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Rifle Scopes Seven Scopes with Issues or Something Else

Interesting. I see the optic logic, but also where this could be bedding or lack thereof.
Edit: dang…an actual expert responded with similar speculation. Just call me Mr Redundant who needs to read the whole thread before tossing his hat into the ring. Sigh…haha
You’re deaf and type slow, it’s ok. 😜
 
I’d be curious if anyone has waited (to eliminate barrel flex etc) post drop. Meaning; drop the rifle, wait at least 5 mins and then shoot… I suspect barrel flex or internal turret springs are slightly compressing. Unfortunately if waiting the aforementioned time does “fix” it then it’s still unclear if it’s barrel or scope! I do also realize waiting any amount of time completely eliminates why this is being done in the first place but I’m curious to see what would happen.
 
I'd really like to see a video of your whole shot process for the 2 shots.

Just to throw out a contrarian opinion. We know if you have a loose hold prone or are not firm on the bag (bi-pod/bag) the shot will go high from the butt sinking in the bag. What I'd like to rule out is that your hold isn't changing from 1st shot to panned shot???? With a heavy comp rifle, mine are set up a little front heavy when balanced on the bag (especially with bi-pod on). So I'm thinking about my own process. I'm pretty sure my first shot after dropping on the bag I tend to guide the reticle on target with the grip & fore grip, then bring myself into stock. So bias towards free recoil first shot. Second shot when panning I don't think I back out of the stock, or in other words I use my shoulder to guide/pan to next shot. I think for me I'd tend to have a more solid pocket hold on the second panned shot.

My question to the brain trust is this. Does a heavy comp rifle shot free recoil of a bag shoot low vs. a firmer shoulder pocket hold????

Edit: My first shot (competition scars) my brain sees to much reticle movement and tells me "tighten that shit up". This is one of the reasons I've been shooting the 308 with 177's. Free recoil is not a good option.
 
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The bag is changing shape if you’re panning to the second shot. I’m leaning toward the bag variance between shots or your NPOA changing.
It’s hardly any rifle movement between the two diamonds. Try it out and see what happens.
 
I'd really like to see a video of your whole shot process for the 2 shots.

Just to throw out a contrarian opinion. We know if you have a loose hold prone or are not firm on the bag (bi-pod/bag) the shot will go high from the butt sinking in the bag. What I'd like to rule out is that your hold isn't changing from 1st shot to panned shot???? With a heavy comp rifle, mine are set up a little front heavy when balanced on the bag (especially with bi-pod on). So I'm thinking about my own process. I'm pretty sure my first shot after dropping on the bag I tend to guide the reticle on target with the grip & fore grip, then bring myself into stock. So bias towards free recoil first shot. Second shot when panning I don't think I back out of the stock, or in other words I use my shoulder to guide/pan to next shot. I think for me I'd tend to have a more solid pocket hold on the second panned shot.

My question to the brain trust is this. Does a heavy comp rifle shot free recoil of a bag shoot low vs. a firmer shoulder pocket hold????
I put the same pressure and inputs on both shots. I don’t and have never even tried the free recoil thing. No issue with it really other than I want to see the trace if I can, splash or miss on every shot possible shooting distance.

I do get what you’re saying and will see if I can upload a short video clip tomorrow of one two round run. If not I’ll send it to someone that hopefully can upload it.
 
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What is your bag filler?

Bigger, lighter poly or plastic beads popular in run-and-gun bags are going to roll and and take more reps to settle than dense, heavy black volcanic benchrest sand in a leather bag on top of a Bald Eagle.
 
What is your bag filler?

Bigger, lighter poly or plastic beads popular in run-and-gun bags are going to roll and and take more reps to settle than dense, heavy black volcanic benchrest sand in a leather bag on top of a Bald Eagle.
I’ve tried this with a heavy fill game changer and a get lite fill game changer. Same results with both. Both were the schmedium or whatever they call it size.
 
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Good thread.

Mechanical movement somewhere in the system. Personally doubt it is the scope. But it very well could be. And I’ll prove myself wrong with an analogy…

From the perspective of precision grinding and machining, like down to a couple microns, how you place parts, or handle fixtures and such you can see movement that can’t really be explained.
I just know that if you want precision then do every thing, exactly the same, every time. Or at least understand how what you are doing different effects the final result.

