Advanced Marksmanship Slight POI shift between groups or dot drills

[TheGerman]

I'm splitting hairs at this point but was wondering if this had to either do with finite rear bag manipulation or with my head/face being every so slightly at a different distance from the optic.

So for example:

Scope sighted at 100, nothing loose, parallax adjusted. Shooting groups at 1 inch dots, same scope, same ammo, same everything. Load 5 and shoot a .6 group ontop of each other in the middle of the 1 inch target paster. Load 5 more, adjust nothing, change nothing and shoot a .5-.6 5 shot group, but now that group is 1/4-1/2 an inch to the left side of the paster. Load 5 more, adjust nothing, change nothing and shoot another .5-.6 group in the middle of the next 1 inch paster.

Same with dot drills. 8 in a row in the middle, next 2 are the same distance OUTSIDE the dot to the left of it. Then back to hitting dots.

What's causing the shifts, which are not erratic, but seem to show up when I am doing whatever to cause them. Face/head position slightly moving after some recoil? Rear bag getting compressed/formed under recoil?

 

[j-huskey]

Please describe front rest (bag, bipod, hand, etc), shooting position surface (ground, concrete, table, etc), and "your shooting position" (prone, sit, etc) ?

What's happening on the front end might be important as well as those bag, face, etc, actions you describe.

A recent poster aar"ing one of Frank's classes was doing something similar and Frank caught him squeezing his thumb on the stock as he squeezed the trigger, causing it.

My department trainees generally do it torquing the bipod just enough to change npa when shooting dot drills, and reposition the rifle just enough to regain npa when they realize it. But. Without knowing your front rest and surface, this is only surmise.

 

[TheGerman]

Desert ground and a bipod up front. I know from experience in Afghanistan that the bipod digging in over time will make the front 'bounce' slightly under recoil sometimes sending the barrel upwards, but this isn't that. But yes, I have to move the gun every now and again because the bipod does work itself into the packed sand/rock soil we have here.

Under the rear is just a TAB rear bag, shooting prone on the deck in the desert.

It's something small I'm doing like my head moves slightly under recoil or the rear bag is settling, or the bipod is digging or something. It's splitting hairs, but its obnoxious and I didn't want to spend a bunch of rounds trying to change/focus on specific things and chase my tail. When it happens it happens uniformly, in that, it will shoot a small group or be extremely repeatable, not like I'm throwing rounds or getting flyers, etc.

 

[j-huskey]

Rgr, only thing I might try is video you shooting and go back and try to find it on the video,

Or if you have a really sharp bud watch you.

 

[TheGerman]

Rgr, only thing I might try is video you shooting and go back and try to find it on the video,

Or if you have a really sharp bud watch you.

Yeah you're the 2nd person today to tell me that lol

Might as well try it. I did video myself running a pistol 'course' after running a mile beforehand the other day just to see what it actually looked like lol

ETA - A problem I used to have with a semi was shooting over the target at distance because of the rear bag 'giving out' to the recoil thus allowing the barrel to angle up. I keep going back to the rear bag somehow with this. Assuming parallax is gone, I can't see how my face position would change the POI much as isn't taking the parallax out of the equation basically negating that?

 

[j-huskey]

Unless your face movement is giving you the tiniest of scope shadow that you are missing seeing....
Just a thought. But, I've caught myself doing the shadow effect shooting a thermal when wearing a helmet and the edge of the rhino hits the eyepiece and I move head just enough to blow the shot. Doesn't happen when I dump the helmet, and I dont have the option of moving the scope because the eye relief is a bit short for shooting nv helmet. Jmhe

 

[Deleted member 10043]

Why are you wearing a fucking helmet in Alabama?

 

[Deleted member 10043]

Or is it Arkansas?

 

[j-huskey]

Or is it Arkansas?

