Group Pattern Question

dashender7

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Given a light barrel that’s not floated it’s highly likely this is not a quarter MOA rifle and chasing that goal my be the problem here. I assume this is a hunting rifle and if so, less than MOA is more than sufficient.

I would back off and take the .8 MOA.

You are right. I did some quick research on the Weatherby Vanguard to confirm what I thought as well which agrees with what Doom2 is saying here. The Weatherby Vanguard with factory stock is definitely not free-floated and not intended to be free-floated by design, and Weatherby confirms this. My impression is to agree this seems common for very light barreled hunting rifles, which is what this is. Bedding a rifle like this is something I have no experience with and know nothing about. Is that entailing just trying to get a more consistent purchase with the action and stock around the recoil lug primarily, or along the barrel as well?
 

dashender7

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Alright here is my update:

Yesterday (Sunday)( I made it to the range to shoot the Weatherby Vanguard 6.5CM some more. Unfortunately I did not have time beforehand to work up new loads based on the various great suggestions here in this thread before this trip to the range.

I already posted noting that I re-mounted my stock to exact factory torque specs, and re-mounted my scope and hardware to their factory specs as well before going to the range. I made a previous trip to the range on Saturday where I took one shot to confirm and rough-adjust zero after re-mounting before working with a different rifle.

However I did have 12 rounds in 4 sets of 3 to already loaded up to shoot this weekend based on my study of all of my previous groups. Some characteristics of the loads I had already worked up to test did end up having a lot of overlap with several of the suggestions here in the thread. So I went ahead and shot with those.

All 4 groups of 3 had the following in common:

Lapua 3x brass trimmed to spec
CCI #400 small primers
RL-26 powder
ELD-X 143gr
CBTO 2.218 (based on previous seating tests I felt backing off a few thousands put me in a safer spot in the seating depth zone for the zone of powder charges I wanted to try)

The only variable was powder charge grains (all RL-26).

In addition, I ditched the bipod/rear squeeze bag setup and shot prone off a backpack on the ground with a rear squeeze bag. I haven't done a lot of shooting this way recently and have never done any part of load development this way. I had a few shots to practice from another hunting rifle before getting started with this rifle, but felt I was still getting the feel for it through the session. Shot at 100yds this time. There was a little more wind - very sporadic half-value - than I'd like to have on a day like that but not too bad.

I waited at least a minute between shots and 5 between groups and I did switch back and forth working with another rifle off the backpack in between. I single-loaded all. (If you're in the group that says don't wait between shots to let the barrel cool, I do plan to test with more rapid strings later on - just trying to eliminate some variables here). The other rifle I worked with yesterday (A Ruger American 6mm Creed) shot some nice groups too.

Below are the results from the 4 groups of 3 (I know 3 shot groups make some cringe but this is a hunting rifle and this was intended to be final confirmation of seating depth and powder charge where I've already seen good groups with 4 to 5 rounds).

I do plan to confirm and overlay additional groups as per suggestions of several here including the detailed advice of QuietTexan in order to de-facto produce groups made up of more rounds). I'm a little messed up on overlaying these with previously fired groups due to re-mounting my whole setup and having to re-zero.

The original intent here when I loaded these (again, before the suggestions from this post) was to re-confirm both seating depth I thought looked best previously and also re-confirm powder charge for mildly cold circa 40 degree conditions and eliminate charges that weren't as good.

Unfortunately my chrono missed a reading on every group except the 2nd one (the best one) as it was partly cloudy with some shadows going on.

45.5gr: 1.19" group with mostly horizontal. Unfortunately I know I pulled one right a little as I was getting used to shooting from the bag still and flinched it a bit. I think this would have been a better group but no way to know!
???
2,732
2,721
45.7gr: 0.54" group (pictured below). Overlays / centers perfectly with above group minus the above pulled shot.
2,737
2,732
2,726
45.9gr: 1.04" group with mostly vertical. Overlays / centers well with above groups
2,732
2,743
???
46.1gr: 0.92" group I'd describe as diagonal. Overlays well with above groups (as in not much change in POI).
2,732
???
2,732

Note the temperature dropped probably 8 to 10 degrees over the course of the shooting session and I did have my ammo box open next to me the whole time so it was probably cooling the sitting rounds throughout and I don't know how else to account for the way velocity stayed so nearly consistent across .6 grains of powder as I went from group to group going up in powder.