I look forward to seeing this thread play out! 👍
 
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Well when you mentioned it as barrel memory I wanted to figure out what it was because that didn’t make sense. After mentioning that it was a scope issue we began gathering results and compiling it so that it didn’t turn into a speculation fest.. so for data and more specific information the data and shifts have to be sufficient and thorough so that there are less emotions and more facts.
I have most scopes tested but waiting for independent results from a few others.
I’ll make an article once I feel there’s more objective data.
Is this similar to the testing that's done on Rokslide regarding scopes losing zero due to horizontal impacts?
 
I’ve done similar tests a few years ago. Along with a rubber mallet. The issue at first I assumed was optic, then optic mount. Ended up being unbedded chassis. Since then all my chassis have been bedded.

^^ seen the same and reported it here over the years in “chassis bedding” threads

I’ve never purposely dropped my rifle from 12” while transitioning, but I don’t baby them either so I’m sure it’s happened naturally…when testing chassis bedding I literally grabbed the stocks on all my rifles and swung the barrels into wooden benches so hard they left ~1/8” crescent dents and they wouldn’t move in any direction more than .1 at most, usually nothing…I still wouldn’t miss a 1” dot

I don’t go to the range much any more, but if I do and remember I’ll take a couple guns I know have been banged to hell and held and try this specifically
 
I think alot of the better shooters are shooting paper. Especially 1" dot drills and things like the SH and MDS sniper drill. They are great practice and you are right, paper doesn't lie. They would be reporting it. I know chad and francis zero after every day

The question is, if there was a shift why wouldn't it persist? If you zero at beginning of match and at end of each day, and see no change, or across days, then how is it explained? A tenth is within the noise elevation wise with most shots.

The only thing that makes sense IMO, is people abusing their equipment. I know exactly what they mean by letting it fall, say from position 3 to 4 on the PRS barricade. Its about 20" by spec. I can't recall anyone letting the weight of the gun just drop on a hard sand bag rested on a steel rail. You can do a controlled decent with the grip but most people, actually grab their bag and the gun with the support hand, especially if they are running a plate or attached bag.

IMO its no different than any of the above mentioned examples where we know you will get POI shift from banging your gun/optic around.


I was at box canyon this last go around and listened to the podcast where heckler and colon talk about checking zero after day 1 of a match (I’m paraphrasing here).

I did the same thing. I ran a 28 inch barreled 24 lbs tac class rig in 308 and I can 100 say I abused the ever living fuck out of my gun at that match. I was actually worried my zero had shifted near end of day one, but I went to the zero board and checked it…and nada. Shot one ragged 5 shot group hole and I absolutely was dropping that gun and running it hard. I run all my rigs pretty goddamn hard, and don’t think I’ve seen this phenomenon across any of the 4 rifles I run.

Mind you, this isn’t me saying “it’s not relevant and doesn’t happen” but it’s interesting so many people have polar opposite opinions about this stuff.
 
That's a pretty easy one to check. Just mount a visible laser on your scope. Look at the dot through your scope and see if it moves.
If it's not the scope, then mount it on your barrel, chassis or whatever and use the process of elimination.

P.S. Use a quality laser so you don't add another variable.
 
I was at box canyon this last go around and listened to the podcast where heckler and colon talk about checking zero after day 1 of a match (I’m paraphrasing here).

I did the same thing. I ran a 28 inch barreled 24 lbs tac class rig in 308 and I can 100 say I abused the ever living fuck out of my gun at that match. I was actually worried my zero had shifted near end of day one, but I went to the zero board and checked it…and nada. Shot one ragged 5 shot group hole and I absolutely was dropping that gun and running it hard. I run all my rigs pretty goddamn hard, and don’t think I’ve seen this phenomenon across any of the 4 rifles I run.

Mind you, this isn’t me saying “it’s not relevant and doesn’t happen” but it’s interesting so many people have polar opposite opinions about this stuff.
So this is more about it being dropped then shot. It shows low on paper. The next shot it’s back to normal. So if you beat the crap out of the rifle it’s reset back to normal after the last shot. So yea at the end of a match it would shoot it’s standard zero. I’m tracking what you’re saying. It’s just has me curious that it’s resolved after the shot following the drop.
 
It seems the answer is nothing you used was bedded, pad or otherwise so it’s that in a chassis

I thought one was, one wasn’t, but it wasn’t that most likely answers it as referenced above.