U mean your wife doesnt try to hit you with a bat about your head ?
It's like this, wife hunts me with bat. I hunt her with taser, and helmet with night vision .
It's a much tougher version of rodeo sex. She likes pretend necrophilia so she tries to knock me unconscious.
I like it when shes flopping from the tazer.

You should try it. Spice up your relations with your sister, just sayin, Arkansas hill style.... ????????

1J told me SirHRMechanic has to use a helmet when he tries goat oral because they kick too much. I haven't tried that yet. ??? not going to either....

 

[Subwrx300]

U mean your wife doesnt try to hit you with a bat about your head ?
It's like this, wife hunts me with bat. I hunt her with taser, and helmet with night vision .
It's a much tougher version of rodeo sex. She likes pretend necrophilia so she tries to knock me unconscious.
I like it when shes flopping from the tazer.

You should try it. Spice up your relations with your sister, just sayin, Arkansas hill style.... ????????

1J told me SirHRMechanic has to use a helmet when he tries goat oral because they kick too much. I haven't tried that yet. ??? not going to either....

????

 

[diverdon]

Same shit happens to me. In my head I designed a cheekpiece and a buttpad with pressure sensors to help me have perfectly consistent pressure. While it seems like a great idea, I'm to lazy to build it.

 

[TheGerman]

Unless your face movement is giving you the tiniest of scope shadow that you are missing seeing....
Just a thought. But, I've caught myself doing the shadow effect shooting a thermal when wearing a helmet and the edge of the rhino hits the eyepiece and I move head just enough to blow the shot. Doesn't happen when I dump the helmet, and I dont have the option of moving the scope because the eye relief is a bit short for shooting nv helmet. Jmhe

Someone needs an ANVIS 9

 

[TheGerman]

Same shit happens to me. In my head I designed a cheekpiece and a buttpad with pressure sensors to help me have perfectly consistent pressure. While it seems like a great idea, I'm to lazy to build it.

Yeah I've designed this thing in my head that somehow is a magnet on your shoulder (like a limb saver) that can be activated and works with the magnet you put in the stock of the gun and holds it to the point NOTHING will move it once activated.

 

[j-huskey]

Someone needs an ANVIS 9

Well, Christmas IS coming.... ? I'm ok with a used in afg by the Deutscheman anvis 9 gift. ???

 

[FatBoy]

This happens out of a sling and coat when you don't put the buttpad in exactly the same spot every. It changes POI up to and sometimes more than a minute, depending on how the rifle recoils against what's under the coat. Get it on your collar bone after firing three from the pocket and you'll see what I mean. That's why a lot of shooters prefer to leave the rifle in their shoulder the entire string. Too much or too little face pressure on the cheek piece will induce horizontal stringing, even if your shoulder placement is perfect each time. That's why we readjust the cheek piece each time we build the initial position and get NPA. I wonder if you're rifle is loaded due to either shoulder or face tension. Also, if you haven't already, roll your thumb to sit on top of your index finger. wrapping your thumb over the stock can cause all manner of fuckery when group shooting.

this isn't apples to apples when it comes to bipod shooting but it's really ,really close and may explain your shift.

 

[TheGerman]

This happens out of a sling and coat when you don't put the buttpad in exactly the same spot every. It changes POI up to and sometimes more than a minute, depending on how the rifle recoils against what's under the coat. Get it on your collar bone after firing three from the pocket and you'll see what I mean. That's why a lot of shooters prefer to leave the rifle in their shoulder the entire string. Too much or too little face pressure on the cheek piece will induce horizontal stringing, even if your shoulder placement is perfect each time. That's why we readjust the cheek piece each time we build the initial position and get NPA. I wonder if you're rifle is loaded due to either shoulder or face tension. Also, if you haven't already, roll your thumb to sit on top of your index finger. wrapping your thumb over the stock can cause all manner of fuckery when group shooting.

this isn't apples to apples when it comes to bipod shooting but it's really ,really close and may explain your shift.

