What causes groups like this ?

[Bill Norris]

Hard to imagine but sometimes swapping stocks simply affects the way a rifle groups. Not claiming to know why or how this occurs but in a podcast "Believe the Target" with Erik Cortina and Tim Sellars, over towards the last segment Tim actually goes into this somewhat and discusses the weight ratio difference above and below the line of bore. Adding weight to the stock was one of the things he mentioned that would help change that ratio.

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[gunsandgunsmithing]

Hard to imagine but sometimes swapping stocks simply affects the way a rifle groups. Not claiming to know why or how this occurs but in a podcast "Believe the Target" with Erik Cortina and Tim Sellars, over towards the last segment Tim actually goes into this somewhat and discusses the weight ratio difference above and below the line of bore. Adding weight to the stock was one of the things he mentioned that would help change that ratio.

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That center of gravity relates to positive compensation. It very much is A factor in tuning but not the only factor. He and I agree for the most part on tuningvbut there's simply more to it than PC is all.

 

[searcher]

I’ll ask this also. I know form and consistency is important from reading years worth of threads on here. I’m not going to argue but why does so much emphasis get put on bench shooting or any shooting when the rifle doesn’t recoil until the bullet leaves the barrel. That is correct isn’t it ? When practicing dry firing which i believe is very important looking for any reticle movement if there is none it should translate into the same movement with a live round until it leaves the barrel correct ? I also understand a flinch is bad as your moving before the rifle goes off or before it gets down the barrel

Technically, this is correct. But that is assuming that ALL external influences introduced by changes in how one is gripping the rifle, how it is positioned on the rest, cheek weld, etc. are EXACTLY the same from shot to shot. If one bears on the rifle a bit more from one shot to the next, even though the shot looks good through the scope at the break of the trigger - the impact point will change. Even a change in friction on the rifle rest surfaces which the rifle slides over during recoil will affect point of impact. Dry firing is a great practice to attain trigger break timing and to know when one flinches (badly), yet everything else also has to be as "perfect" as the cross hairs on target.

 

[Deleted member fkimble@charter.net]

How do you set your parallax?

Frank

 

[Bill Norris]

That center of gravity relates to positive compensation. It very much is A factor in tuning but not the only factor. He and I agree for the most part on tuningvbut there's simply more to it than PC is all.

In this particular segment I don't think he was relating to P C. He was relating more to high frequency vibrations when he was discussing this portion of his test.

 

[DLT]

How do you set your parallax?

Frank

I focus until I get a clear image then I move my head around looking through the scope making sure the target isn’t moving off reticle.


BOTTOM RIGHT TARGET !!!! Just shot this from a whistle clean barrel. I moved the scope up so not to shoot out my aiming point with a fouling shot. First shot went in the middle of the target above of course. I then moved it back down so it’s holding zero and tracking at 100 I would say. Shot 2 was the highest, 3 hit closest to center and don’t know which of the other two was 4 and 5. Again first 5 out of a clean barrel. This was shot off my Caldwell br rest and a different rear bag. It shot good but I was not comfortable at all so it’s a wonder it shot as good as it did.

 

[gunsandgunsmithing]

In this particular segment I don't think he was relating to P C. He was relating more to high frequency vibrations when he was discussing this portion of his test.

I've seen the video. too Bill as well as spoken with him.. and also, I'm not sure how that relates to cg, but cg absolutely affects pc. As I said, he and I very much agree but he puts a lot more emphasis on PC being the driving force of tuning than I do. Guns can shoot and tune at top or bottom of bbl swing but PC is only possible on the upswing...which supports my position, but I'm also not saying that PC has no value. To the contrary, I prefer tovtune to the upswing when possible but I've won with both tunes.

 

[DLT]

I built a 4" Long x 1.5" tall ( Tapered ) x 5/8th Wide ( V-shaped, at Bottom, W/ rounded edges ), Oak, "Toe Tracking Runner" for my, Leather Protecktor Bag that, Runs almost Paralel to the Bore. That Plus, Jammed 107 SMK's, get Me into, the 2's and 3's with My, 6 XC. Take a Look at what, the Bench Rest shooters "Toe Area" of their Rifles look Like, on youTube. ( I made a sheet Metal, Bracket for the Front and used, a Long Screw to Secure the Back, to the stock).
I get NO Vertical of my Groups, Now, just Round "BugHoles", with this, Homemade, Toe Runner. Good Luck !
My Pillar Bedded, H-S Precision stock, HAD way too MUCH, Toe Angle towards, the Pistol grip !