I feel my groups would have been a little better if I were better at shooting off this backpack position as I didn't feel 100% confident I was doing my part as solidly as I'd like throughout.

This correlates well with previous experience that this zone of seating depth with about 45.7gr of RL-26 produced good 1/2" to 3/4" 4 shot groups.

Here's that best group - I hope to post some kind of overlay shots in the near future - and I welcome any further comments and thoughts from anyone:

uvUOj5ul.jpg



Below is a 3 shot "confirming" group I fired with my Ruger American Predator 6mm CM the in the same trip, also off the backpack prone (confirming previous best 5 shot group and seating depth which happens to be 41.3gr H4350 at 2.214 CBTO with Hornady 103 ELD-X, Hornady 3x brass, CCI standard large rifle primers and I'm seeing about a 25 ES with this load on the larger groups which is more ES than I'm used to getting with my better loads).

In the same spirit as with the Weatherby and the advice from members here to leave no stone unturned, I had also re-mounted my whole setup on this Ruger rifle with my new torque screwdriver and roughed in my zero with 1 shot previously, hence being off from zero on this one too:

mZKcejtl.jpg
 

nealm66

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washington
Looks like the flyer is gone. I’m guessing with a better, more consistent rest, you’re probably punching a nickel size group. I shoot off a Caldwell front rest and a bag when I’m doing load work to help eliminate stock variations. There might be a bipod mount that grabs a little more of the stock that might help eliminate the flyer like the bag did.
 

QuietTexan

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My nickle says it was ultimately a problem in the rings/ base and you fixed it by torqueing it all. The almost 2" of lateral in the first group almost certainly had to be something drastic. Glad it's tightened up for you 👍 As you shoot more groups and overlay them, the center comes out so you can set up an MPBR, and then you're off and hunting and filling the freezer.
 

dashender7

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Looks like the flyer is gone. I’m guessing with a better, more consistent rest, you’re probably punching a nickel size group. I shoot off a Caldwell front rest and a bag when I’m doing load work to help eliminate stock variations. There might be a bipod mount that grabs a little more of the stock that might help eliminate the flyer like the bag did.

nealm66, thanks for hanging in here with me throughout with such a helpful and encouraging disposition! I'm going to look into the Caldwell rests and bags or something like it for load dev in the future.

I did just purchase an Eberlestock backpack mounted front rest which is on its way and I'm thinking with the backpack packed better that will be an improvement and something I can maybe use in the field too. I think the bipod may be getting retired for me at least for now.
 

dashender7

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My nickle says it was ultimately a problem in the rings/ base and you fixed it by torqueing it all. The almost 2" of lateral in the first group almost certainly had to be something drastic. Glad it's tightened up for you 👍 As you shoot more groups and overlay them, the center comes out so you can set up an MPBR, and then you're off and hunting and filling the freezer.

Thanks QuietTexan. Your main writeup a ways back in this thread educated me greatly and is something I'm going to come back to in the future often I think for reference. Thanks for taking the time to give the input particularly on group overlay.

One question I have for you in from your main post in your illustration is that you advised not to do the 2 shot method early in load dev to eliminate the clearly least useful loads when loading for a hunting rifle as opposed to a heavier barreled or competition type rifle. Would you be willing to expound on that? Is it just due to the lower expected consistency of a run-of-the-mill hunting rifle to where such a test could give misleading results?

Thanks again!
 

nealm66

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nealm66, thanks for hanging in here with me throughout with such a helpful and encouraging disposition! I'm going to look into the Caldwell rests and bags or something like it for load dev in the future.

I did just purchase an Eberlestock backpack mounted front rest which is on its way and I'm thinking with the backpack packed better that will be an improvement and something I can maybe use in the field too. I think the bipod may be getting retired for me at least for now.
I have done load work up on 5 or 6 vanguards and I usually don’t stop until they are inside a 1” square at 200 yards and it usually doesn’t take that long and not really necessary for a hunting rifle but that’s where all the ones I’ve worked on have ended up. I suspect yours isn’t any different
 

QuietTexan

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TL; DR - Shooting three shot groups is fine, Anna Nicole married for love, and other lies you tell yourself at night 👍 🤡