The shoulder part makes sense because most of this happens when I'd shoot a string, all very tight and great follow through/recoil management and then get off the gun. Reload, let it cool, etc and do it again. Great follow through/recoil management, tight group, yet....1+ inches POI from the last group even though I didn't adjust anything.

The dot drill shift is either my head pressure or shoulder.

 

[FatBoy]

My zero going from the bench to sling and coat is 3 MOA different. Doesn't take much to move your POI .25 - .5". 1" is a bit . Any chance you have the buttplate touching bone or the chest skin is being pulled differently between groups?

 

[TheGerman]

[QUOTE="j-huskey, post: 7282268, member: 83"]Unless your face movement is giving you the tiniest of scope shadow that you are missing seeing....
Just a thought. But, I've caught myself doing the shadow effect shooting a thermal when wearing a helmet and the edge of the rhino hits the eyepiece and I move head just enough to blow the shot. Doesn't happen when I dump the helmet, and I dont have the option of moving the scope because the eye relief is a bit short for shooting nv helmet. Jmhe[/QUOTE]

Ding ding ding.

This is it. Tried today and made a note to pay attention to absolutely everything as I went. I think the issue was introduced when I changed scopes from a 6.5-20 to the 7-35 and initially installed the scope set up for eye relief while prone at at max range. Somehow in there the LOP adjustment on the MRAD wasn't right and when shooting on actual terrain, instead of my flat garage floor, the up/down angles start to mess with the distance your shoulder/face are from the optic as opposed to when you are perfectly flat; we all know this, but this caused the problem. I just had to finally realize it.

Adjusted the LOP and eye relief today to get me in the middle of the range so I could adjust back/forth as the terrain changed to ensure I was looking perfectly through the optic. Don't think I would have even seen that I was getting scope edge on a smaller powered optic it was that small, but it was there.

Once that was adjusted, sighted in and got off the gun. Put 10 1 inch circles on the board and ran the drill. 9/10, and the 2nd to last was the slight miss and I knew it the second I pulled the trigger as I was really unhappy with the rear bag position.

 

[TheGerman]

Well, Christmas IS coming.... ? I'm ok with a used in afg by the Deutscheman anvis 9 gift. ???

So, you want to be a gangster?

Let's talk about your future.

 

[Greg Langelius *]

Regarding bipod feet digging in over a sequence of shots, try bringing along a Frisbee and placing it under the bipod feet.

Greg

 

[Terry Cross]

Ok. Question for you both.....

@j-huskey said issue might be shooter creeping into the scope shadow causing POI shifting for a shot or shots.
@TheGerman said some changes were made to minimize above stuff and then killed a bunch of dots.


We used to teach a lot of things to help shooters stay away from the dreaded shadow because it was a definite POI issue on old school scopes. "Old School" meaning when most mainstream scopes didn't have adjustable parallax or super critical/shallow parallax depth. Super easy way to miss, especially when under stress and/or in a hurry.

Now days, I am under the impression that if the shooter has a parallax adjustment on their main optic and take the time to confirm it is GTG for upcoming shot, their head position can be compromised up to and including getting into shadow without inducing a POI change for that shot. Basically you can't even purposefully get the reticle plane to visibly move against the target plane if you tried.

I know we want to stay away from shadowing for other reasons like image quality, etc. if possible but how far off base am I on the above?

Legit question. I'm here to learn when possible but I'm pretty inbred.


./

 

[TheGerman]

Ok. Question for you both.....

@j-huskey said issue might be shooter creeping into the scope shadow causing POI shifting for a shot or shots.
@TheGerman said some changes were made to minimize above stuff and then killed a bunch of dots.


We used to teach a lot of things to help shooters stay away from the dreaded shadow because it was a definite POI issue on old school scopes. "Old School" meaning when most mainstream scopes didn't have adjustable parallax or super critical/shallow parallax depth. Super easy way to miss, especially when under stress and/or in a hurry.