Thought it does play into the Rokslide test, so it tracks with what they did. However I think pad bed the chassis first
 
So this is more about it being dropped then shot. It shows low on paper. The next shot it’s back to normal. So if you beat the crap out of the rifle it’s reset back to normal after the last shot. So yea at the end of a match it would shoot it’s standard zero. I’m tracking what you’re saying. It’s just has me curious that it’s resolved after the shot following the drop.
What throws me for a loop on it actually being the optics, is the fact you dialed up and down and it changed nothing as you said.

I did the test today with a bedded chassis and did not experience the shift. However it was very limited amount of rounds and I wanna experiment a smidge more with a few different guns and optics before I begin to argue one way or another.

That said, I don’t drop my gun like that and I wouldn’t recommend it either. So it’s not something I “should” see in a competition or training.
 
Part of the Rokslide test is that the barreled action/chassis used for the test are bonded together so there can't be shift. There's a reason for that and I'm inclined to think @morganlamprecht is right on his suspicions. Side note, his (and others') posts about the unbedded chassis issue convinced me to order a Foundation.
 
I thought I read earlier you tried after the drop to dial the elevation away and back to the dope with no effect.

Have you tried with only holding over, so scopes always stay at zero?

Sorry if this was mentioned and I missed it.
 
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Be interesting to see more fixed scopes tested to compare.
 
Following for education.
Thoughts from the under-experienced: You seem to have eliminated a lot of variables already. From what I am reading you have done/eliminated the following:
Scope - multiple tried
Mounts - multiple tried
Barrels - multiple tried
Chassis - multiple tried - none bedded - Variable #1
Trigger - not changed - mechanical moving parts - Possible Variable #2
Bipod - You mentioned you can hear your bipod rattle - possible harmonics having an relationship to this? - Possible Variable #3
Bag - 2 fills tried, same bag size/shape - doubtful but could bag shape have an impact? - Possible Variable #4

Am I missing anything that has already been tried/changed to help solve this problem? Hoping to learn while watching this problem be solved.
 
@spooledup - Appreciate that you are running different rings. However, what are you torquing them to, and are you using a threadlocker and/or paint pen / nail polish?
They are all torqued to their respective values per manufacturer. I use blue on the ring cap screws and nothing on the base clamp.
 
Following for education.
Thoughts from the under-experienced: You seem to have eliminated a lot of variables already. From what I am reading you have done/eliminated the following:
Scope - multiple tried
Mounts - multiple tried
Barrels - multiple tried
Chassis - multiple tried - none bedded - Variable #1
Trigger - not changed - mechanical moving parts - Possible Variable #2
Bipod - You mentioned you can hear your bipod rattle - possible harmonics having an relationship to this? - Possible Variable #3
Bag - 2 fills tried, same bag size/shape - doubtful but could bag shape have an impact? - Possible Variable #4

Am I missing anything that has already been tried/changed to help solve this problem? Hoping to learn while watching this problem be solved.
Harris Bipod was also used along with no bipod attached at times.

Three different triggers/barreled actions were used.
 
Part of the Rokslide test is that the barreled action/chassis used for the test are bonded together so there can't be shift. There's a reason for that and I'm inclined to think @morganlamprecht is right on his suspicions. Side note, his (and others') posts about the unbedded chassis issue convinced me to order a Foundation.
Honest question.....what does the Foundation do that wound make it not have a POI shift if not bedded?
 
Honest question.....what does the Foundation do that wound make it not have a POI shift if not bedded?

The action inlets are cut specifically for the brand/action type and very tight fitting to the point of u usually have to squeeze the action down into them a bit

Not like a standard rem700 footprint chassis where pretty much any rem700 style action will fit because it’s just sitting in an oversized inlet held in by the 2 action screws

So you give up some flexibility for swapping rifle configurations around later, but it seems to be more consistently reliable
 
The action inlets are cut specifically for the brand/action type and very tight fitting to the point of u usually have to squeeze the action down into them a bit

Not like a standard rem700 footprint chassis where pretty much any rem700 style action will fit because it’s just sitting in an oversized inlet held in by the 2 action screws

So you give up some flexibility for swapping rifle configurations around later, but it seems to be more consistently reliable
Thanks this makes more sense now.
 
From reading about scope issues it seems ring manufacturers like using 18in/lbs as a spec but 25 usually doesn’t have a scope move. Then the scope mfg says you crushed the tube at 25.

Here’s a test to try. Loctite everything and repeat test. If it shows the same then do another test but this time after the drop turn your turrets up a turn and back down to see if there’s a change. it should point to something in the scope if there is no shift of poi without permabonding everything for the sake of science. Meaning the the adjustment went back to zero but if not turned something, spring, moved a bit causing the poi to move.

