Horizontal Groups

[mikehill85]

I am reloading for a Bergara B14 HMR in 308. I am using Lapua Brass, 175 Grain Sierra Matchking BTHP bullets, and IMR 3031 powder (I prefer 4064 but this is what I was able to get my hands on recently). I am shooting off of a Caldwell Rock BR front rest with a Protektor rear bag. Last week I went to the range and I got the below groups, shooting at 100 yards (Please ignore the upper left group...I was shooting off of a bipod there...without a proper bag for the task...the results were horrible so I went with my rest for the other 3).

Anyway, I am obviously getting a lot of horizontal stringing and there wasn't a ton of wind the day I was shooting. I am wondering if anyone has any thoughts on how to reduce the horizontal.

My thoughts are:

1. I was shooting off of wooden benches and noticed that my rear bag moved with recoil (due to the poor grip on the wood) and I had to reset it. I plan to design and 3d print a base for the bag to sit in. I will attach cleat spikes to the bottom and this should stop the bag from moving.
2. I might try tweaking the seating depth a bit (though this was the start of a 15 thousandths node where the load I am shooting produced the smallest groups with this powder charge, so I have played with tuning seating depth. The seating depth (with the same powder charge) about 10 thousandths back (i.e. seated 10 thousandths deeper) produced a smaller more round group but it was basically a split group with 3 rounds touching and 2 above. 5 thousandths back from my current seating depth, I shot a group that actually had 4 touching and one low and right that ruined the group (I may have screwed up here ...4 of the shots were 0.36" C-T-C...The shot that was out of the group blew it up to 1.29"...So it's possible I may have canted the rifle on the shot that was way out of the group...).

Any thoughts/suggestions are welcome.

 

[spife7980]

Could be a million things. Test to figure it out. Its probably you.

 

[nn8734]

Could be shooter…are you watching the cross hair for movement as you’re squeezing the trigger? I get horizontal stringing when im gripping the grip too hard.

 

[enichols]

That kind of horizontal stringing happens to me when I don't properly execute the fundamentals of natural point of aim/body position, grip, and/or trigger finger placement on the trigger.

But your bottom left group looks like a smiley face, so at least there's that.

 

[Doom]

That kind of horizontal stringing happens to me when I don't properly execute the fundamentals of natural point of aim/body position, grip, and/or trigger finger placement on the trigger.

But your bottom left group looks like a smiley face, so at least there's that.

I think that the above is where the issue resides. If
I don’t pay attention to my grip ( thumb placement ) and trigger follow through I’ll get this.

 

[Sogan]

Horizontal can also be seating depth issues, no? But I do agree that if the gun is slipping around then I would try and fix all those issues before going to seating depth.

 

[ArTeeKay]

You likely already know all of the following, but since you asked, and didn't mention much at all about your technique, these are the things that come to mind.

Shooting off bags and rests can encourage bad technique if the rifle isn't tracking well in the bags. You'll be muscling the rifle into the target, which will wreck your horizontal. Once you get on target, close your eyes, take a deep breath and let the rifle settle again, then open your eyes. If the reticle has moved from your point of aim, you need to fix the way you're interfacing with the rifle.

Secondarily, I'm not sure what your scope reticle looks like, but your target and groups sort of suggest you're not really locking into a consistent point of aim. If you have a target with more finite aiming point, one that encourages consistent POA, I suspect you'll see quick improvement when shooting for groups.

Last, fliers, unless called and called correctly, aren't fliers, they're legitimate data points. If you aren't certain that canting your rifle caused your .36" group to open up to 1.3", then don't discount the data point, and try to figure out what it's telling you. If you believe canting your rifle did in fact blow your group, but you weren't aware of it til after the fact, then how can you be sure that it's not the cause of your unsatisfactory groups generally?

 

[smoothy8500]

...the results were horrible... The bag moved....I may have screwed up here ...I may have canted the rifle....

I think for now the load is fine and you should concentrate on technique. The Online Training is really good and a reasonably priced value. Here you basically admit that something is wrong but cannot say what. Online training, dryfire practice, focusing on NPA, hold, trigger pull, hand placement, etc, will dramatically help you.

 

[Pharmseller]

Horizontal can also be seating depth issues, no? But I do agree that if the gun is slipping around then I would try and fix all those issues before going to seating depth.