Now days, I am under the impression that if the shooter has a parallax adjustment on their main optic and take the time to confirm it is GTG for upcoming shot, their head position can be compromised up to and including getting into shadow without inducing a POI change for that shot. Basically you can't even purposefully get the reticle plane to visibly move against the target plane if you tried.

I know we want to stay away from shadowing for other reasons like image quality, etc. if possible but how far off base am I on the above?

Legit question. I'm here to learn when possible but I'm pretty inbred.


./

Good question; the short answer is that I'm not sure. Scope mechanics is probably the easiest way to get me to fall asleep, but I know there are some that could go over mechanics, glass composition, coatings and whatever for hours.

I'm actually curious about an actual answer too. Maybe parallax was turned out 97% of the way yet the way I was looking through the optic/whatever caused scope shadow increased the parallax enough to make the error? Has to be something with the optic as it didn't happen in between groups, it only happened right after a 'reset' where I came off the gun; yet the subsequent shooting would all group on the center of the 'new' POI.

I get what you're saying about the parallax, that if its tuned out of the scope and the reticle is on the center of the target, how did it shift due to your reticle not really being where you think it is.

 

[j-huskey]

@TC, I cant answer your question.

Reread Deutchmans response about eye relief and once corrected, problem stops.

It would seem, if the eye relief is too long, you dont have a perfect scope picture (which you wont have no matter how nice the glass) and you know well, imperfect picture and imperfect application (bc imperfect picture), imperfect result.

I would hope you, in your instructional capacity with the finest equipment and fine shooters you have, would run this experiment for us and educate us....
Please, TC !!! I asked nice...

 

[j-huskey]

I'm close to agreeing with Chris (fatboy), about shoulder placement and head pressure causing the shift, just enough,
But,
After running the same group of dept snipers in training for 20 years, I have seen some blown dot drills because npa was off just enough to cause what Chris said, but fixed it the student rebuilt for each shot being a first shot. Generally see the blown shot when speed is involved and there's just enough bipod torque to destroy npa and move the shot.

And an unconscious struggle to find the "lost eye relief" as Deutchman described, could create head pressure enough to disturb npa just like bipod or bag torque. Just sayin.

 

[Terry Cross]

@j-huskey
Well you're no damned help!

I don't trust myself on a lot of things and that is why I asked.

From what we can tell, this seems to be pretty close to true but I have definitely not done any systematic tests.
I have a stupid accurate .223 bolt gun that might get drafted for some play tests. Maybe at night with white light to minimize any chances of POI shift from sunlight changes.

The reason I wanted your feedback is because we are educating officers in the Basic Certification classes about shadowing the exact same way we used to so they will understand why it can be a problem. Explain to them that the older scopes had factory set parallax and no means of adjustment. Explain to them what limitations that brought to the table. Then explain to them how to counter it with consistent head/eye position with no shadow. Look them in the face and make sure they are tracking with what was explained.

Once we make damned sure they are understanding parallax, I make sure they know how to quickly get rid of it (almost all come in with adj. para on the scope these days) on their new fangled scopes.

My premise is that they will quite often get fucked on a reasonable body and gun position when setup due to the terrain, buildings and vehicles dictating a lot of allowable choices. If you are stuck with no option but having to sustain a shitty position and can make your optic forgive the head/eye position, the shot should still be money.

I am open to any opinions, debate, wisdom, nuggets, epiphanies, etc.


./

 

[Terry Cross]

@TheGerman For what it's worth, I see exactly what you allude to all the time when shooting control groups with rifles before shipping them.

I print out a target with 3 squares on some 110# index from SamsClub. Each rifle has to shoot 3 consecutive sub 1/2 MOA groups back to back on one piece of paper before shipping. That way I know I have a healthy rifle and the recipient knows I'm not cherry picking groups.

On average, I will take 6 rifles to be test fired at a time which will get me a minimum of 18 groups for that session. Even if I have a stellar day with small averages, I see the damned shift you are referring too. Small group, ......scratch my balls and sip water.....shoot next group with same damned rifle, ammo etc. and another small group but good chance in a different position in relation to the next aiming point.

