D.O.P.E Through Transonic, 6.5 140 Hybrid

[DownunderDeviant]

Hi All,
I am wondering what peoples experiences are with 6.5 140 Hybrids Bullet drop through the transonic region.
I use Applied Ballistics with the Custom Drag curve well as Geoballistics to get my data drop.
I recently shot 1115 metres (1215y) and got some really consistent data (6.63 inch 4 shot group) which matched up perfectly to my drag curve and Labradar bullet velocity.
Just yesterday i pushed it out to 1295m (1411y), and instead of 14.5 mil drop it got 15 mil (1920ft DA) . Elevation was reasonably consistent (7 inch vertical dispersion)
Wondering if any of you could share your experiences with pushing the 140 Hybrid through transonic?

6.5 Creedmoor
Bartlein Gain twist Barrel 1:9-1:8
26 inch
140 Hybrid
2840fps

 

[VaRandy]

PM to you.

 

[CASCADE SHOOTER]

You prob got pm this from VA randy, on your ballistic app you just need to true your ballistic curve this will adjust the fps or bc won't make sense but it will to the computer to follow the path your seeing impacts at

 

[californiasushi]

We've shot our 6.5 Creedmoor at a mile with similar specs as yours. 26" Bartlein, 140gr Hybrid @ 2823 fps and used our AB Kestrel with custom curve. We're at roughly 2,000 feet elevation and the DA was 4881 feet that day. The bullets were subsonic at a mile but were still impacting consistently. Solid hits on target (when we actually managed a hit on the full-sized IPSC). The elevation correction the AB Kestrel gave us was remarkably close, which was somewhat surprising since so many people say it's not a very good tool when you shoot past transonic. It easily might not be, but it worked for us that day. However, the windage correction the AB Kestrel seemed a little light but wind down range may have been greater than we estimated.

 

[sandwarrior]

My experience is about that of californiasushi with my 6.5 Creed. I didn't have a chrono so I don't know the starting speed, other than to say they werre 2 moa lower at 1k than the Hornady 143 ELD-X's. But, at one mile the groups were holding together. This at 60 deg. My Brunton said 4331 ft. Hum. 30% Baro 25.60. The groups at one mile were remaining tight. Not like some bullets I've seen right up to the transonic range where they hit close, then go through it and become 12 foot groups.

So, at reasonable altitutude, they transition well. As did the Hornady's. I don't have any data that's for a lower altitude though.

 

[sandwarrior]

I need to mention, my barrel is a 1-8" twist.

 

[DownunderDeviant]

Thanks alot Guys for answering my query, i went back out the other day, to reconfirm, and i got consistent drop of 14.5 mil when the Ballistic Comp was telling me 14.5 mil. Not sure what was going on last time, could have been any number of unforeseen things.

 

[6.5x47 Guy]

Thanks alot Guys for answering my query, i went back out the other day, to reconfirm, and i got consistent drop of 14.5 mil when the Ballistic Comp was telling me 14.5 mil. Not sure what was going on last time, could have been any number of unforeseen things.

Crosswind jump would be my guess.

 

[Clearlight]

Not quite subsonic but transonic . Three 140 Hybrids in a row at 1500 on a 12 by 12 .
Three shots are MT initial .