First round high flyer?

[tehweej]

So I was out verifying group size and velocity today out of my 10ba stealth. I had previously done some load work up and found a load that shoots about 1” at 100 yds. Today when I was shooting groups, I would have the first round hit 1.5” high, and then the rest into 0.5”. The chrono data did not give any reason as to why the first round was so high. My SD was single digits. My first suspicion was the action screws working loose a touch, but they were not loose. Next thought was the scope/ rings, but the rings were tight. It is possible the scope took a dive, I don’t have another one currently that I can swap; working on getting an LRTSi to put on it. I have a Leupold 1-4 because that’s all I have. I don’t think it’s my body positioning/mechanics, I am doing the same things I did for the 1” group.

Any other suggestions other than the scope going TU? I would think I wouldn’t be able to put the other four shots into the same hole if it was the scope.

 

[Thud]

What was the interval between groups time wise.
Did you shoot the first round from a clean cold barrel? And have a flier
And after shooting did the rifle settle down, or did it throw a shot high randomly.
3 or 5 shoot groups.

 

[tehweej]

5 shot groups. I would walk down to the targets between groups. So, 2 minutes max? Not really letting it cool down. It would do the same thing after each mag change. Didn’t clean between. I shot 5 groups and they all did this.

 

[Thud]

I think your barrel is cooling down. remember heat radiates out.
The carbon from the flame hardens slightly when cooled and the 1st shot will soften the carbon and will have a sight effect on speed. during your remainder string the barrel heats up to a uniform temp and the remainder shoots fall in line.
I benchrest we shoot a bunch of sighters to "heat the barrel up" so all record shoots fall into line. Some call it "fouling" the barrel.
If you know that the rifle will "throw" a shot when cold adjust your hold point to compensate for it.

To minimize the effect somewhat when cleaning pay attention to the throat area of the chamber that's where you can develop what called a carbon ring which also effects accuracy and will effect your chamber pressure and hence effect the accuracy chacteristics.
Some of the effects of a carbon ring are- loss of accuracy, blown primers, increased chamber pressure which left unchecked can lead to blown cases.
In this hobby there is a lot of cause and effect issues.
Check out Accurateshooter.com to help you understand the effects they have a wealth of knowledge there as here, They gravitate more to benchrest and long range accuracy.
Also if you change anything write it down and do 1 change at a time. If not you won't know what you did to solve a problem and if it doesn't work return to original setting.
If need more help just let me know.
Thud

 

[natdscott]

It could be you.

Make sure you aren't shouldering the rifle.

 

[tehweej]

Not saying it couldn’t be me! I know I am far from perfect! After seeing the trend I made a huge effort to shoot all shots the same. I very well could be “pushing” the first shot and setting in for the next 4. My groups are so damn similar I have a hard time believing it’s a flinch. I feel like I shot well, but feelings are subjective.

Carbon ring: this gun has around 100 rounds through it. Not seeing any pressure signs. I picked a load that is rather “gentle” by the standards I see on this forum. 147 ELDM @ 2643 by today’s data, so there would have to be some serious pressure increase as I have tested up to 2739 FPS without pressure signs. As far a speed change on the first shot, I saw anywhere from -10 to +20 FPS from the first to second shot.

 

[Thud]

A 30 fps speed change could be your problem.

 

[tehweej]

I’m absolutely going with the above — a tiny bit difference in load make a very large vertical difference in a system that has recoil.

Try barricade shooting load/support or free recoil. But if you mix them (with something that has a bit of recoil) you’ll most likely miss on a small target vertically.

I have never shot free recoil, its not something I have practiced. Typically, my setup is shooting from a Bulls Bag type rest in the front with a bunny ear or small squeeze bag in the rear. I pull the front rest back a bit so that I can push into the rifle. I usually shoot off the same bench, and if I push too hard the rest slips forward, so I try to push just enough to steady the gun. It has been good to me in the past, but something must be off.

Next time I go out I will try some different things with recoil management. And I will try to bring another shooter

Thanks for the advice!

 

[Greg Langelius *]

Cold gun/cold shooter? This has been discussed here many times. I suspect some shooter contribution, but also some gun contribution.

The first shot of a new string is always different to the shooter because they are not recovering from an immediately previous shot, and may not have settled into their position to the same degree that they do subsequent to immediately previous shots.

Illogically, a slower first round will usually impact higher. This because the bullet spends more bore transit time, subjecting the rifle/shooter system to more recoil duration, generating more muzzle rise and a correspondingly higher POI.

This is a commonly known occurrence among handgun shooters, who often need to 'regulate' the handload in order to accommodate fixed sights. The load's velocity is adjusted in order to raise or lower the POI; faster to obtain a lower POI, slower for a higher POI. Another approach would be to use lighter or heavier weight bullets.

For a distance of 100yd, a POI deviation of 1" vertically corresponds to 1/60th of one degree, which is a very small increment, as 30fps is a very small increment of the average velocity.

Greg

 

[tehweej]

The part about this that puzzles me is that I did things the same as when I did my load development initially, and shot this group:

~0.5" vertical spread with an ES of 33. Same load I shot yesterday.
Chrono data as follows:

2634
2637
2638
2625
2632

2624
2644
2642
2632
2646

2653
2646
2660
2638
2650

2656
2645
2653
2643
2651

2649
2656

​

The last group didn't get all the shots, but those are the first two.

Next time I shoot I will try free recoil to try to minimize my influence.

​

 

[Greg Langelius *]

I appreciate your commitment to getting the numbers and making the effort to exert the most control possible on the load development and group shooting process. I also did this for many years, but no longer even use a chrono.