I suck at shooting groups so I'm likely doing something stupid between groups.

Sorcery like that shit is why I shoot dots instead of groups with my own gun. Take the best shot I can make on a dot, get off the gun, walk a few feet, re-build my position, shoot another dot, ...repeat. I have WAY more confidence in my zero when looking at a row of dots I just shot at.

Sorry. All the above ramble just to say that I see it too. Pisses me off.

.

 

[j-huskey]

USAMU/Sniper School, when unc went to the parallax adjustable M3A, still taught correcting for shadow, and through the current scope iterations still teaches it. And because all the equipment I've seen in the last 5 years, through departments, indicated the need to teach it, so I still do.

Looking for scope shadow with new students generally is where I find their parallax isnt set right.

And the thing I see that annoys me much, is other instructors who started these guys on a flat range prone, with the scope set at the highest power, have screwed their charges when they have to move to that bad position you describe.

Got a lot more to say about this....

 

[j-huskey]

So, with a 3-18 or 5-25, or worse.... I have a test for my guys and they hate it.

Flat range, make it a perfect as you can, no stress.... dots, on 3x, 9x, and 18x...
Or 5x,10x,15x, and 25x.

And you and they find that wonderful setting on 18 or 25 sucks. So the scope moves until they can physically adjust themselves to the powers...

Then, we move from prone perfect to prone disrupted and stressed, and we might have to make one more scope move. Then, ......
It ain't prone anymore, sitting, kneeling, half kneeling, standing, bipod, tripod, rope, window sill, until they know where they have to adjust themselves to the rifle to make that f'd up position brain pan shot.

All the little gremlins come out doing it that way, and scope shadow and a tiny parallax glitch gives you the miss.

I've seen yours and the Deutscheman's poi shift b4. Its definitely me, bacause I can get up, mutter as I walk around, come back and rebuild the position with npa and back on.

As long as I build the position around npa, I have my greatest successes. And in the topic above, about recoil management and npa,
If I have npa and consistent recoil say up 3" and left 4, then I know everything else is pretty consistent.
And as long as I can rebuild and shoot a consistent group or consistent dots with consistent 3up and 4left on recoil, I'll take it because it means I have a level of consistency and confidence I'm going to hit the dot, or make that group.

Got a lot more to say on that too.

 

[j-huskey]

I've seen schools where the instructor tries to force you into a specific shooting "position" so recoil doesnt move the sight off target.
I've seen body mass that did not allow it at all and those people almost ruined by "that class".
I've seen custom 7500$ rifles that didnt fit and wouldn't allow that "position".
I've seen the body mass people with the 7500$ rifle just about shit when we started altering their rifle to fit them.

All of that has to fit to guarantee npa in any position the shooter may find themselves in. Until it all fits, training these guys is a nightmare.

One of my best training aids is a Winchester model 67 single shot 22lr iron sight rifle, and using standard NRA high power prone and sitting positions to start with. That seems to get the point across the quickest. Ymmv...

 

[FatBoy]

I understand what you mean about shadowing in old scopes but I haven't seen much difference in modern scopes when shooting at or beyond 100y. If I was shooting an old fixed Unertl and parallax was set for 250m, they would be definate issue. I admittedly don't shoot many dot drills as my rifles burn up barrel too quick.
BUT I have always used shadowing as a tool for making sure my head was in the same spot each time when I have a rifle with a scope set up for bench shooting and I go flat prone or to a barricade, etc. An even shadow all the way around the outside tells me I have no parallax even when the image isn't focused into the reticle. Now, I am not shooting dots in this case either. generally KYL racks, etc. but this works, especially speed shooting something that bleeds. (talking brown 4 legged shit here)

Though without shooting that scope myself, I believe that the shadowing isn't the issue on a properly adjusted parallax free scope. The head position that caused that shadowing, or a variation of shadows, would have head tension on the stock different each time. Turn the power down to get a bigger pupil and see if it goes away. If it does, scope. If not, position would be where I focused my attention.