In my experience seating depth issues manifest as triangular groups.

Horizontal, if not the wind, is usually technique.

 

[Taylorbok]

If you think you had good fundamentals Try adding 0.3gr of powder to the load and see what happens. could maybe tune it with seating depth but a touch more powder is easier to test first

 

[mikehill85]

If you think you had good fundamentals Try adding 0.3gr of powder to the load and see what happens. could maybe tune it with seating depth but a touch more powder is easier to test first

I think my fundamentals are good and I made sure to focus on them when shooting those 3 groups. That said, I have switched from a range with concrete benches which I shot at for years to a new range closer to my house with wooden benches and my rear bag was definitely moving backwards a bit. That could definitely be the cause of the problem or at least contribute to it.

The thing is, I shot the exact same load as those 3 groups about a month ago, different day, different wind and I got a similarly horizontal group and it's really only this load that I have gotten these bizarre horizontal groups with, which is why I think it might very well be the load.

I think this is good advice. I actually saw an interview with Jack Neary on Erik Cortina's Youtube channel where he was saying that often these horizontal groups can be fixed with a bit more powder.

I think I will: 1. Focus on fundamentals/proper technique (Which is something I always try to do but its importance can't be understated...and the advice of everyone else here saying that it could be me is well taken...I will always admit that I'm not perfect and it could always be me...)., 2. Sort out the poor grip my rear bag has on the wooden benches. 3. Try adding a bit more powder if 1. and 2. don't sort it out.

 

[Taylorbok]

I think this is good advice. I actually saw an interview with Jack Neary on Erik Cortina's Youtube channel where he was saying that often these horizontal groups can be fixed with a bit more powder.

That's where I got the info, Cortina has put out some really great videos. I'm a subscriber over on his forum. That info helped me really tighten up buddies 28 nosler the other day.
here is the link if anyone else cares to watch.

 

[mikehill85]

That kind of horizontal stringing happens to me when I don't properly execute the fundamentals of natural point of aim/body position, grip, and/or trigger finger placement on the trigger.

But your bottom left group looks like a smiley face, so at least there's that.

Yes. It is cool that it looks like a smiley face...not what I was going for but some consolation, I guess. Lol.

 

[BuildingConceptsllc]

I think my fundamentals are good and I made sure to focus on them when shooting those 3 groups. That said, I have switched from a range with concrete benches which I shot at for years to a new range closer to my house with wooden benches and my rear bag was definitely moving backwards a bit. That could definitely be the cause of the problem or at least contribute to it.

The thing is, I shot the exact same load as those 3 groups about a month ago, different day, different wind and I got a similarly horizontal group and it's really only this load that I have gotten these bizarre horizontal groups with, which is why I think it might very well be the load.

I think this is good advice. I actually saw an interview with Jack Neary on Erik Cortina's Youtube channel where he was saying that often these horizontal groups can be fixed with a bit more powder.

I think I will: 1. Focus on fundamentals/proper technique (Which is something I always try to do but its importance can't be understated...and the advice of everyone else here saying that it could be me is well taken...I will always admit that I'm not perfect and it could always be me...)., 2. Sort out the poor grip my rear bag has on the wooden benches. 3. Try adding a bit more powder if 1. and 2. don't sort it out.

Why is your rear bag moving?

 

[mikehill85]

Why is your rear bag moving?

It is moving back a bit with each shot. I assume it is because the coefficient of friction between the wood and the bag isn't as high enough to prevent it from sliding. It is a Protektor ‎#13B which is a 6 lb+ bag...I figure if I add some anti-slip tape to the bottom of the bag and/or add a dryer sheet in between the stock and the bag it should stop the bag from sliding. I have removed all sling studs from the stock, etc., so the stock isn't catching on the bag. <- To be clear, there were no sling studs installed when I shot the 3 groups I posted here.

 

[n2ishun]

Horizontal stringing is ~usually~ you either pushing on the grip or butt, or you pulling on the trigger.

Get the rifle hunkered down and perfectly centered on target, barely breathe on the butt and trigger.....and oh yea, don't breathe

 

[fdkay]

Horizontal stringing is ~usually~ you either pushing on the grip or butt, or you pulling on the trigger.

Get the rifle hunkered down and perfectly centered on target, barely breathe on the butt and trigger.....and oh yea, don't breathe

Concur, likely booger hook

 

[Baron23]

With me, this sort of group usually goes to trigger control….something that I’m always working on and certainly have not perfected.