One question I have for you in from your main post in your illustration is that you advised not to do the 2 shot method early in load dev to eliminate the clearly least useful loads when loading for a hunting rifle as opposed to a heavier barreled or competition type rifle. Would you be willing to expound on that? Is it just due to the lower expected consistency of a run-of-the-mill hunting rifle to where such a test could give misleading results?
I used a barrel tuner as an example of when to use negative confirmation, the part about don't think you have to do that test on a hunting rifle is because shooting 10-shot strings chasing the absolute accuracy and precision offered by a barrel tuner might be (cough almost certainly is cough) an unnecessary waste of barrel life. Hunting rounds tend to be about power and speed, whereas competition rounds if there's no power factor then all that counts is precision. I don't want someone to think they need to burn 50 shots through a 26 Nosler trying to fine tune out the last quarter-inch of a group and end up with a shot out barrel for no real benefit. In competition good is never good enough, but when hunting the kill zone of a deer is pretty big relatively speaking, and doesn't get smaller if someone else shoots better than you. The 2-shot group/ barrel tuner example also assumes that you're at a point in load development where the majority of major issues have been addressed - seating depth, charge weight, and brass prep - and you're down to tuning barrel harmonics.

You can use 1-shot or 2-shot tests at many points in development, but only when seeking negative confirmation - that a load ISN'T something. You can say a 2-shot group probably isn't going to get better, but you can't say IS anything (pedantically, you can't even say for sure that it's worse than other groups), because the weakness of the data set precludes making any inferential conclusions. (I loved AP Stats way back when, sorry, I'm a nerd) which basically means that two shots might show "that could be good, or "it probably won't get better than how bad that was", but doesn't give you a real clue as to what the next shot will do.

And that's really what we're talking about - what will the next shot do. Trying to predict where the next bullet will land is the ultimate goal. An important part of that is how well you need to predict the next shot. In F-Class you need to know within 5" at 1,000 yards to hit the x-ring. Hunting, you have more leeway and need to know to within 10", and out to however far your cartridge makes good killing power/ the bullet will expand reliably/ whatever your preferred metric is.

The first two major steps in loading are usually seating depth and charge weight, in whichever order you prefer. For one I can accept negative confirmation, for the other I want to infer an conclusion.

When I shoot charge weight ladders, I usually initially do one load per step (I'll shoot 3-5 sometimes, but generally speaking here, average type stuff). Those shots on the ladder are really one-shot groups of each charge, which means I can't say for sure which charge is good in relation to a node, but I can find out pretty quickly where I'm not going to spend any more time. If my initial charge was off 100FPS out of 2500FPS for whatever reason (bad charge weight, chrono error) if by the end of the ladder I'm shooting 3100FPS I don't really care how badly it was off because it's so far removed from where I'll end up it's not relevant. I don't care about any predictive value from that charge weight going forward, I care that it shot safely and I didn't blow up my action by starting with too high a charge. One-shot groups worked great in that case by not wasting components and not rearranging my face, even if they aren't useful in predicting results going forward. I'll pick a "node" based on the logic that there's probably one in there somewhere, and it's probably somewhere around a flat spot on the chrono chart, but I don't expect the FPS readings to repeat very consistently until the load is fully dialed in - charge weight, seating depth, primer, etc. Charge weights should be resilient to at least 0.1gn, if not 0.2gn - absolute certainly that I'm square in the middle of a node after the first test isn't the goal of the coarse charge weight ladder. That comes later shooting groups around my speed and depth nodes.

Seating depth, I usually shoot five shots per depth, because in this case I am looking to make an inferential conclusion - I want try to know that there's a meaningful difference between the two groups. You can use two-shot groups here to determine if any seating depth probably isn't good enough (if the first two shots are three inches apart at 100-yards, maybe don't waste the next three shots), but with a decent barrel and components most likely more than one group will appear to be good enough (less than 1" at 100 yards, maybe even multiple groups clover-leafing). So you're down to splitting hairs, looking for sequential groups of good groups, and picking the one in the middle. When you do that you're apply the concept of confidence to your groups - if your 5-shot group is 1", there's a 90% chance every group at that setting will be between 0.25" and 3", aka "that could be good". If your group is 3", there's a 90% chance no group will ever be smaller than 1", aka "probably won't get better that how bad that was". If you shot 10-shot strings, you could change 90% to 95%. If you shot 20-shot strings you could change 95% to 98%. Maybe, statistics are funny, and a lot of variables can come in to play trying to shoot 20 shots in a row. So you pick the best group of 5 shots that's in the middle of two other decent groups because logically if the group you picked really isn't the best, at least the seating depth doesn't make the group fall apart as fast as if you picked the group that's right next to the 3" spread.