I approach the process from the other end, concentrating my attention and effort onto the target and the target alone. I determine all my variables as arbitrary constants from the start, except charge weight. I do no prep to the brass beyond polishing and F/L resizing; whichever variables exist, I accept as a given. A chosen primer (CCI BR's), powder (Varget), seating depth (corresponding to AR magazine length limits), and I accept any other variables simply because the amount of additional work involved in attempting to control those variable amounts to more work and less effect than I consider ought to be worthwhile.

At most, I conclude that I'm trading off maybe a bit less that 1/4MOA's worth of accuracy. That last 1/4MOA is the expensive one, in terms of cash and time, both. As I age, I try to reserve my time more for shooting than for working at the loading bench, because time is my most limited resource these days. But seen from a longer vantage, time is really no less important a resource at my current age than it was a half century ago.

Charge weight is the sole/key variable, and I use the Hornady Lock-n-Load automatic powder measure to precisely weigh each charge. I also make a lot of test loads, maybe 25 of each increment, maybe more. Shooting 5 round groups, I find that the main variable in group sizes between increments is the shooter myself. Typically, it is the last two groups within the increment which reveal the most consistent sizes.

To me, the target is the goal, and the target is the true indicator of an effective charge weight. Yes, evaluating other factors will develop more accuracy, but for my purposes, what I get is plenty accurate enough for my own limited needs. At 71, I no longer feel a driving need to achieve the ultimate in accuracy. If I can do better than 3/4MOA, I'm fine; and if I'm getting 1/2MOA (and I occasionally do), all is most excellent.

Understand, that I am also working with factory rifles. At this stage of my life, my ultimate goal is simplicity. Also, at this stage in my life, I'm really only looking to meet with my own goals, and not those of others. I'm seeking personal bests.

What I'm trying to suggest here is that we can overwork a problem, and that somewhere in all of this we may be losing sight of the simple fact that what we do is supposed to be fun, first of all. If I'm cussin' and fussin' I stop and remind myself of the real goal.

Greg

 

[tehweej]

There is a lot of wisdom in that post Greg! I find myself agreeing with what you said to a large degree. I used to not have a chrono, and a buddy has lent me his 35p. I also do very limited brass prep, and this is the first rifle I have splurged and bought Lapua brass for. I would LOVE a 1/4 moa gun, but that requires more money than I care to spend. I read the “How much does ____ matter?” on the prs blog, and decided 1 moa is good, 1/2 would be stellar, and I need to learn to shoot wind. I would love to have this thing shoot under 1 moa, that is my goal, but seeing it shoot so damn well with a flyer (that was previously not present) is frustrating. Reloading for me is almost as enjoyable as the actual trigger pulling, but it can also be a source of frustration. If it so happens that this rifle shoots the first shot 0.5 mils high (I found my target and measured, 1.8”@100 yds), then it does. Maybe I just need to learn to shoot ?

 

[Alan101]

If you are using a solid rifle and solid ammunition and having anomalies, look at yourself as the shooter first. As much as I hate to admit it, I have wasted significant time an energy chasing phantom problems when ended up being a problem with the idiot behind the trigger, me.

 

[Greg Langelius *]

My approach would be to recognize that all I'm shooting is paper (nearly all the time), and that I can afford to shoot a few foulers before I settle in on banging out the groups. I set aside a few extra rounds for use as foulers when I'm doing load development.

All my shooting these days is recreational. I had tried for a "Grand Senior" swan song last February at the Berger SW LR Nationals in the 600yd MR matches. Everything was up to speed but my ticker, and I ended up withdrawing after finishing the first of 3 matches. I learned something, and still had myself a heart attack two months later. I'm slowly working my physical condition back up to where it needs to be (we now own a treadmill, and I'm doing pushups, sit-ups, and some modified pull-ups), and may give it another try next year (or not, it's only worth doing if it's still fun....).

I no longer put much faith into the cold, clean bore idea. The rifle shoots more consistently, especially when cold, when its not coming off a serious cleaning.

However, when I'm doing load development, if the bullet jackets change, a cleaning and up to ten rounds of fouling will square way any 'oddness' associated with changing from one brand of bullets to the next. It's worth doing.

IMHO, the point of the load development testing is to get reliable data, and the most certain way I can think of to do that is to increase the size of the sample. Five sets of 5rd groups is more reliable than two, or one of them. Besides, I'm there to be shooting, so I may as well do more of it.

By all means do not relax standards for the sake of simplicity; I just want to put my own emphasis these days on the shooting, rather than the handloading. This represents a big change in me over the past decade and some, since my first heart attack, my 2004 Christmas present. My life these days is about finding simplicity, and cutting down on the self induced stress. Taking a step aside and removing my own self from the equation, I think there's a lesson to be learned from doing that, no matter what one's age may be.

The question about how much X or Y means in the overall scheme is good, but I've learned there's more to it than just the X or the Y in and of themselves. They all work together to form the whole; some adding, and some detracting. Rather than playing "whack a Mole" sorting out each from the other, I asked myself just what i wanted to end up with in the long run. Like, how much enjoyment was I getting out of polishing the apple more and more? My answer today is quite different from what it would have been before 2004. I see handloading as a necessary evil which allows me to enjoy more shooting for my shooting dollar. Obviously, doing it in a haphazard manner wastes more than it saves, but one can still draw some very dark lines that marginalize much of the soothsaying and arcane incantations. The simplest answer which still dots the I's and crosses the t's is the one that cleaves most true to the straight line.

So I decided I really didn't need to test four brands of primers with each bullet/gun combination, or have a full dugout in the powder department. I do shoot F T/R with a Bob Sled, but my rounds will still feed from the AR mag the rest of the time. My 223 loads are intended to shoot in both 1:9" and 1:8" twists (hence the shorter HDY 75gr HPBT-Match), and some effort is made to find a happy compromise load that works well in a fair number of my guns.

More perfection than this is simply not required. YMMV!

Greg