I will also say, however, that I’ve never understood why people only look to MV and barrel harmonics for vertical stringing as I’m not aware of any reason why vibrations in a round barrel would only Sun to a vertical vector. I see no reason why it can’t also express itself horizontally and would love to engage a PhD physicist and maybe a mechanical eng on this.

 

[nn8734]

With me, this sort of group usually goes to trigger control….something that I’m always working on and certainly have not perfected.

I will also say, however, that I’ve never understood why people only look to MV and barrel harmonics for vertical stringing as I’m not aware of any reason why vibrations in a round barrel would only Sun to a vertical vector. I see no reason why it can’t also express itself horizontally and would love to engage a PhD physicist and maybe a mechanical eng on this.

Stringing isn’t usually a byproduct of a less than favorable load as those typically show as either a larger than desired triangle pattern if three shot group or just a large but otherwise mostly disbursed group in the X and Y axis.

Strings of impacts in either plane is usually shooter. Not 100% of the time but id look at shooter fundamentals before blaming the load recipe.

 

[Baron23]

Stringing isn’t usually a byproduct of a less than favorable load as those typically show as either a larger than desired triangle pattern if three shot group or just a large but otherwise mostly disbursed group in the X and Y axis.

Strings of impacts in either plane is usually shooter. Not 100% of the time but id look at shooter fundamentals before blaming the load recipe.

Yeah, I don’t disagree but then you have endless threads on positive compensation and finding an MV that will result in the bullet exiting the muzzle at one of the end points of the oscillation where movement would be small to nonexistent.
And that never made much sense to me.

 

[nn8734]

Yeah, I don’t disagree but then you have endless threads on positive compensation and finding an MV that will result in the bullet exiting the muzzle at one of the end points of the oscillation where movement would be small to nonexistent.
And that never made much sense to me.

Lol, that one was a doozy. Yea I think that applies more at distance usually near or beyond transonic and works by varying the launch angle such that the higher velocity shots launch shallower than the lower velocity ones so they end up at the same place on the target after travelling in their respective ballistic trajectories but who knows.

I get vertical stringing at 100m when im sympathetically squeezing my rear bag and horizontal when breathing is “off” ie varying NPA or when i death grip the grip and the extra tension results in poor trigger manipulation/ control.

 

[ZY100]

Look at the where the elbow of your trigger hand is resting on the bench when you shoot. Is it forward of your cheek? Try it with your elbow back behind your cheek/shoulder.

A lot of times we set up funky on a bench and don’t realize it.

ZY

 

[mikehill85]

With me, this sort of group usually goes to trigger control….something that I’m always working on and certainly have not perfected.

I will also say, however, that I’ve never understood why people only look to MV and barrel harmonics for vertical stringing as I’m not aware of any reason why vibrations in a round barrel would only Sun to a vertical vector. I see no reason why it can’t also express itself horizontally and would love to engage a PhD physicist and maybe a mechanical eng on this.

I guess you’re in luck then because I am actually a mechanical engineer. I’d say the main reason most barrel whip happens in the vertical plane is that most barrels are off-center with respect to where they are being held in the action and the external force slowing the rifle itself down (e.g. the shooters shoulder or friction on the bottom of the gun if you are shooting free recoil. This causes muzzle rise and creates some barrel flex mostly in the vertical plane. But you can definitely have situations where you get horizontal dispersion (e.g. the barrel isn't centered with respect to the action screw holes or uneven force of friction slowing down the gun on each side). In reality you will get barrel whip in both planes because nothing is machined 100% perfectly but it should generally be much more pronounced in the vertical. If you were shooting your rifle sideways (i.e. rotated 90 degrees like a gangsta), I supposed you'd get more horizontal dispersion than vertical though.

 

[Baron23]

I guess you’re in luck then because I am actually a mechanical engineer. I’d say the main reason most barrel whip happens in the vertical plane is that most barrels are off-center with respect to where they are being held in the action and the external force slowing the rifle itself down (e.g. the shooters shoulder or friction on the bottom of the gun if you are shooting free recoil. This causes muzzle rise and creates some barrel flex mostly in the vertical plane. But you can definitely have situations where you get horizontal dispersion (e.g. the barrel isn't centered with respect to the action screw holes or uneven force of friction slowing down the gun on each side). In reality you will get barrel whip in both planes because nothing is machined 100% perfectly but it should generally be much more pronounced in the vertical. If you were shooting your rifle sideways (i.e. rotated 90 degrees like a gangsta), I supposed you'd get more horizontal dispersion than vertical though.

