Long range ballistics guru's???

[bboswell]

308
168 Hunting VLD
Scope height 1.8
2635 fps
100 yard zero

I use both Ballistic AE and most currently BallisticArc with its weather meter.

100, 300, 500, 600, 800 & 1000 yards have been shot. Ballistics charts are spot on to 800 but at 1000 it's a full minute low.

If I correct velocity for this I will be 2 min high at 800.

What would you do?

[-HIC-]

Have you verified kestrel readings at the target? I would correct for that range and condition and log it. The electronic tools are great but you should shoot from your logs. Any oncoming wind will push it low. Tools are great; however, shoot with your known dope. You need to know target conditions to figure out what is off at that range with a .308.

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[-HIC-]

Frankly, 11 inches low at 1k is not bad for that setup. I would log it and correct on your rifle side dope card. You are reaching out there for that fps and bullet.

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[-HIC-]

One other thought - You can try keeping the ammo in a cooler for constant firing temp. I would expect overpressure signs if the ammo is hot. However, the key is consistency throuout all phases. Does your brass show ejector marks or anything to help narrow down the issue? Again, if ammo heat was the issue I would expect you could go back to 300 and shoot a diff poi, just something to consider.

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[ahlongslide]

What's your estimated velocity at the target?

[-HIC-]

I guess one final thought - if you are shooting into a stagnant strait up boil of mirage at that range you will see a minute or more of target shift.

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[JakeGraves]

Adjust your BC. Also, assuming you are shooting the same direction for all ranges. If you are shooting east on the 1000yd and west for the 800, coriolis can be this far off.

[bboswell]

Have you verified kestrel readings at the target? I would correct for that range and condition and log it. The electronic tools are great but you should shoot from your logs. Any oncoming wind will push it low. Tools are great; however, shoot with your known dope. You need to know target conditions to figure out what is off at that range with a .308.

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I did not take the meter to the target, used at the shooting mat only but there was not a breath of wind. Shooting down an East Texas pipeline through tall pine timber.

Charts are great but we are about to gain 7500' of elevation so I need to try to get my dope in the electronics on as good as possible.

[bboswell]

Adjust your BC. Also, assuming you are shooting the same direction for all ranges. If you are shooting east on the 1000yd and west for the 800, coriolis can be this far off.

all shots were due north down the same 60' wide pipeline

[bboswell]

what's your estimated velocity at the target?

1225

[howabouttheiris]

1225

You sure about this?

My quick calculator shows it at ~1100. Just concerned if you do not stay hypersonic that you are dealing with the effects of it passing thru the hyper/subsonic boundary and being knocked out of stability.

[onetondodge]

Have you tried a different app? I use strelok pro. I like it over AB.

[bboswell]

Long range ballistics guru's???

You sure about this?



My quick calculator shows it at ~1100. Just concerned if you do not stay hypersonic that you are dealing with the effects of it passing thru the hyper/subsonic boundary and being knocked out of stability.

I'm not positive, that's what BallisticArc showed with true weather but AE show closer to 1150.

I really think the grouping was too good to be going subsonic though.

A rain shower was approaching quickly while we were shooting, is it possible a sudden increase in humidity could do thus?

[Mike D]

You sure about this?



My quick calculator shows it at ~1100. Just concerned if you do not stay hypersonic that you are dealing with the effects of it passing thru the hyper/subsonic boundary and being knocked out of stability.

Mine shows it at 1176 @ 1000.

What is your come up at 800 & 1000?


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[bboswell]

Mine shows it at 1176 @ 1000.

What is your come up at 800 & 1000?


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24.3
37.1 actual (36.1 per chart)