Send a pix for fun

 

[Homerange]

I’ll ask this also. I know form and consistency is important from reading years worth of threads on here. I’m not going to argue but why does so much emphasis get put on bench shooting or any shooting when the rifle doesn’t recoil until the bullet leaves the barrel. That is correct isn’t it ? When practicing dry firing which i believe is very important looking for any reticle movement if there is none it should translate into the same movement with a live round until it leaves the barrel correct ? I also understand a flinch is bad as your moving before the rifle goes off or before it gets down the barrel

It's not that simple.

If recoil sensitive, every shot is let off with a different muscle state of tense which impacts grouping.

First you need to overcome flinching and the easiest way to do that is sissy bag up with some padding between the butt and your shoulder. Just a few layers of toweling is sufficient to take the bite out of recoil and reprogram the subconscious that it's not gunna hurt.
Then just shoot and shoot and eventually muscle memory becomes relaxed to recoil even to the point you can dispense with any padding as the body has become relaxed and accustomed to it.

When there....you have achieved a repeatable recoil acceptance state and groups improve as you are no longer tensed expecting a belting at the bench.
Everything else with your shooting platform needs to be right too and it pays to analyze technique also where I have only been able to obtain best groups front and rear bagged.

 

[jxb]

Horizontal then vertical dispersion after scope adjustment would suggest the scope is suspect.
Some shooters I've seen here gently tap their scopes after any adjustment to settle them.

Where's the popcorn emoji ?

If I needed to tap my scope after any adjustment it would be going in for repair or I'd simply replace it. Yes I have sent some in for repair due to adjustment issues and they were repaired. No more of that silliness.

 

[jelenko]

I’ll ask this also. I know form and consistency is important from reading years worth of threads on here. I’m not going to argue but why does so much emphasis get put on bench shooting or any shooting when the rifle doesn’t recoil until the bullet leaves the barrel. That is correct isn’t it ? When practicing dry firing which i believe is very important looking for any reticle movement if there is none it should translate into the same movement with a live round until it leaves the barrel correct ? I also understand a flinch is bad as your moving before the rifle goes off or before it gets down the barrel

The rifle must start to recoil as soon as the bullet starts to move. There is an equal force pushing the rifle back that is pushing the bullet forward.
If it didn't, there would be no difference in POI from free recoil and holding the rifle.

 

[clams243]

I would try to get someone who is an experienced shooter to test fire your rifle at same distance and load and see what happens. just a thought

 

[DLT]

I would try to get someone who is an experienced shooter to test fire your rifle at same distance and load and see what happens. just a thought

If anybody is following this and is around the annual bulls eye ground hog/egg shoot area let me know. I don’t know any experienced shooters where I am. Pretty much me and couple others are on our own

 

[RabbitSlayer]

I shoot almost exclusively from a bench with a atlas or harris bipod. I have tried many techniques. My best results so far are a thin pad under the bipod. Its a kitchen floor matt from Target. Mildy load the bipod. Its going to slip if you do more than take up the slack. I also pull the gun into my shoulder firmly, which is a bit controversial, but recommended by snipers hide. I believe what he says is correct. On a heavy gun with mild recoil you can get away with a light touch, thumb on the side, barely holding the gun. The more recoil, the more you need to pull back into your shoulder, wrap your thumb around the grip, load the bipod, and drive the rifle.

Having the bag fully compressed by the stock is important too. If you are squeezing a lot to adjust elevation it can cause vertical. I just ordered an adjustable rear bag base from mark and sam after work for this. Currently I adjust the tilt on my stable table. A bipod with a screw type adjustment instead of notches could do the same thing.

The only thing I haven't really tried is a board or something to load against. Even if it shot awesome, it is not practical for prairie dog hunting with rapidly changing shot angles, so I have no interest.

This stock has so much lead and epoxy in it and shoots so soft it doesn't really care about anything.