Unpopular opinion time: in reality 5-shot groups aren't enough to "prove" anything. 10-shot groups aren't enough. 20- and 50- groups still aren't enough. If the sample size is less than 100, we're still in the t-table space of "disproving the null" rather than proving anything conclusively. So, whether we mean to or not, we lean heavily on the concept of confidence intervals. Whenever anyone says "my 5-shot SD is 9 FPS", people who understand statistics hear "my 5-shot SD is 9 FPS, so there's a 95% chance the true SD of the 100-rounds I loaded last night is between 4-14 FPS." And guess what, a true SD of 14 FPS over 100 rounds is not bad. It's more than good enough for the majority of shooters at range outs to 1,000 yards, because that ammo will out shoot the shooter's other skills, or even the rifle itself. A 14 FPS SD won't win 1000 yard F-Class matches or King of 2 Mile, but when you're looking at the 16" kill zone on an elk at 600 yards shooting from the fetal position behind a log when it's snowing and 17* outside, that 14 FPS SD is going to get it done for you. That hand load is so much better than the 40 FPS SD of a questionably old box of Core-Lokts you found in the back of the closest before shooting two shots at a pie plate and going to whack Bambi's mom under the feeder at 85 yards like the majority of hunters in this country that it doesn't even bear comparing. Be proud of that true 14 FPS SD.

Rule of thumb:
  • About 22 data in each group is needed to detect a 1:2 ratio between two standard deviations
  • About 35 data in each group are required for a 2:3 ratio
  • About 50 in each group are required for a 3:4 ratio
Cite: https://precisionrifleblog.com/2020/12/05/muzzle-velocity-statistics-for-shooters/

So basically, to confirm anything, to really narrow down your confidence intervals, you have to shoot. A LOT. And that's exactly what competitors do. They overlay groups across matches and check SD/ES across loads, and hone in on exactly which brass prep steps matter and how to seat primers, and what jump is best for absolute precision and accuracy versus what jump is most resilient over 100 consecutive rounds. They're chasing 5FPS SDs on 30-shot strings, because that means there's a 95% chance the true SD of the population of every load they'll make is under 10FPS. Those shooters are awesome because they produce real, statistically meaningful results other people can rely on without having to shoot 100-shot strings testing every variable.

Hunters shooting 3-shot groups aren't proving that their loads are awesome. They're relying on statistics that generally speaking, a good bit of the time, in many cases, barring other things being wrong, and if they do everything right, then the load won't be the reason that they miss.

Pick your level of crazy and run with it. I'm a nutter, I'll admit that. But at the end of the day if the freezer is full, the rest is just noise right?
 
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dashender7

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You can use 1-shot or 2-shot tests at many points in development, but only when seeking negative confirmation - that a load ISN'T something.

Pick your level of crazy and run with it. I'm a nutter, I'll admit that. But at the end of the day if the freezer is full, the rest is just noise right?

Thank you again for the detailed writeup. I'm being educated. I actually appreciate the statistics rundown more than you might realize and I am glad you called my attention to the relevance of applying basic stats to reloading and accuracy and very large aggregate groups which equate to better sample sizes and higher statistical confidence.

My favorite takeaway from this is the concept of using small shot count or single round groups for negative confirmation, especially early in the load dev process to eliminate the most useless loads, as well as using one or two rounds to gather data about max pressure or flat velocity zones.

Also still appreciating the group overlay approach. I probably don't own a rifle that justifies being too much of a nutter but I do enjoy the load dev process.

I read recently an anecdotal story about famed American sniper in Vietnam Carlos Hathcock mentoring another shooter. It did not involve hand load development but I remember realizing he was on another level of nutty in his approach to gathering and analyzing first-shot data on a cold bore and first approach to the rifle in a given day and using his rifle workup to force himself to understand what to expect from that shot and make the first shot count. He would accumulate a huge body of data and sample of that particular condition; first shot in the day for rifle and shooter, and considered that to be the only body of data that mattered representatively for his field performance. Essentially he was overlaying 1 shot at a time into one huge group representative of what he could expect himself and his rifle to do cold while taking into consideration atmospherics. Seems that approach has some application for hunters too where single first shot should count. Of course Hathcock would have had much more to worry about in the event follow-up shots were needed than your average hunter, but still focused on this approach!
 
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