Thank you…and yes, sadly I’m the kind of jerk who asks for expert help then argue with them when it’s given

So, what you described seems to me to be muzzle jump from recoil not being fully directly in line vertically with where the butt is supported resulting in off center rearward movement w a vertical component (yeah, I’m prob not describing this well).

But I think (thought) that there is another effect in play and that’s barrel harmonics and the small oscillating movement is the basis for positive compensation (and I may have this all fucked up).

To my mind ( what little is left), lighting off a cartridge in the chamber is much like hitting one end of the barrel w a hammer causing primary vibration and it’s harmonics (again, prob not describing this well) that propagate down the length of the barrel and sum into some macro movement for which I see no reason for it to be limited to the vertical plane.

I think if you mounted the barreled action to a block of concrete and lit one off, you would still have vibration propagating down its length resulting in some oscillation but why would that be only a vertical movement.

And yes, I’m old, retired, and somewhat bored so I do occupy myself with this sort of stuff. You should have seen my shit show of a thread questioning the physics of why shooting up hill will result in a higher impact (less drop) than expected for that slant range.

Cheers and thanks again.

 

[straightshooter1]

I guess you’re in luck then because I am actually a mechanical engineer. I’d say the main reason most barrel whip happens in the vertical plane is that most barrels are off-center with respect to where they are being held in the action and the external force slowing the rifle itself down (e.g. the shooters shoulder or friction on the bottom of the gun if you are shooting free recoil. This causes muzzle rise and creates some barrel flex mostly in the vertical plane. But you can definitely have situations where you get horizontal dispersion (e.g. the barrel isn't centered with respect to the action screw holes or uneven force of friction slowing down the gun on each side). In reality you will get barrel whip in both planes because nothing is machined 100% perfectly but it should generally be much more pronounced in the vertical. If you were shooting your rifle sideways (i.e. rotated 90 degrees like a gangsta), I supposed you'd get more horizontal dispersion than vertical though.

Hmmm??? As a mechanical engineer, how would you differentiate (or describe the difference) between "barrel whip" and "barrel harmonics"?

 

[Evintos]

That's where I got the info, Cortina has put out some really great videos. I'm a subscriber over on his forum. That info helped me really tighten up buddies 28 nosler the other day.
here is the link if anyone else cares to watch.

I feel like this Jack Neary vid should also be watched in conjunction with the interview vid since it also has a visual aid.

 

[Barelstroker]

I feel like this Jack Neary vid should also be watched in conjunction with the interview vid since it also has a visual aid.

Jack had some very interesting things to say in the interview with Eric which I thought were very insightful then, I watched one of Jacks videos of his classes regarding "reading the shape of the group" &, to be brutally honest, I can't think of where I've heard that much contradiction & baseless assumption in one video in all my life.
Turned me off the guy completely.

 

[mikehill85]

Thank you…and yes, sadly I’m the kind of jerk who asks for expert help then argue with them when it’s given

So, what you described seems to me to be muzzle jump from recoil not being fully directly in line vertically with where the butt is supported resulting in off center rearward movement w a vertical component (yeah, I’m prob not describing this well).

But I think (thought) that there is another effect in play and that’s barrel harmonics and the small oscillating movement is the basis for positive compensation (and I may have this all fucked up).

To my mind ( what little is left), lighting off a cartridge in the chamber is much like hitting one end of the barrel w a hammer causing primary vibration and it’s harmonics (again, prob not describing this well) that propagate down the length of the barrel and sum into some macro movement for which I see no reason for it to be limited to the vertical plane.

I think if you mounted the barreled action to a block of concrete and lit one off, you would still have vibration propagating down its length resulting in some oscillation but why would that be only a vertical movement.

And yes, I’m old, retired, and somewhat bored so I do occupy myself with this sort of stuff. You should have seen my shit show of a thread questioning the physics of why shooting up hill will result in a higher impact (less drop) than expected for that slant range.

Cheers and thanks again.