Like JW said, you really want to see if its parallax or body position put the iron sights on and shoot apperature. You can shoot TINY little groups off a bench with irons once you figure out how much "ring" around the target works for you.

 

[FatBoy]

I forgot to ask, do you wear glasses when you shoot? Prescription or otherwise?

 

[j-huskey]

Had the opportunity this a.m., to test scope shadow on a S&B 5-25, a nxs 2.5-10, a nxs 5.5-22, and one atacr. Both nxs are new mil/mil. Three shooters. One shooter owns 3 S&B 5-25's...
S&B seems to have it more noticeably. All the others have shadow effect to the three of us.

I know my older S&B pmii 3-12's and 4-16's have it. Verified that yesterday on them. The department older 4.5-14 Leupolds are guilty.
Ymmv.

 

[FatBoy]

so properly adjusted for parallax, they shifted POI with shadows?

 

[j-huskey]

Yes

 

[FatBoy]

No shit. Learned something new today. I'm curious why this happens as the reticle doesn't move on the image at all. I'll pay closer attention when I have the power cranked up, which is 90% of the time.

Thanks for checking this today.

 

[FLEric308]

@TheGerman

Have you looked at your trigger press and grip pressure? Are you jumping on the trigger trying for an equivalent group or changing grip pressure as you press the trigger? Without watching you shoot it is kinda hard to diagnose.

 

[j-huskey]

@FatBoy,

Talked with TC last night. It's real clear that with the better glass, to get scope shadow, you have to have your head in a less than optimal place behind the scope....
So, from hipower days, you and I know that minor change in recoil management can change poi .
So...... until we get more time to play with this, not sure the exact cause of the poi shifts. Last two days tests, forcing scope shadow, the bullet movement was more sideways, which sounds more like head pressure. There were a couple went high low, but, that again could be head pressure.
Damn cotton field keeps getting in the way since we started this discussion. ?

 

[FatBoy]

Thinking a little more about this today and I'm back to head tension. I have shot next to F Open guys who would have to have shadowing, as they use 30+ magnification and barely touch the rifle. Yet they pile in (usually 18-19) 20 sub-MOA shots at all distances to 1k with a high percentage of Xs.

This takes the position out of the equation. Once the scope is set up and they are zero'd for prevailing conditions its essentially a return to battery rig and all they need to worry about is wind.

I wonder how that MRAD would shoot with a flat plate up front and a bag rider?

 

[supercorndogs]

Ok. Question for you both.....

@j-huskey said issue might be shooter creeping into the scope shadow causing POI shifting for a shot or shots.
@TheGerman said some changes were made to minimize above stuff and then killed a bunch of dots.


We used to teach a lot of things to help shooters stay away from the dreaded shadow because it was a definite POI issue on old school scopes. "Old School" meaning when most mainstream scopes didn't have adjustable parallax or super critical/shallow parallax depth. Super easy way to miss, especially when under stress and/or in a hurry.

Now days, I am under the impression that if the shooter has a parallax adjustment on their main optic and take the time to confirm it is GTG for upcoming shot, their head position can be compromised up to and including getting into shadow without inducing a POI change for that shot. Basically you can't even purposefully get the reticle plane to visibly move against the target plane if you tried.

I know we want to stay away from shadowing for other reasons like image quality, etc. if possible but how far off base am I on the above?

Legit question. I'm here to learn when possible but I'm pretty inbred.


./

Paging @koshkin. He might be able to give some insight into this question. I was under the impression you could affect POI even with parallax adjusted correctly, but I don't understand why, other than different cheek pressure moving POI around.

 

[koshkin]

Paging @koshkin. He might be able to give some insight into this question. I was under the impression you could affect POI even with parallax adjusted correctly, but I don't understand why, other than different cheek pressure moving POI around.

