Kestrel/Dope/Vel

[Dan636]

I need to pick some brains with the issue I’m having with my dope/Kestrel/apps

Start off. I built a 6mm Dasher for PRS matches.
My round.
Berger 105 VLD HUNTER
Lapua brass neck turned just high spots about 70-80 percent
Cci #450 magnums
.001 neck tension
Varget powder
Powder-32.450 grains

Load Development
Magnitospeed Vel - Avg 2939 FPS 10 shots
SD- Best 1.4 with 10 shots. Avg is at 2.1-4.1 with 10 shots. That’s .020 off lands.

Seating depth testing was at 300 yards.
.010 , .020 , .030 off of lands. .030 was the best with a 1.250 group.

Zeroed at 100 out 5 rounds threw the same hole.

I went to a match sat. It’s running good getting impacts.
Shooting a KYL rack at 1100. No impacts. I don’t have issues shooting 1100. Walk away wondering what was going on. Only stage I didn’t impact on.

Get home wondering. So I go out and do a test. I put up a target at 600 with a waterline. I shoot a group of 5 shots. They all hit way below water line. About 9”. Three group and 2 I broke the shot badly. But still in the same area.
My dope should be 3.1 mills. My group was under an inch at 600.
So I dial until I get center impacts. My dope is 3.5 at 600. So I start shooting steel. Hitting the 2” repeatedly. Dope is on point.
So I go in check my Kestrel. All data is correct. So I change my vel until it’s 3.5 mills. It says 2835 FPS.

I check my ballistic AB app. Says the same. For 2939 3.1
I check my StrelokPro app. Says the same. I change them to the 2835 and they say 3.5.
So I shoot about 80 rounds yesterday. Trying the correct Vel and dope. No impacts. Changing back to the 2835 FPS dope. Dead on at 420 and switching over to 600 dead on.
Do’s anyone have any input into what might be going on?
I’m running a MPA , surgeon action, rock creek barrel one and 7.5 twist.
NightForce ATACR 7x35x56
Sphur mount.
There is a match on sat in San Antonio I’d like to make. But need to get this sorted out first.

Oh. And I’d did change all sensitivity settings and got the same read outs etc on the magnitospeed to double check it too.

So at 1100 yards
E-9.1 is with my supposedly correct velocity of 2939

E-9.97 is with the 2835 velocity that yields me center impacts.

I’m stuck at the moment. Hopefully someone can shed some light on what’s going on. I’m going to go back to the range tomorrow and see what the incorrect velocity dope do’s at 200,300.

 

[Dan636]

Sorry. Picture went crazy I guess when uploading.

 

[One1Bravo]

 

[Subwrx300]

I need to pick some brains with the issue I’m having with my dope/Kestrel/apps

Start off. I built a 6mm Dasher for PRS matches.
My round.
Berger 105 VLD HUNTER
Lapua brass neck turned just high spots about 70-80 percent
Cci #450 magnums
.001 neck tension
Varget powder
Powder-32.450 grains

Load Development
Magnitospeed Vel - Avg 2939 FPS 10 shots
SD- Best 1.4 with 10 shots. Avg is at 2.1-4.1 with 10 shots. That’s .020 off lands.

Seating depth testing was at 300 yards.
.010 , .020 , .030 off of lands. .030 was the best with a 1.250 group.

Zeroed at 100 out 5 rounds threw the same hole.

I went to a match sat. It’s running good getting impacts.
Shooting a KYL rack at 1100. No impacts. I don’t have issues shooting 1100. Walk away wondering what was going on. Only stage I didn’t impact on.

Get home wondering. So I go out and do a test. I put up a target at 600 with a waterline. I shoot a group of 5 shots. They all hit way below water line. About 9”. Three group and 2 I broke the shot badly. But still in the same area.
My dope should be 3.1 mills. My group was under an inch at 600.
So I dial until I get center impacts. My dope is 3.5 at 600. So I start shooting steel. Hitting the 2” repeatedly. Dope is on point.
So I go in check my Kestrel. All data is correct. So I change my vel until it’s 3.5 mills. It says 2835 FPS.

I check my ballistic AB app. Says the same. For 2939 3.1
I check my StrelokPro app. Says the same. I change them to the 2835 and they say 3.5.
So I shoot about 80 rounds yesterday. Trying the correct Vel and dope. No impacts. Changing back to the 2835 FPS dope. Dead on at 420 and switching over to 600 dead on.
Do’s anyone have any input into what might be going on?
I’m running a MPA , surgeon action, rock creek barrel one and 7.5 twist.
NightForce ATACR 7x35x56
Sphur mount.
There is a match on sat in San Antonio I’d like to make. But need to get this sorted out first.

Oh. And I’d did change all sensitivity settings and got the same read outs etc on the magnitospeed to double check it too.

So at 1100 yards
E-9.1 is with my supposedly correct velocity of 2939

E-9.97 is with the 2835 velocity that yields me center impacts.

I’m stuck at the moment. Hopefully someone can shed some light on what’s going on. I’m going to go back to the range tomorrow and see what the incorrect velocity dope do’s at 200,300.

View attachment 7024165View attachment 7024166View attachment 7024167View attachment 7024168View attachment 7024169View attachment 7024170View attachment 7024165View attachment 7024166View attachment 7024167View attachment 7024168View attachment 7024169View attachment 7024170

When in doubt, check your equipment against another price of equipment.

• Verify Chrono data with another Chrono at the same time if possible).
• Double check inputs for Kestrel: sight height, zero height, BC and proper bullet profile selected (verify the numbers Kestrel has for your bullet like weight, length, BC etc.)
• Do a quick tall Target tracking test at 100yds with a ruler to confirm scope doesn't have a flat spot; I know it's a NF but shot can happen.
• Last resort, Chrono factory ammo with different bullet, shoot see distances, check ballistics output vs reality. If factory does the same thing (lower than calculated), it's likely your gun/scope. If not, it's something in the data entry in Kestrel. Or combination of both.