Wear marks on the erector tube or erector tube not being smooth enough is an issue with Leupold scopes, Al Nyhus has posted pics of ones he’s disassembled and polished smooth and then no more issues for what he does with them.


And people on here said dropping scopes was stupid and abusive yet there seems to be a problem that’s been ongoing.
 
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From reading about scope issues it seems ring manufacturers like using 18in/lbs as a spec but 25 usually doesn’t have a scope move. Then the scope mfg says you crushed the tube at 25.

Here’s a test to try. Loctite everything and repeat test. If it shows the same then do another test but this time after the drop turn your turrets up a turn and back down to see if there’s a change. it should point to something in the scope if there is no shift of poi without permabonding everything for the sake of science. Meaning the the adjustment went back to zero but if not turned something, spring, moved a bit causing the poi to move.

Wear marks on the erector tube or erector tube not being smooth enough is an issue with Leupold scopes, Al Nyhus has posted pics of ones he’s disassembled and polished smooth and then no more issues for what he does with them.


And people on here said dropping scopes was stupid and abusive yet there seems to be a problem that’s been ongoing.
How would it return to zero if the optic is sliding and twisting due to ring torque every time it’s dropped?

And no, this is not an ongoing problem and I have no idea how someone could think it is.
 
And people on here said dropping scopes was stupid and abusive yet there seems to be a problem that’s been ongoing.
While I'm not sold on the idea that this particular issue is a scope problem, I'd agree people are overly dismissive of the Rokslide stuff. Largely due to the guy who does the testing acting like a jackass 24/7. I do believe zero retention in high end scopes is not where we'd like it to be.
 
Think of dropping like the reverse recoil of a magnum spring pellet rifle. It will move in the opposite direction to what the rifle is designed for. I shoot a lot of the magnum air rifles and always chasing a zero after 100 rds or so. It’s either mount or scope moving. The scopes seem to hold well. I am having some success by epoxy mounting mount to rifle but scope still moved in the air gun mounts from time to time

In the Chassis built rifle I would either bond or tightly bed the action to the stock

I have not seen this type of movement in my well bedded fiberglass stocked bolt actions

Remember these are big tuning forks that any change in pressure or mechanical movement will change it’s tune
 
Being old as dirt I also remember our old swat sniper rifles, with HS Precision Stocks, would shift zero ridding around in the SWAT Bread Truck in the early 1980’d. I bedded them with a steel epoxy and they would settle down

My bedded rifles I use for teaching have Gen 2 and Gen 3 Vortex on them and I have not seen them shift like this. Hence I think it’s mechanical in either the stock or scope mount interface
 
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From these posts it seems like a common denominator is also the Remington 700 or clone action.

I would be curious to see the results using an AI action in an AI chassis or a Howa in one of the chassis that the original test that was done.

-Stan
 
This was my thought. I’m far from and expert on scope internals (or much else for that matter) but from my reading my understanding is that the internal tube has a spring that opposes a screw like function of the turret.

So, perhaps as you speculate, a hard downward force causes the spring to compress but not exactly return to its prior position. Then the recoil of the next shot shakes things up a bit and now it’s back to a precise zero.

In some diagrams I have seen of scope internals, a single spring is used to oppose both the elevation and windage turrets but I suspect this is on lower cost scopes and that the ones you have referenced have a separate spring for each turret.

I also understand that tkes very, very little angular shift to move .1 mil or so.

And, while I’m busy guessing (lol), I suspect that there is a practical limit to how strong a spring can be put in there and still allow ease of turret movement.

And yes, this is all pure speculation (uh…same as pulling it out of my ass haha)

Edit: dang…an actual expert responded with similar speculation. Just call me Mr Redundant who needs to read the whole thread before tossing his hat into the ring. Sigh…haha
Now that I've had some time to think about it, I would be very surprised if it was the scope. I can only see something like this happening in the scope if there are issues on the contact pads (where the turret stem interacts with the erector tube). Since it is witnessed with many different scopes that all design that interface a little differently, it is extremely unlikely. Besides, the way scope designs are tested introduces much more severe shock along the same axis and I just have not seen this shift.

I suspect it is something else.

ILya
 
How would it return to zero if the optic is sliding and twisting due to ring torque every time it’s dropped?