I would say if you took a barrel and put a concrete block on the end in set it off on space (with no friction on the block) it would just accelerate the gun and block straight backwards. The block would also rotate because the barrel is rifled but we don't really care about that here. You would get vibrations in the barrel but they would be straight along the length of the barrel and would be caused by the barrel trying to accelerate through the block but being stopped by it/ some annular stretching of the barrel from firing.

If you took that same setup and put it on the ground and fired it, the gun as a force accelerating it backwards but you also have the force of friction pushing on the bottom of the block slowing the gun down (and stopping it from flipping over presumably), creating torque between the barrel and the bottom of the block. This torque between the barrel and the bottom of the block makes the barrel flex (changing the angle between the barrel and the ground). Because the metal in the barrel is elastic it will oscillate up and down. This actually happens for the entirety of the bullet's trip down the barrel and it's made even more complicated because the pressure in the barrel changes as the bullet moves down the barrel. This means you get a varying force accelerating the gun backwards...making your oscillations even more complicated.

So the barrel is going to oscillate (mostly up and down) but it's not going to be a nice pretty sine wave (as is used in illustrations because it is easier to think about). It's going to be really complicated and dependent on things like the metal the barrel is made of, the powder burn rate, the bullet weight, the coefficient of friction between the block and whatever surface it is placed on, etc.,...which is why we experiment, instead of calculating.

One other thing that will no doubt contribute to vertical harmonics is the fact that the barrel and bottom of the stock probably are never perfectly parallel. That means there will be a vertical velocity component between the stock and the barrel which will add more to the torque between the barrel and the stock and the up and down motion of the barrel.

Anyway, all of this is part of the reason that bench rest shooters try to get their guns to slide backwards with as little friction as possible, without actually touching the back of the stock (the gun won't recoil very far before the bullet has left the barrel...so even a little space for "free recoil" will do). Less friction will generally result in less torque between the barrel and the stock and a smaller amplitude in the vertical dispersion. If there is little friction between whatever the gun is resting on and the bottom of the stock, the amplitude will be low and the effect of the vertical dispersion will be lessened.

Not sure if that made any sense. Lol.

Don't feel bad about arguing with people about things...Some of us are such jerks we get a degree in it so we can do it for a living...At least you're not that bad...

 

[mikehill85]

Hmmm??? As a mechanical engineer, how would you differentiate (or describe the difference) between "barrel whip" and "barrel harmonics"?

I guess I would say barrel whip is more or less the distance the end of the barrel moves with respect to its rest position. Barrel harmonics result in barrel whip and how it changes with respect to time and other variables (barrel temperature, etc.,).

 

[straightshooter1]

I guess I would say barrel whip is more or less the distance the end of the barrel moves with respect to its rest position. Barrel harmonics result in barrel whip and how it changes with respect to time and other variables (barrel temperature, etc.,).

Thanks for your response.

Hmmm??? Describing Barrel Whip that way doesn't seem to cover the full distance that a barrel travels from its rest position. That the distance is something like 2x from the rest position as it moves in one direction (like to a high vertical position) then back past the rest position to a point beyond the rest position for a total movement in one cycle then less movement around the rest position in the next cycle. Sorry for being anal about his. It's just that words are important for drawing a picture that helps all of us better understand what's gong on.

When we talk about Barrel Whip, it typically referrers to the oscillations, which are usually quite large and visible (especially in slow motion) after the projectile has left the muzzle.

Barrel Harmonics typically referred to the barrel vibration initiated by the spiking pressure pulse at the initial ignition of the powder which sends a vibration pulse through the metal barrel at the speed of sound for steel . . . way faster than the movement of the projectile through the barrel. That vibration is very small and is as a sine wave, which continues until the vibration decays away (well after the projectile has left the muzzle). It's these harmonic oscillations that we're trying to time the projectiles barrel time to match the anti-node of this sine wave (I know, it's not a perfect sine wave given what you've mentioned, like the effects of the projectile moving down the barrel).

I'm just trying to be clear, so there is less confusion when someone mentions Barrel Whip vs Barrel Harmonics that we so often see mentioned in these various threads.

If you can better clarify . . . I'm all ears!

 

[mikehill85]

Thanks for your response.

