003" increments 3-shots at a length for about ten steps. You may find a sweet spot. When I test my 6.5 CM my groups move left, right, bigger, smaller, I even got double groups separated by two inches one time. Then there it is,"0.250 or less". Enjoy the exercise and keep'em small.

 

[Csbc4fun]

Groups make no assumptions they tell the truth…. If you want to you can check the kitchen sink of ideas (I recommend you don't change anything but seating depth) start lengthening your seating depth in 0.003" increments 3-shots at a length for about ten steps. You may find a sweet spot. When I test my 6.5 CM my groups move left, right, bigger, smaller, I even got double groups separated by two inches one time. Then there it is,"0.250 or less". Enjoy the exercise and keep'em small.

To clarify I meant move the seating depth out away from lands, shortening your overall length 0.003" per step.

 

[Coues110]

Oh man no pride there at all brother. It could be me I shouldn't rule that out, but normally I'd know if I pulled one like that and easily call it right away without even needing to see it too. I am single feeding and I will take the suggestion to shoot off a bag this next time. This is the first rifle I've ever had with such a light barrel and non-free floated. I truly appreciate the help brainstorming so I can make the most of my next time out to shoot and figure this out.

I've heard that if the action is pinched and doesn't return to battery in the stock that can cause this, but it's more of a double grouping than an odd flyer. One thing I've heard is to try is to grease the receiver and lighten the torque on the action screws. Every once in a while I get a flier like that, but maybe 1 in 12 shots and not quite so far out of the group. I wonder if I'm pulling it too and don't think so. I always check concentricity and use anything over 3 thou out to foul the barrel after cleaning. Check to see if you can fit a bullet in the neck of a fired piece of brass. It should pass easily into the neck. If not you may need to turn necks or lighten neck tension. The theory is that the neck grabs the bullet on the way out of a tight neck and throws it out of concentricity.

 

[dashender7]

Hi everyone OP here - I went on a half day round trip to the next state over to pick up some farming equipment with a buddy. I've got some catching up to do! I've started reading through all of the posts and I will study all of the great thoughts tonight and report back with any additional info I can for clarification etc. in my next post. Thank you all so much, what a great community!

 

[nealm66]

I've heard that if the action is pinched and doesn't return to battery in the stock that can cause this, but it's more of a double grouping than an odd flyer. One thing I've heard is to try is to grease the receiver and lighten the torque on the action screws. Every once in a while I get a flier like that, but maybe 1 in 12 shots and not quite so far out of the group. I wonder if I'm pulling it too and don't think so. I always check concentricity and use anything over 3 thou out to foul the barrel after cleaning. Check to see if you can fit a bullet in the neck of a fired piece of brass. It should pass easily into the neck. If not you may need to turn necks or lighten neck tension. The theory is that the neck grabs the bullet on the way out of a tight neck and throws it out of concentricity.

My brother had a savage 111 6.5-284 that would throw 1 in 10-20 out about an inch at 200. He was wanting to use it in hunter class competition at 600 yards and at my recommendation he took it to a gunsmith and had a new stock and proper bedding and the flyer went away. Could have been other things and maybe I got lucky. Someday I'd like to be brave enough to try and bed a stock but I fear I don't have the patience or attention to detail

 

[6.5 Remington]

If you've never owned a weatherby rifel before!!!! Here's a little insight from the 8 that I own !! It will drive you nuts ! I've been shooting for 40 + years and I shoot so many different caliber's and manufacturers !! But a weatherby rifel still befuddles me !!!!!!! You can shoot 2 rnds in 1 hole but the darn thing will throw that 3rd round almost every time!! But the next round will come back to the group!! What ever is going on I haven't quite figured that out I have done everything under the sun and they still won't shoot that 3rd round !! I've been a reloader for almost as long and have some amazing results but these weatherby rifels have a niche that you just can't overcome!! So just keep doing what your doing and don't worry so much about a certain round in your sequence !!!!! It's going to happen

 

[dashender7]

Okay I caught up. Lots of things to consider, this is exactly why I came here - for great ideas from guys with more experience than me. Some things are great ideas but I may be able to eliminate because I didn't provide proper clarification or the right context in my original post.

Out of all of the responses this one from just before I went to make this post really intrigues me so I have to respond to it right away:

If you've never owned a weatherby rifel before!!!! Here's a little insight from the 8 that I own !! It will drive you nuts ! I've been shooting for 40 + years and I shoot so many different caliber's and manufacturers !! But a weatherby rifel still befuddles me !!!!!!! You can shoot 2 rnds in 1 hole but the darn thing will throw that 3rd round almost every time!! But the next round will come back to the group!! What ever is going on I haven't quite figured that out I have done everything under the sun and they still won't shoot that 3rd round !! I've been a reloader for almost as long and have some amazing results but these weatherby rifels have a niche that you just can't overcome!! So just keep doing what your doing and don't worry so much about a certain round in your sequence !!!!! It's going to happen

The reason is that Robert explains repeated experience - with Weatherby rifles in particular - across multiple rifles by that manufacturer it seems - exactly what I described experiencing with this Weatherby. That is: first 2 shots in a group starting from a cold bore on the 1st shot are nails together in almost same hole, then 3rd shot crazy flyer, then 4th shot back touching the first 2. Same specific sequence.