And no, this is not an ongoing problem and I have no idea how someone could think it is.
Agreed.
Too much grasping at the wrong straws.

The shock and stress from the vertical impact is not loading any of the screws, fasteners or attach points. Nothing in that mechanical chain is moving.

.
 
Agreed.
Too much grasping at the wrong straws.

The shock and stress from the vertical impact is not loading any of the screws, fasteners or attach points. Nothing in that mechanical chain is moving.

.
Terry if it’s not mechanical how do you explain it returning to zero? Not arguing. Just seems to me if it slight moves in opposite direction of recoil then returns to zero after some shooting it’s mecahical

When we were shooting non bedded Savages We found after putting in stock smacking the butt down on solid object would settle first rounds. If not it would take several rounds to settle the rifle. Then if taken out of the stock it would repeat if not taking the same procedure. Stan Pate taught me this and it works
 
Terry if it’s not mechanical how do you explain it returning to zero? Not arguing. Just seems to me if it slight moves in opposite direction of recoil then returns to zero after some shooting it’s mecahical

When we were shooting non bedded Savages We found after putting in stock smacking the butt down on solid object would settle first rounds. If not it would take several rounds to settle the rifle. Then if taken out of the stock it would repeat if not taking the same procedure. Stan Pate taught me this and it works
I didn't say it wasn't something mechanical. I'm just putting money on it having zero to do with scope mounts.

I don't know enough about the conditions to guess what the issue is but I definitely have opinions of what it isn't.

Starting with SH Cup and SH Bashes, we seen a ton of rifles slamming bipods into the ground hard trying to kill dots in under 5 or 6 seconds. That drill has been cleaned multiple times. We still run what I call Precision Stress Drills in LE classes that do the same from a standing start with rifle in hand. Lots of guns and scopes doing well when driven properly. I'm guessing those rifles are equaling or surpassing the vertical load and shock of dropping 12 inches onto a GS bag.

My guess is that it is not scope related either just from sample size of design and material variations.
 
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You know the original designer of the AI rifles was a world class shooter. I wonder if his bonding everything together was to solve these issues?
Scott Seigmund has stated that the bonding of the early AIs was due to the lesser machining quality of that time. With modern machining, AI says that bonding is no longer required. It’s why their latest releases are not bonded.
 
Scott Seigmund has stated that the bonding of the early AIs was due to the lesser machining quality of that time. With modern machining, AI says that bonding is no longer required. It’s why their latest releases are not bonded.
Those newer rifles that aren’t bonded have exhibited shifts that owners are solving by bedding/bonding.
 
From these posts it seems like a common denominator is also the Remington 700 or clone action.

I would be curious to see the results using an AI action in an AI chassis or a Howa in one of the chassis that the original test that was done.

-Stan

My AIAT and 2 buddies held like my bedded rifles, no issues

All bonded
 
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On mounts: I have seen cooky thing with mounts that could potentially explain this. It comes down to the clamp design and how much friction is built into it. Generally, in a well designed mount, zero retention should not be related to friction between the pieces, but I have seen this be all over the place.
 
What if the barrel length to recoil drop length leverage and the little bit of flex at the front of the receiver was enough to slip the action forward in the chassis the .001" or .0001" movements then the first round clips the action and lug back to it's normal place of operation. It would fit with the unbedded chassis idea. Ie. 28" barrel and a nominal .5" lug drop would be a 56 to 1 lever. doesn't take much to move things with impacts like described. Cool thread!
 
On mounts: I have seen cooky thing with mounts that could potentially explain this. It comes down to the clamp design and how much friction is built into it. Generally, in a well designed mount, zero retention should not be related to friction between the pieces, but I have seen this be all over the place.

If I’m following you correctly…what you mention is why I always fully seat all mating surfaces of rings caps and clamps before torquing screws to make sure they don’t tighten “artificially” from small misalignments, friction, etc before fully seating…and are only held by the respective clamping forces best I can manage

Having an uneven clamp/cap/mount just takes the right impact to shift it/settle it

I always thought of it like when unbolting 2 pieces that slightly misalign making the bolt feel tight…give one of the pieces a whack or relieve the pressure/misalignment and the bolt can spin freely with your fingers

I’ve also used a small amount of grease in the past on rails/clamp mating surfaces to make sure they’re able to slide together and fully seat before torquing, but I didn’t find issues leaving the grease out and just aligning by hand so I can’t say it helped, but it didn’t seem to hurt either