Help Analyzing Fliers

[bill123]

I shot this “Optimal Charge Weight” round robin this morning and am wondering about the source of the fliers.

Rifle: GA Precision 308, 1:11 twist, #7 contour, 22” Barlein barrel (about 250 rounds through it)
167gr Lapua Scenar bullets, .010” jump
Varget powder-same can
Laupa brass weight sorted in a .5gr lot., necks turned & trimmed, primer pockets uniformed, flash holes deburred
BR2 primers- same package

I shot 2 foulers of 41.0gr & 41.5gr. The other groups are 4 shots each, shot in a “round robin”. The fliers at 42.1 & 42.4 were the first 2 shots after the foulers. The flier at 43.0 was the last shot in that group. I’m mostly curious about the fliers at 42.1, 42.4 (inside the scribble) & 43.0 because they are so far from the rest of the groups and all low right.

I’m not arrogant enough to say that it’s impossible that I caused the fliers but they are awfully far off for me. I’m wondering what else might have caused them.

 

[jonbearman]

What kind of rest and rear bag are you using. Are you gripping the rifle hard or lightly or free recoil?

 

[bill123]

What kind of rest and rear bag are you using. Are you gripping the rifle hard or lightly or free recoil?

Shooting off a bench. Atlas bipod, lightly loaded w/ light grip on rifle. Using a "sand sock" type rear bag.

 

[Nowhere Man]

What I'm seeing are fliers of similar placement on the target which leads me believe it's on you.

 

[jsthntn247]

I see no fliers in you node of 42.4-42.7. Load at 42.5 and you are within the node. You will see another node around 44.2.

 

[bill123]

Nowhere Man: That's what I suspected. If I ignore the fliers (and called them on me) wouldn't I have a node around 42.7-43.0?

jsthntn247: The 42.4 flier is in the scribble above the number "42.4"

 

[Nowhere Man]

I can't see were you'd go wrong with 42.4 - 42.7 either. 43 looks to be were the shots start spreading out.

 

[savagedasher]

42.7 Is where I would work around. .01 plus or less. My self I would do a series of 2 shots at a smaller aiming point. I like a + for a aiming point. If you have vertical normally more or less powder will take it out. With two shot you cut down the factor of changing conditions. Larry

 

[chkunz]

Here is another thought and it is not a pleasant thought. Sometimes five shot groups are good enough with a very accurate rifle and good bench technique. But what if the fliers are not fliers? What I am saying is, what if you shot a ten or even a twenty shot group and you found a very uniform group that was just about two times the size of the five shot group and there were no fliers? With more shots the fliers just become part of the group. This would be disappointing but it would be better to know the truth than to be chasing the wrong thing. Again, just another thought and you may know enough about your situation to dismiss it.

 

[bill123]

Here is another thought and it is not a pleasant thought. Sometimes five shot groups are good enough with a very accurate rifle and good bench technique. But what if the fliers are not fliers? What I am saying is, what if you shot a ten or even a twenty shot group and you found a very uniform group that was just about two times the size of the five shot group and there were no fliers? With more shots the fliers just become part of the group. This would be disappointing but it would be better to know the truth than to be chasing the wrong thing. Again, just another thought and you may know enough about your situation to dismiss it.

Definitely something to consider. I'm leaning toward its me but once I settle on a charge weight, I'll try shooting a 10 shot string.

 

[dalej]

It took me a long time to appreciate Varget. Using load data from Sierra and Hornady manuals gave me flyers. Finally checked Hodgdon's on-line data. Max loads in Sierra and Hornady were less than starting loads on Hodgdon's site. Started filling the cases and rifles started to group without flyers.

Best way to test for accuracy is use a shooting rest and sand bags. Make sure rifle is in neutral when trigger is squeezed. Any inputs or attempts to steer rifle will result in fliers. I use a Rempel bipod on my F-T rifle but its a long way from the Atlas bipod.

 

[jcampbellsmith]

...Best way to test for accuracy is use a shooting rest and sand bags. Make sure rifle is in neutral when trigger is squeezed. Any inputs or attempts to steer rifle will result in fliers. I use a Rempel bipod on my F-T rifle but its a long way from the Atlas bipod.

+1. Can I suggest using a quality rest and shooting exactly the same test again? Regards JCS

 

[bill123]

...Best way to test for accuracy is use a shooting rest and sand bags. Make sure rifle is in neutral when trigger is squeezed. Any inputs or attempts to steer rifle will result in fliers. I use a Rempel bipod on my F-T rifle but its a long way from the Atlas bipod.

+1. Can I suggest using a quality rest and shooting exactly the same test again? Regards JCS

Thanks for the suggestion. Can you recommend one, keeping in mind that I will only use it for load dev?

 

[Drop Port]

I also shoot mainly from an atlas pod but all development is done off a BR rest. I've seen bipods cause problems at times on hard surface. Once you rule out the pod / rest it will make elimination easier. As stated filling the case can at times eliminate it. From where you are at there is a good chance you will hit the next node. When I hit the next node up in my 47L groups sucked in and the flyer went away.

 

[bill123]

I also shoot mainly from an atlas pod but all development is done off a BR rest. I've seen bipods cause problems at times on hard surface. Once you rule out the pod / rest it will make elimination easier. As stated filling the case can at times eliminate it. From where you are at there is a good chance you will hit the next node. When I hit the next node up in my 47L groups sucked in and the flyer went away.

Thanks. Were you getting fliers like mine, all in the same relative position to the main group or were your fliers more random?

 

[Drop Port]

I believe they were all low.

 

[bill123]

Thanks all for your help!

 

[M14AMU]

Up your charge!