Odd dope

[Adam B]

I took my RimX with my new Bartlein Carbon fiber barrel out to the ranger yesterday again to stretch its legs. I initially did a 35 yard zero and it made one hole multiple times. My dope was .2 at 50, I dialed it and was .2 high, dialed .2 down to my zero stop and it shot dead bullseye. As I shot further out, 100, 200 and 300 my dope was off every time. My dope at 300 was 13.5 with my Kestrel and it ended up being 12.2. I am at a loss as to why this is.

 

[jbell]

Stupid question but is it off in the same direction at each yard line?

 

[Adam B]

yes, all the same direction

 

[Adam B]

My other RimX with the same ammo and a Proof carbon barrel is spot on with the dope with my Kestrel.

 

[jbell]

Have you checked the velocity of the two rifles? Sounds like the first possible cause. I know I'm saying the most obvious stuff...

 

[Adam B]

yes, I had my labradar out yesterday and they we the same

 

[jbell]

Maybe swap scopes?

 

[Adam B]

that was my thought as well

 

[jbell]

Probably the next logical step

 

[jbell]

What scopes are on the 2 rifles?

 

[Adam B]

Athlon Cronus 4.5-29

 

[jbell]

I'm interested in your results with the scope change

 

[drglock]

I’m at 1000’ above sea level and with my RimX using Center X @ 1098fps I’m 13ish mils at 300, at work and not 100% positive but I’ll check when I get home but I’m pretty sure I’m 13.2-12.9 depending on environmentals.

 

[hlee]

0.1 Mil at 35 yards is only 0.126 inches. The closer your zero range, the more precise your zero needs to be. It is easy to be off by a tenth of an inch in any direction and think that you are right on. Then it bites you in the ass at range.

 

[drglock]

0.1 Mil at 35 yards is only 0.126 inches. The closer your zero range, the more precise your zero needs to be. It is easy to be off by a tenth of an inch in any direction and think that you are right on. Then it bites you in the ass at range.

This is why I always use the DSF mode on my Kestrel for trueing up my 22.

 

[Adam B]

well I switched to a S&B 5-25 and it did the same thing, zeroed at 35 yards, shot one hole, dope was on at 100 yards and high at 200 yards. I am so baffled.

 

[Adam B]

I shot again tonight on paper and steel, dialed 7.7 to 200 and was easily hitting 2 inch steel plates as well as shot a good group, dialed 14.5 to 300 and hit 1 mil high on paper and steel. Dialed down 1 mil and hit 3 inch steel at 300 with ease. I am at a loss as to why my dope is spot on out to 200 but 1 mil high at 300.

 

[JGottschall]

Maybe your scope is not tracking. You should do a tall target test and at the same time check the tracking.

 

[Adam B]

I tried 3 different scopes, it tracks, my last one on it is a S&B

 

[PinesAndProjectiles]

Is the scope height over bore correctly entered?

 

[Adam B]

yep, I checked that as well

 

[PinesAndProjectiles]

Same muzzle devices? Probably not a brake but maybe a can on a 22.

The results are repeatable though, right?

 

[Adam B]

run a can on it and it is 100% repeatable

 

[Adam B]

I actually swapped cans off my other 22 and it did the same thing

 

[Adam B]

I figured it out, I changed my bore height to 2.4 but for some reason it changed it back to 2.1. After I changed it back to 2.4 everything lined up.

 

[jbell]

Awesome! Great lesson for all who followed this thread. Thanks for posting it! It just confirms that it's best to always check everything step by step.

 

[FromMyColdDeadHand]

What settings are you using for the Kestrel, out side of MV? Bullet length and BC? I've never gotten an online ballistic calculator to work right for 22lr. Never done it in real time at the range.

 

[Dolomite_Supafly]

Give me the particulars and I will run it through my Ballistic calculator.

 

[Adam B]

thanks but I figured it out

 

[Badjujuu]

Not to kidnap this post by the OP - ran into a issue today with the Kestrel (i think).

Zeroed my V22 with PST GEN2 5-25x50 MRAD using SK Long Range at 100 yards.

Kestrel called for 5.02U for 200 yards and 11.23U for 300 - the shots were spot on (i think it was more 5.5U and 11.5U but couldn't see the impacts on 6" and 8" steel. Wind was right on.

For shit and giggles i tried shooting at 50 yards paper and Kestrel called 1.63D - but the actual was 2.00D

That caught me off guard as since I don't remember being that much off, since i started to use it.

I know people have issues at longer distances, but mine was the opposite today.

For NRL22 I zero @ 50 and Kestrel is always spot on with other distances, but for next PRS match I wanted to zero it at 100. Wasn't expecting such error at 50......

18" MTU barrel, SK Long Range ammo, 2.5" bore height.

StrelokPro also said 1.6D for 50.....

Im gonna lose some sleep over this...

 

[littlepod]

Not to kidnap this post by the OP - ran into a issue today with the Kestrel (i think).

Zeroed my V22 with PST GEN2 5-25x50 MRAD using SK Long Range at 100 yards.

Kestrel called for 5.02U for 200 yards and 11.23U for 300 - the shots were spot on (i think it was more 5.5U and 11.5U but couldn't see the impacts on 6" and 8" steel. Wind was right on.

For shit and giggles i tried shooting at 50 yards paper and Kestrel called 1.63D - but the actual was 2.00D

That caught me off guard as since I don't remember being that much off, since i started to use it.

I know people have issues at longer distances, but mine was the opposite today.

