Shape of my groups at 600yds?

[jaygorski]

Hello, I shot these 2 groups at 600yds, the 3.4" was last Sunday at our match, the other I shot this afternoon, both groups were shot coming off a clean barrel, and only the 3.4" group got a fouler/sighter shot, I did check the target today after the 1st shot and it was well within the group in the 7 ring, just thought I'd mention that. This load has shot many nice groups in the past and am curious as to why it's creating this particular shape, if it's something like shooting more foulers so be it, but if it's something else please tell me what it could be? The conditions at the range today was calm, no wind to speak of. Thanks!

 

[NV_Dmax]

Pure chance.
Shoot a 3rd group and report back.

 

[Fairchaser]

Check your action screws. You are getting some strange vertical. Either something loose on the gun or something going haywire in your reloading. You could also be right between a node on your barrel harmonics. Check your throat wear and see if you need to adjust seating depth.

 

[DirtySteve]

I would check every single screw on the gun. Scope mount and bases, and action screws.

 

[CharlieNC]

Those are fine 0.5 MOA groups, I would not try to read too much the shape for just a few shots.

 

[Mauser06]

First 2 shots always the high ones?


My rifle does that from a clean bore.

 

[Northridge]

Simply out of tune I suspect, how do you get to the point of deciding on a load before your matches? what procedures do you implement in your ladders?

Shawn Williams

 

[chkunz]

You my be simply seeing the satirical variation of what the gun does. Shoot a 20 shot group and you will have a better idea of what the gun is capable of for long run average.

 

[jaygorski]

Check your action screws. You are getting some strange vertical. Either something loose on the gun or something going haywire in your reloading. You could also be right between a node on your barrel harmonics. Check your throat wear and see if you need to adjust seating depth.

These are the only 2 groups where I got some vertical in the last few years, screws on custom rifles don't get loose, nor do they get loose on factory rifles, but I did loosen the rings and made sure they were tightened the correct way, hand tighten and then 1/4 turn with wrench, they were tight the first time. Here's a slightly different load with no vertical, like I said, I don't get vertical except if the barrel was cleaned. 2nd target was from our Match on Sunday, barrel was fouled prior to that match.

 

[jaygorski]

First 2 shots always the high ones?


My rifle does that from a clean bore.

Not sure, wouldn't the first 2 shots go low since there's less pressure due to a slight amount of oil in the barrel from cleaning?

 

[jaygorski]

Simply out of tune I suspect, how do you get to the point of deciding on a load before your matches? what procedures do you implement in your ladders?

Shawn Williams

When they shoot under .5" at 200yds and at least 4 out of the 5 are touching. Maybe I didn't mention this load shot a 1.482" not 2yrs ago, no stringing whatsoever.

 

[jaygorski]

You my be simply seeing the satirical variation of what the gun does. Shoot a 20 shot group and you will have a better idea of what the gun is capable of for long run average.

How bout four 5 shot groups? Make that 3, didn't take a pic of my last target from our last match ,it opened up to 5.6", had 4 in the lower left hand corner of the 10 ring that measured 3" and a flyer directly left in the 7 ring.

 

[chkunz]

How bout four 5 shot groups? Make that 3, didn't take a pic of my last target from our last match ,it opened up to 5.6", had 4 in the lower left hand corner of the 10 ring that measured 3" and a flyer directly left in the 7 ring.

Yes, that will work. Simply combine those groups into one large group and you start to see the capability of the gun and ammo. In your case it looks like a nice symmetrical group.

 

[Northridge]

When they shoot under .5" at 200yds and at least 4 out of the 5 are touching. Maybe I didn't mention this load shot a 1.482" not 2yrs ago, no stringing whatsoever.

A given tune window is not a constant, as bore texture changes over time, powder characteristics change over time, as brass gets more cycles on it the tendency of what the brass wants also changes, all of which will push a rifle out of tune or even in to tune. its not personal, tune windows can and do change slightly or even a lot just verify the shift and move on..

Shawn Williams

 

[coldboreshot]

Hello, I shot these 2 groups at 600yds, the 3.4" was last Sunday at our match, the other I shot this afternoon, both groups were shot coming off a clean barrel, and only the 3.4" group got a fouler/sighter shot, I did check the target todayView attachment 1267851 after the 1st shot and it was well within the group in the 7 ring, just thought I'd mention that. This load has shot many nice groups in the past and am curious as to why it's creating this particular shape, if it's something like shooting more foulers so be it, but if it's something else please tell me what it could be? The conditions at the range today was calm, no wind to speak of. Thanks!

I'm going to go out on a limb here, and some may disagree but I would check your parallax adjustment on your scope. At this distance, the change in point of aim is subtle enough to create this pattern. I've seen similar to this before. If you make the slightest change in position, the crosshair will follow if Lax is not adjusted properly.

 

[JFrank]

Hello, I shot these 2 groups at 600yds, the 3.4" was last Sunday at our match, the other I shot this afternoon, both groups were shot coming off a clean barrel, and only the 3.4" group got a fouler/sighter shot, I did check the target todayView attachment 1267851 after the 1st shot and it was well within the group in the 7 ring, just thought I'd mention that. This load has shot many nice groups in the past and am curious as to why it's creating this particular shape, if it's something like shooting more foulers so be it, but if it's something else please tell me what it could be? The conditions at the range today was calm, no wind to speak of. Thank you

You have a high percentage of shots leaking out of the main group. If not tune as Shawn pointed to than perhaps look in to ignition.

 

[jaygorski]

I'm going to go out on a limb here, and some may disagree but I would check your parallax adjustment on your scope. At this distance, the change in point of aim is subtle enough to create this pattern. I've seen similar to this before. If you make the slightest change in position, the crosshair will follow if Lax is not adjusted properly.

Pretty sure it's adjusted correctly, when I move my eye around the target doesn't move around.

 

[jaygorski]

A given tune window is not a constant, as bore texture changes over time, powder characteristics change over time, as brass gets more cycles on it the tendency of what the brass wants also changes, all of which will push a rifle out of tune or even in to tune. its not personal, tune windows can and do change slightly or even a lot just verify the shift and move on..

Shawn Williams

Same load shot 2 weeks before, measures 3".

 

[Ledd Slinger]

I noticed you seem to consistently have two fliers in the groups (new and old) which means the load was never really in tune. In that regard, I would say it is an ignition issue. Put a new firing pin spring in the bolt and also try different primers.

Also noticed you said the rifle has shot many good groups in the past. Although the load never looked to be in tune to me personally, you may have reached a point where you need to chase the lands and that’s why it’s getting worse. Once the fliers are dialed in, run a seating depth ladder test starting where you are now and moving the seating depths out in .002” or .003” increments to a total of about .015” or so.

 

[coldboreshot]

Pretty sure it's adjusted correctly, when I move my eye around the target doesn't move around.

I get what your saying but when you shift your eye position, its the reticle that should not move when the proper parallax is achieved. I'm seeing a repeat pattern in all your targets. 3-2, 3-2,3-2 etc. That's not your load data so eliminate your reloading from this mix. There's no way your ammo is set up in your ammo box to accidentally produce this sequence unless on purpose. Either a fastener is loose somewhere or your reticle is dancing around on the target to shift back and forth with the shot placement or changes in your position on the gun that seem to repeat themselves. I hope you find your resolve.