For me, this rifle shoots some decent groups repeatably under 1MOA at several charges and seating depths (and then also some poor rather scattered normal out-of-node groups at other charge and seating depth combinations),

But it is particularly and singularly when I get these otherwise tiny groups (I had the same thing happen at a way slower 2,600 fps node with H4350 before going to RL-26) that I see a single crazy flyer worse than anything else I shoot, where I feel confident I made a clean consistent shot. So the crazy flyer goes with the otherwise tiniest groups, and happens repeatedly specifically on the 3rd shot in a string when starting that string from a cold bore.

I promise I'm not crazy, and I don't have too much pride to still think it could just be me, but Robert seems to be confirming just what I'm saying (unless this is some kind of mis-timed April fool's joke Robert!)

That said, tons of other awesome advice here, more than I can possibly acknowledge but I'm taking notes on everything from trying carefully bumping powder up slightly or backing seating depth off 3 thousandths at a time to changing shooting platform to checking my technique against a different known rifle, to checking spec on action screws and finally maybe bedding issues (and more than that too!). Gonna sleep on it and hopefully get a chance to load up some more rounds and shoot tomorrow or Saturday to see what we can figure out.

 

[dashender7]

If you've never owned a weatherby rifel before!!!! Here's a little insight from the 8 that I own !! It will drive you nuts ! I've been shooting for 40 + years and I shoot so many different caliber's and manufacturers !! But a weatherby rifel still befuddles me !!!!!!! You can shoot 2 rnds in 1 hole but the darn thing will throw that 3rd round almost every time!! But the next round will come back to the group!! What ever is going on I haven't quite figured that out I have done everything under the sun and they still won't shoot that 3rd round !! I've been a reloader for almost as long and have some amazing results but these weatherby rifels have a niche that you just can't overcome!! So just keep doing what your doing and don't worry so much about a certain round in your sequence !!!!! It's going to happen

Also yes I forgot to confirm this is my very first Weatherby although it is about the 8th rifle I've loaded for over the past few years since I started reloading and I have never seen this. I'm similarly befuddled and I sure hope you're not just fooling with me!

 

[dashender7]

2735 fps with 143 ELD-X and RL26 out of a 24" bbl should not be close to excess pressure unless you are jammed. You should be ok to at least 2900 fps - which is roughly 63kpsi.

I agree with the above I noticed my 2735 fps was low by at least 100 fps for 26.0gr of RL-26 with this pill according to Hornady data. I may try bumping powder by .2 or .3gr in a future test.

I never plan on a gun shooting a specific powder, sometimes it works sometimes it doesn't. I usually have 2 or 3

Makes sense. So far I tried H4350 and interestingly also found that to be slower than published data by about 50 fps and found one very similar grouping load to the one in question in this thread but at only 2600 fps

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 still agree the above could be a possibility but I want to say in all possible humility I do not think it is mechanics as the wild flyers only happen specifically on these otherwise amazing sub .25 MOA standout groups and amazingly on shot 3 of a string.

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.

I will certainly do the above as suggested once trying a couple more things suggested here.

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

The way these Weatherby Vanguards are made it is almost certainly not free floated the stock has to be contacting the barrel but I think that might be by design? Not sure though. I have no experience bedding a stock, this is my first rifle with a lightweight barrel and that is not clearly free floated.

Shoot a 10-shot group before you make any changes.

This is daunting to me with a barrel that gets very hot so quickly but I wont rule it out - do you truly suggest this for such a thin barrel rather than for something like an F class or heavy barreled rifle?

 

[dashender7]

I've heard that if the action is pinched and doesn't return to battery in the stock that can cause this, but it's more of a double grouping than an odd flyer. One thing I've heard is to try is to grease the receiver and lighten the torque on the action screws.

I have seen the double grouping on some other loads yes. I could see my action screws being too tight as I did remove the stock to adjust the trigger. I will check torque specs.

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.

So many good suggestions here I'm going to go through it and use it like a checklist thank you. I am using a ProChrono so no Magnetospeed or chrono connected to barrel. Flyer seems to be shot 3 of a string. Off to the right yes.

My view is work on good shooting form and bed the rifle in a better stock, good luck.

Yes I will see if I can confirm with a different rifle and a different stock is not out of the question as I think there are more options for these Weatherby rifles these days.

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.

Your points about the assumed pressure signs are well taken. I can recall reading similar things elsewhere so bumping powder up slightly and slowly is one of the things I may try. Good point about higher pressure should correlate with higher velocity, that seems to make sense. Completely agree the fps I'm getting seems a good bit slower than expected. Any sense of how accurate a ProChrono is or whether it reads slow? I will also pay more attention to bolt lift - I have been forgetting to note that as an indicator of pressure. Thank you for all of the great thoughts.