For NRL22 I zero @ 50 and Kestrel is always spot on with other distances, but for next PRS match I wanted to zero it at 100. Wasn't expecting such error at 50......

18" MTU barrel, SK Long Range ammo, 2.5" bore height.

StrelokPro also said 1.6D for 50.....

Im gonna lose some sleep over this...

Are you positive you have a bore height of 2.5". That's pretty damn high for a PST above the barrel.

 

[Badjujuu]

I'll measure it again tomorrow but that's what I've been running so far....my 30mm rings are 1.45" /36.8mm high

 

[littlepod]

I'll measure it again tomorrow but that's what I've been running so far....my 30mm rings are 1.45" /36.8mm high

I'm running 30mm rings that are .92" high, with a 40moa rail, and my bore height is 1.95, so I guess you are probably correct at the 2.5" bore height.

Not sure your environmentals but plugging into Strelok with a 100yd zero and a 50 yard target I'm seeing down 1.8.

Zeroing at 100yards hits a lot of environmental factors, so maybe your 100 yard zero was also off a .1 or .2.

Also you said you hit the 200 yard 6" plate, at 5, but it was more like 5.5 which also shows that your BC/Velocity are off since your curve isn't quite right. Being off by .5mils is not an accurate curve.

 

[Badjujuu]

At 200/300 i could not see the impacts on the steel but I did put the 5 hashmarsk center on the target. Other people were shooting that same steel, so upon inspection it was impossible to see who's who. At the 300, Kestrel said 11.23 - it was more like 11.5 because I held over bit more (at that holdover i was using the black bar on the bottom of the reticle). I got 30MOA base.

I guess I have to mention that once I zero at given distance I don't dial up/down - I just use the holdovers (EBR7C)

Going to try hit the range this week and start from scratch, zero it at 50 and go to 100 & 200 yard target, do it on paper and dial in to see what's up.

In the Kestrel I was using G1 curve at 1106 MZ (SKLR). Using more scientific method of measuring the bore height gave me 2.42 inches

 

[littlepod]

At 200/300 i could not see the impacts on the steel but I did put the 5 hashmarsk center on the target. Other people were shooting that same steel, so upon inspection it was impossible to see who's who. At the 300, Kestrel said 11.23 - it was more like 11.5 because I held over bit more (at that holdover i was using the black bar on the bottom of the reticle). I got 30MOA base.

I guess I have to mention that once I zero at given distance I don't dial up/down - I just use the holdovers (EBR7C)

Going to try hit the range this week and start from scratch, zero it at 50 and go to 100 & 200 yard target, do it on paper and dial in to see what's up.

In the Kestrel I was using G1 curve at 1106 MZ (SKLR). Using more scientific method of measuring the bore height gave me 2.42 inches

I also found that the default BC in Strelok to be a bit high. I've found that with 22LR ammo, most of the time the BC is around .145. It's been a long time though since I've used Strelok. I upgraded to a Kestrel Elite and the Center-X customer curve is just perfect.

 

[Badjujuu]

Same boat, since switching to Kestrel Elite with AB I rarely go back to StrelokPro.

The BC in StrelokPro for SKLR is default of .176

I have been using G1 so far in Kestrel App but maybe I need to start looking into custom curve.

Question about Custom Curve......when I selected it shows BC of 1.000

Is that right?

 

[littlepod]

Same boat, since switching to Kestrel Elite with AB I rarely go back to StrelokPro.

The BC in StrelokPro for SKLR is default of .176

I have been using G1 so far in Kestrel App but maybe I need to start looking into custom curve.

Question about Custom Curve......when I selected it shows BC of 1.000

Is that right?

Yep since it's a variable BC that's been doped by AB using Doppler.

Then you just true the muzzle velocity. In the 4 lots of CX I've tested (24-26-28xx) out of Ace, Kukri and MTU barrels it generally has ranged from 1086-1095.

If you're shooting SK LRM, I think that hovers in the 1105ish range.

 

[Badjujuu]

Cool - i really do appreciate your feedback, feel like a dry sponge absorbing here. So thank you for that!

I don't have a chronograph, so been using what's on the box and or averages of what people been posting or whatever the app defaults are.

I shoot all different types of SK and Lapua ammo from my V22 and CZ455 - would you use the custom curve on all the ammo profiles in the Kestrel App?

Luke

 

[littlepod]

Yep, I'd use that custom curve for all Lapua ammo.

And if you don't have a chrono, basically get a perfect zero at 50 yards, then do 100/200 zero on paper, and true your velocity to what your dope says for 100/200. The curve should work. I've done this multiple rifles, Tikka, CZ, RPRR, and my Vudoo. When the curves don't work it's usually because a person's zero was off by .2mils and then they got like a 6.9 vs a 7.1 at 200 yards and that is a significantly different velocity.

 

[Badjujuu]

Cool, i got some homework to do next range trip. Looking forward to it. Sometimes going deeper into the weeds of things is intimidating but fun to unfuck things....

Will update how things went here after my range trip...

 

[Badjujuu]

Went out this morning - got a good zero at 50 yards with SK Long Range.

Weather - 8mph winds at 6:30, 43°, 29.22 SP, 70% Humidity.

Used the Custom Curve on Kestrel for the ammo..

Changed over to 100 yards and Kestrel said 1.60 - it was more like 1.65 so put that into DSF.

At 200 - Kestrel said 6.49 but I had to dial up to 7.20 and eventually 7.30 to hit center (i was using paper as well as 4" gong). Got couple good groups on paper and after that the 4" steel was getting hit each time (i had couple fliers).

I inputted the 7.30 into DSF.