Why either subsonic or above subsonic total travel

[madman4570]

Most probably know this but do some of you guys know why for utmost accuracy you either want a bullet traveling subsonic from out of the muzzle to intended target or above subsonic all the way to target? stop before going further and think ???

For us normal guys some might say a moot point, but for some in certain applications can be a big deal.

What is a Shock Wave of bullet flight?
Starting and staying subsonic.
When a bullet travels subsonic the shock wave ahead of it actually begins to flow out of the way dissipating before the bullet reaches it. The pressure waves that have been created, the bullet is always behind of it and the air stays at being smooth and clean.


Starting above but becoming subsonic
As a bullet that was initially fired above being subsonic becomes subsonic before target the shock waves catch up to bullet slapping it in the rear section (pressure waves), the bullet stability and accuracy is compromised.

Though with subsonic loads trajectory issues is another matter. Just kind of interesting to why one might use a .416 Barrett vs a 50 BMG being a sniper.(faster to target /no shockwaves)enhanced long distance.

[Griff]

Altitude, air temp, density, humidity, conditions, (initial bullet stability or rather, stability upon becoming trans-sonic) and bullet design all play critical parts in how the bullet handles the transition from super to sub-sonic speeds. I also believe terrain is a factor of no small influence.

[cshold]

Ya forgot spin drift & earth rotation

[Griff]

Ya forgot spin drift & earth rotation

Those are "big picture" factors that play in any ultra-long range shooting, not just trans-sonic stability!

[BrentD]

Ya forgot spin drift & earth rotation

Those are "big picture" factors that play in any ultra-long range shooting, not just trans-sonic stability!

for ultra longrange, you need to consider inter-planetary alignments as well.

[madman4570]

Good points you guys.

I just thought is it cool you have this bullet that is moseying along its way and hurry hurry don't let Mr. Pacman catch ya and smack your bottom causing disruption. But that big old slow guy out of the shoot who cares in at least that regard I am taking my take but Mr. Pacman is going after someone else. Ahh good clean air.

[cshold]

Ya forgot spin drift & earth rotation

Those are "big picture" factors that play in any ultra-long range shooting, not just trans-sonic stability!

[cshold]

Griff, an accurate subsonic DOPE table just has to help...

[Griff]

Ya forgot spin drift & earth rotation

Those are "big picture" factors that play in any ultra-long range shooting, not just trans-sonic stability!

for ultra longrange, you need to consider inter-planetary alignments as well.

Ok, maybe I was thinkin' just for extreme long-range? Ultra is farther, right? Remember, I'm a CAS shooter, long range is like 50 yards, really long range is maybe a 100!

[BrentD]

I think ultra long range is like shooting at the moon - you know - Davy Crockett style.

[Canuck Bob]

Considering there is more undetectable dark matter in the universe than the stuff we can detect surely there is a resulting influence on trajectory. In my experience the number one impact on long range accuracy is me. Give me a 1000 yard champions rifle and I am sure I couldn't hit a sheet of plywood twice and honestly call the shots.

The first time I put 5 into a pie plate at 200 yards offhand with my 32 Special you'll hear the bragging in Texas!