Hmmm??? Describing Barrel Whip that way doesn't seem to cover the full distance that a barrel travels from its rest position. That the distance is something like 2x from the rest position as it moves in one direction (like to a high vertical position) then back past the rest position to a point beyond the rest position for a total movement in one cycle then less movement around the rest position in the next cycle. Sorry for being anal about his. It's just that words are important for drawing a picture that helps all of us better understand what's gong on.

When we talk about Barrel Whip, it typically referrers to the oscillations, which are usually quite large and visible (especially in slow motion) after the projectile has left the muzzle.

Barrel Harmonics typically referred to the barrel vibration initiated by the spiking pressure pulse at the initial ignition of the powder which sends a vibration pulse through the metal barrel at the speed of sound for steel . . . way faster than the movement of the projectile through the barrel. That vibration is very small and is as a sine wave, which continues until the vibration decays away (well after the projectile has left the muzzle). It's these harmonic oscillations that we're trying to time the projectiles barrel time to match the anti-node of this sine wave (I know, it's not a perfect sine wave given what you've mentioned, like the effects of the projectile moving down the barrel).

I'm just trying to be clear, so there is less confusion when someone mentions Barrel Whip vs Barrel Harmonics that we so often see mentioned in these various threads.

If you can better clarify . . . I'm all ears!

Sure. I can clarify. Neither is a scientific/technical term and that's how I use them. No doubt the fact there is no technical definition and everyone has their own is what is leading to the confusion you mentioned.

P.S.
That said, I do think I like your definition of barrel whip better because it does seem that most people are talking about the maximum distance the barrel displaces which actually happens to its greatest extent after the bullet has left the barrel, as you pointed out.

In my definition of barrel harmonics, we are describing the displacement of the barrel both before and after the bullet leaves...I know that's not of interest to reloaders but there's no reason it should be limited to when the bullet is traveling down the barrel only, if that makes any sense. I think we are talking about the same thing but describing it in a different way/perhaps different parts of it.

I would add that I don't think the initial pulse from firing alone is what causes all the harmonics in the barrel. If that were the case, I don't see why most of the displacement would be in the vertical plane. I think part of it is from the barrel actually stretching and an "annular wave" going down the length of the barrel and coming back. Part of it is from what I previously describe...that part being the main cause of the vertical displacement. It's a complicated process to be sure.

Looking into it a bit, it seems there are several theories out there. One that is like you described and one like I described. I will never claim to be infallible and if there's good reason to use one theory over the other or even combine them, I definitely open to that. We learn the most when we discover something we didn't expect/didn't account for in our theories/ideas.

 

[Baron23]

You briefly described those pretty well.
Here is a short article describing some more of it. I won’t try restating any of it lest I confuse the issue more.

Rifle Accuracy: Barrel Harmonics Effects on Rifle Accuracy Explained

Thank you...that goes far more to what I was trying to ask about than muzzle jump from recoil and offset from line of force and longitudinal axis of the stock/chassis....or something like that! haha ;-)

 

[Boomdog]

Sorry to intrupt your thread, but can anyone help reading this group. I also sent it to my girlfried to get her take on it. New 6 CM with 108 ELDMs.

 

[mikehill85]

Sorry to intrupt your thread, but can anyone help reading this group. I also sent it to my girlfried to get her take on it. New 6 CM with 108 ELDMs.

Nothing wrong with it but I think sending it to your gf was a mistake. It's obviously way bigger than what she's used to seeing. You don't what to let her know there's something like that out there. *jokes*

 

[mikehill85]

Thank you...that goes far more to what I was trying to ask about than muzzle jump from recoil and offset from line of force and longitudinal axis of the stock/chassis....or something like that! haha ;-)

To muddy the waters further...Here are multiple competing theories to confuse you and make you wish you'd never asked me a question. J/K.

RSI - General Reloading Tips

Barrel Harmonics, Timing & Theory

www.shootingsoftware.com

 

[Baron23]

confuse you and make you wish you'd never asked me a question. J/K.

hahaha...that's the story of my life.

 

[mikehill85]

Update:

I thought my fundamentals were good but it looks like the people who thought my trigger pull was off were right. I shot these two groups this past weekend when I really focused on my trigger pull.

The upper one really hurts. LOL. Both are 5-shot groups at 100 yards. Anyway, the rifle can clearly outshoot me with this load so I'm going to make some more cartridges and focus on becoming a better shooter. Before anyone asks, I adjusted the scope in between the groups which is the reason for the point of impact shift.

Thanks to everyone for their input.