 

[DLT]

If anybody is following this and is around the annual bulls eye ground hog/egg shoot area let me know. I don’t know any experienced shooters where I am

I shoot almost exclusively from a bench with a atlas or harris bipod. I have tried many techniques. My best results so far are a thin pad under the bipod. Its a kitchen floor matt from Target. Mildy load the bipod. Its going to slip if you do more than take up the slack. I also pull the gun into my shoulder firmly, which is a bit controversial, but recommended by snipers hide. I believe what he says is correct. On a heavy gun with mild recoil you can get away with a light touch, thumb on the side, barely holding the gun. The more recoil, the more you need to pull back into your shoulder, wrap your thumb around the grip, load the bipod, and drive the rifle.

Having the bag fully compressed by the stock is important too. If you are squeezing a lot to adjust elevation it can cause vertical. I just ordered an adjustable rear bag base from mark and sam after work for this. Currently I adjust the tilt on my stable table. A bipod with a screw type adjustment instead of notches could do the same thing.

The only thing I haven't really tried is a board or something to load against. Even if it shot awesome, it is not practical for prairie dog hunting with rapidly changing shot angles, so I have no interest.

This stock has so much lead and epoxy in it and shoots so soft it doesn't really care about anything.

Is that a 13b protektor bag ?

 

[RabbitSlayer]

Is that a 13b protektor bag ?

Yeah, with heavy sand.

 

[bozo699]

That’s a troubling concern. The groups aren’t bad but if I had a doubt about a scope I’d just switch to another if you have one.
I never hesitated to ask a friend of mine whose skills are near identical to mine, to shoot it and see what he gets.
A spare scope and a friend who shoots the same are surely cheap but maybe unobtainable.

Your 100% spot in M-61
I have a Sako 222 that shot small bug holes then all of a sudden it was a 1/2 moa and sometimes worse!… had a buddy shoot it that was a veteran shooter…… shot bug holes!… it was me I had developed a flinch not wearing proper hearing protection. Took quite a while to overcome it but I did.
Wayne

 

[Homerange]

Your 100% spot in M-61
I have a Sako 222 that shot small bug holes then all of a sudden it was a 1/2 moa and sometimes worse!… had a buddy shoot it that was a veteran shooter…… shot bug holes!… it was me I had developed a flinch not wearing proper hearing protection. Took quite a while to overcome it but I did.
Wayne

Interesting.
Do you wear earmuffs for anything else you do ?

Most of my sporters wear cans and used to not worry wearing muffs at the bench until one day wearing my radio muffs shot much better that I normally would.
That event a good few years back also opened my mind to how our subconscious gets programmed from previous painful events, where now when shooting groups I always wear muffs and the paper tells it's worth doing so.

 

[bozo699]

Interesting.
Do you wear earmuffs for anything else you do ?

Most of my sporters wear cans and used to not worry wearing muffs at the bench until one day wearing my radio muffs shot much better that I normally would.
That event a good few years back also opened my mind to how our subconscious gets programmed from previous painful events, where now when shooting groups I always wear muffs and the paper tells it's worth doing so.

No sir I hate muffs they get in the road. I do however wear ear plugs, I pack them in my pocket everywhere I go. Unlike most people shooting doesn’t physically hurt my ears unless I’m shooting something like a .357 or 30 carbine however obviously it does do damage and even though I wasn’t smart enough to realize it my body was telling me it was bothering me. I think your onto something I don’t shoot cans but I imagine there’s some concussion going on and even though it’s not bothering you in your mind your body says otherwise.
Wayne

 

[Homerange]

No sir I hate muffs they get in the road. I do however wear ear plugs, I pack them in my pocket everywhere I go. Unlike most people shooting doesn’t physically hurt my ears unless I’m shooting something like a .357 or 30 carbine however obviously it does do damage and even though I wasn’t smart enough to realize it my body was telling me it was bothering me. I think your onto something I don’t shoot cans but I imagine there’s some concussion going on and even though it’s not bothering you in your mind your body says otherwise.
Wayne

There's a considerable range of compact slimline earmuffs available these days, not to mention the various brands of sporting muffs with active noise cancelling.

I've been using the folding compact Peltor muffs for many years and started when doing lots of trap many years ago. Get a report or 2 from your side shooter from a wild swinging bird shot and it's not long before you get good ear protection and as we now know, not only do they prevent hearing damage but also damage to our subconscious which impacts on precision shooting.....just as much as does excessive recoil !