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?

I do agree with the logic here in terms of feeling like such a relatively small fps difference alone shouldn't show up at 100 yds unless something else were connected with the fps difference. The group I'm seeing is with about a 12 ES. The barrel now has about 140 round on it and the pictured group was one of the last couple I shot.

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.

I was quick to blame myself the first time I saw this group pattern and sequence with this charge in spite of the fact that the flyer shot felt perfect breaking off but when I confirmed it a second time including pattern and sequence that gave me great pause as normally I can call even a slight pull. I'd actually prefer to believe it was just me pulling a shot. Lots of suggestions here including having my buddy shoot a group for me with it which could always still confirm you're right! Also I appreciate your perspective on the cold barrel there's some logic to it for sure.

To clarify I meant move the seating depth out away from lands, shortening your overall length 0.003" per step.

Yes got it thank you. I do think seating depth is worth trying here I want to say it is right near top of my list after I double check all of my torques and shooting mechanics.

 

[QuietTexan]

This is daunting to me with a barrel that gets very hot so quickly but I wont rule it out - do you truly suggest this for such a thin barrel rather than for something like an F class or heavy barreled rifle?

Yes, take your time a shoot it over a time period that allows the barrel to remain at a decent temp. One shot every 3-7 minutes. My pencil barrel 30-06 takes longer to shoot groups than my 300 RUM because of the barrel, but in the end the hour it'll take is worth it if it helps you avoid taking the entire rifle apart chasing a mechanical issue. And you can also overlay groups - don't change anything (specifically scope settings), and you can draw the holes of several targets together onto a fresh target to aggregate a 10-shoot group without actually having to shoot ten consecutive shots.

What you're trying to do is see if the "two together" are consistently landing compared to other "two together" groups, or if those two shot groups are orbiting around your point-of-aim (POA). If the two-shot groups are consistently grouping and the outlier single shots are grouping together, it's most likely something mechanical - a loose screw or cracked bedding or scope problem, etc. But if the clusters are moving in relation to POA, what you're seeing in the 10-shot group is the true group size.

This is an overlay where apparent "fliers" are actually within the mean radius of the overall aggregate group. There's no problem here, the rifle is just a 1" gun in reality, and not a .25" gun like Group 1 makes it look. Anything less than 10 shots is statistically irrelevant, and only provides negative confirmation that that particular load's aggregate group "can't be any better" than the spread, but does not give confidence that the rifle is capable of that small of a group size consistently.

To expand on the negative confirmation thing - when testing a new barrel tuner, a common method is to shoot just two shots at each setting (even though I just said less than 10 is statistically invalid). As the groups close - you shoot more at the better settings. Across the top row you see the two shot groups close then open again. You can rule out the settings where the two shots aren't touching, and then start shooting more (5-10 shot strings) at the initially more promising settings so that you don't waste rounds on groups that you know aren't going to be better than those first two shots. (please don't think I'm saying to do this test on a hunting rifle, this is a benchrest/ competition method I'm using to illustrate my point).

This is what ES is to velocity, but in the context of group statistics. Normally ES is a weak indicator because it ignores every data point in the population other than the highest and lowest, so it's based on the least possible amount of information. It can't give any confidence about what will happen in the future (predicting the next shot), but if it shows a range that is too wide you can rule out that load as not being capable of placing the next shot correctly. If you need to be able to hit 4" at 400 yards every time, then a load that puts the first two shots 8" apart at 400 yards obviously isn't going to cut it.

On the predictive side then, if it shoots the first two shots 3" apart, there's still a large likelihood that Shots 3-5 aren't going to fall into the middle of those two, and the group will be larger than 4". So you have to shoot more shots to be sure. If the load printed a 4" group at 400 yards for 5 shots.... there's about a 34% chance it'll be under 4" next time. If the load printed a 1" group at 400 yards for 5 shots.... 90% chance it'll be under 4" next time. (roughly, based on terrible napkin math looking at a z-table )

Source of pic/ great read on group sizes:

Precision & Group Size – Statistics for Shooters Part 3

This article is going to dive into the most effective ways to quantify the precision of a rifle and...

precisionrifleblog.com

(Random aside - an "acceptable range" for ES could easily be anything from 30FPS to 300FPS, depending on application and range. There is no broad-based maximum acceptable ES, just like there's no maximum acceptable group size - all that matters is that the rifle does what you need it to. That might mean chasing a .25" group at 100 yards, that might mean accepting an 8" group at 400 yards. Define the goal first, that will drive what you really need to chase in terms of muzzle velocity and group size statistics.)

 

[Backcountry sports]

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!

Is the stock touching barrel

 

[nealm66]

I haven't had a problem with flyers with vanguards. Your group without the flyer will be where you end up after you figure out the problem

 

[L.Sherm]

I've never had to shoot 10 shot groups in my hunting rifles to get were I need to be, if 3 shot groups will repeat your good to go.