If your parallax is adjusted correctly for the dialed W/E, eye position behind the scope is not supposed to make a difference to the POA. If this issue continues, try to see if you see the same thing at a lower magnification setting.

Most of you are better shots than I am, so I am going to refrain from commenting on the non-scope related aspects for the most part. That having been said, most of the time when I see groups shift around, it ends up being tracked down to inconsistent loading of the bipod and/or inconsistent follow through.

Inconsistent follow through is typically related to NPA issues.

ILya

 

[Terry Cross]

If your parallax is adjusted correctly for the dialed W/E, eye position behind the scope is not supposed to make a difference to the POA. If this issue continues, try to see if you see the same thing at a lower magnification setting.

ILya

Thanks for posting Koshkin. Your expertise is appreciated.
This helps me feel better about what I have been feeding FNGs in a class environment.

I have to pay really close attention or I will look through the wrong end of the scope, so my technical prowess is somewhat limited.

./

 

[NineHotel]

Rimfire shooting will help you understand better the relationship between POI and pressures on the rifle. In smallbore league, at 50 feet we shoot one shot per bull. You are changing windage and or elevation hold on every shot. Shooting from position, with irons, the POI is of course related to hold point, but many other factors. Pressures on the rifle, pressure changes when you execute the trigger squeeze, all things that effect POI. It transfers over to center fire as well, but with less than half the barrel time, center fire is more forgiving in many respects. Vertical though can be an issue based on how much recoil your WS generates, hence the reason 6mm in a heavy rifle shoots so well in field shooting/varied positions.

We were at the range last week and came across a stack of rimfire bench rest targets that had been shot recently in an indoor match at the club. Scopes, benches, and changing bulls every target - guess what - us sling/iron shooters, that have some mastery of consistent pressures when changing from bull to bull, shot with about 1/3 the dispersion of POI these bench guys did.

I learned this lesson the first time I tried indoor 50M rimfire bench shooting to test some ammo; I was amazed at how poorly and inconsistently the rifle shot. It was not the rifle.

 

[dumbbell]

I've noticed this the last 2 months or so after I went back to shooting dot drills. When I zero, i take all the time in the world and really perfect my breathing, npa, and all of that. I can dial my zero in and repeat it with no zero shift day after day, as long as I'm shooting the same target and under the same lolly gagging time constraints. Then I shoot a 5 shot dot drill in 20 seconds, and all of my shots are consistently a tenth off to the right. My issue seemed to be a bit of head and neck tension when holding uber still for those zero shots, where when shooting dot drills or stages, I get an acceptable sight picture and pull the trigger. So I'm like mr Terry now, I shoot a dot drill to confirm zero, as it seems to be more of my "match" zero. Hope this helps, Greg

 

[slick19]

To me, this sounds like an issue I have been having. I have had a terrible time trying to shoot groups with other people's rifles (shooting team), I would get a good group, make an adjustment, shoot, then shoot another to confirm. the POI would then shift in whatever direction but make a great group. I also had issues with paralax. I would adjust the paralax unti lthe target was perfectly clear, but there would be shift of the reticle upon testing the paralax setting. To make the paralax go away I would have to make the target fuzzy. What I found out is that my diopter was not adjusted perfectly. I have a really hard time focusing the diopter due to having pretty good (and young) eyes. I had to use a tip that I found here, and set targets at specific distances, and adjust the diopter and paralax until I was able to get the target and reticle in focus, and no shift from the reticle upon testing the paralax.

Put a little more simply, it sounds like the diopter is not set right, and your paralax is also not correct due to the diopter being off. The diopter being off will bring the target into focus when the actual focal planes are not aligned.

just my .02

 

[wade2big]

Have you shot a 10 shot group to see if it fills in the blanks. You may find out that you arent having a POI shift at all. You may not be seeing the whole picture at once using a five shot grouping. In other words, the 10 shot group may match your 5 shot groups if you were to overlay them.

Try it and let us know.