If all the above checks out, I'd say just live with it. As long as you can get a solution that matchs actual outputs at all ranges, it doesn't matter what the velocity "number" actually is. Either chrono is wrong and Kestrel right, vice versa, or somewhere in between; in any case, you still need good data and if you get Kestrel to line up at all distances, your good to go!

 

[Dan636]

When in doubt, check your equipment against another price of equipment.

• Verify Chrono data with another Chrono at the same time if possible).
• Double check inputs for Kestrel: sight height, zero height, BC and proper bullet profile selected (verify the numbers Kestrel has for your bullet like weight, length, BC etc.)
• Do a quick tall Target tracking test at 100yds with a ruler to confirm scope doesn't have a flat spot; I know it's a NF but shot can happen.
• Last resort, Chrono factory ammo with different bullet, shoot see distances, check ballistics output vs reality. If factory does the same thing (lower than calculated), it's likely your gun/scope. If not, it's something in the data entry in Kestrel. Or combination of both.

If all the above checks out, I'd say just live with it. As long as you can get a solution that matchs actual outputs at all ranges, it doesn't matter what the velocity "number" actually is. Either chrono is wrong and Kestrel right, vice versa, or somewhere in between; in any case, you still need good data and if you get Kestrel to line up at all distances, your good to go!

Yea. I have gone threw it all the data. I have not checked another chrono. But planed on asking my buddy to use his to check against mine. .
I planed on doing a tracking test tomorrow. To check that also.

 

[Olen_4504]

Seems basic - but the two time's i've chased crazy stuff like this it was:

1) incorrect range on the target (LRF was picking up the ground behind the target and not the target itself)
2) using the G1 BC instead of G7 hurt me once. i can't remember the specifics

check the battery's in the chrono and try someone elses

 

[_Windrider_]

How many rounds through the barrel?

 

[Dan636]

Seems basic - but the two time's i've chased crazy stuff like this it was:

1) incorrect range on the target (LRF was picking up the ground behind the target and not the target itself)
2) using the G1 BC instead of G7 hurt me once. i can't remember the specifics

check the battery's in the chrono and try someone elses

The burm begide the Target is no more than 5 yards. I did range it with my bushnell conX rangefinder to be certain on the range. Did double check that it was set on G7 BC.
I’ve checked with a few shooting buddy’s. They have gone over everything with me. Say that everything is right. But it has to be something in the data somewhere. Iv prob gone over everything 15 times to try and find it if so. But I can’t. And with 32.450 grains the VEL is right where it should be. A buddy who shoots this is running 32.7 and his VEL is AVG -2972 FPS. So I’m pretty sure the chrono is on point. Just can’t find what’s causing this.

 

[Dan636]

How many rounds through the barrel?

Just hit 1400 threw the barrel.

 

[Subwrx300]

Just hit 1400 threw the barrel.

If you haven't already chronoed again recently with the same lot of ammo you made, that would be my first check: same lot over two chronographs.

Can you post photos of your Gun Screen? Specifically BH, ZH, ZO screen? See photo below of menu I'm referring to:

 

[Dan636]

I did this at 600 because I don’t have 900 to 1000 available. Mine go’s transs at 1118.
Just did it in my Kestrel and it shows about 20 FPS Slower than I had put in at 3.5 mills. It is showing 2814 FPS.
Iv also been meaning to true my BC to at some point.

 

[Dan636]

If you haven't already chronoed again recently with the same lot of ammo you made, that would be my first check: same lot over two chronographs.

Can you post photos of your Gun Screen? Specifically BH, ZH, ZO screen? See photo below of menu I'm referring to:

View attachment 7024220

 

[AIAW]

My quick 2 cents...

A) Make sure that the atmospherics are updating your data (there in an option in the Kestrel to disable that).

B) May need to true up that BC.

EDIT: Saw that you posted about truing the BC. I would definitely do that (you are going to need a longer range).

 

[Dan636]

My quick 2 cents...

A) Make sure that the atmospherics are updating your data (there in an option in the Kestrel to disable that).

B) May need to true up that BC.

Yea. I make sure it is on live.
Been meaning to true the BC as soon as I can get to shoot 1000.

 

[Dan636]

Also I don’t know if I posted. But I did check dope at 420 and it was spot on with the vel of 2835. Which is 105 FPS slower than my chrono vel.

 

[Olen_4504]

you aren't using the BC for the 105 hybrids are you? instead of the 105 vlds?

edit: they are pretty close anyway. .278 v .275

side question: what made you pick the vlds?

 

[Subwrx300]

Looks right to me assuming the center of two 5 shot groups was EXACTLY dead center and scope centerline to bore center was measured properly.

The only issue that I've had with Kestrel that caused data errors was when creating profiles on app. It tends to default to 109y rather than 100yd zero along with resetting a few other items in the bullet profile. It's a pain but I have to edit one option and then go back to double check nothing else has changed, multiple times.

Check back after you've rechronoed and shot factory ammo to compare.

 

[Dan636]

Also I don’t know if I posted. But I did check dope at 420 and it was spot on with the vel of 2835. Which is 105 FPS slower than my chrono

you aren't using the BC for the 105 hybrids are you? instead of the 105 vlds?

edit: they are pretty close anyway. .278 v .275

side question: what made you pick the vlds?

No I’m using the correct BC.

Iv always had great load development with them. So I tried them when I got the Dasher.
They are spot on with my development. But once this barrel is burned out. I’ll be switching over to the coated 115 DTacs prob from here on out.