SUB OR SUPER SONIC??

PEZHEAD265

What is the top end of subsonic and the low end of super sonic in feet per second?

What is the trajectory of a subsonic 22 compared to a supersonic 22?Both are shot from the same gun and are the same weight bullits from a bench rest[vice]

Which one will shoot flatest at a 100 yds and why??

Can a 22 bullit go from sub sonic speed out of the muzzle and gain speed to become super sonic at a 100 yds??If so what happens to trajectory??

*Spelling

Rocky Raab

The speed of sound varies with temperature, but for general purposes, call it 1100 fps.

The slower round will drop more (assuming the same aim point and sighting) than a faster round simply because gravity works on the slow round longer before it gets to the target.

No, bullets cannot speed up after they leave the muzzle.

dakotashooter2

About 1117 fps is transition from subsonic, to supersonic. (5 x the speed of sound is hypersonic) Considering the differance could be 1 FPS to thousands of FPS trajectory could be the same (for practical purposes)where the two meet or have great discrepancy. When a bullet leaves the muzzle it is always at its fastest speed because with no pressure behind it air resistance begins to slow it right away. Basically all propulsion occures in the barrel so it cannot gain speed after leaving. Also note that a bullet also starts to drop immediately after it leaves the barrel. The arched trajectory we commonly see in drawings is a result of the bullet exiting the barrel above the plane of sight. It does not rise from the barrel then start to drop.

Tailgunner1954

NO, the bullet dosn't increase in speed after it leaves the muzzle (unless your shooting a gyrojet)
The bullet starts being effected by gravity the instant it leaves the muzzle. The reason it "rises" above the line of sight is that the barrel is pointing "uphill" relitive to the sights.
Using your 22 as a example,
IF the supersonic round stays supersonic, than it may be just group as nicely as the subsonic round. However the problem is when it slows down through the "trans-sonic" range the sonic pressure wave moves forward from behind the bullet to in front of the bullet it disturbs the bullets path in a random and unpredictable direction.
Long tange shooters also have to concern themselves with the same phnominon, IE making sure their bullet stays supersonic all the way out to the target.

PEZHEAD265

Thanks guys for the info.

stevecrea

I know this is bunk, but in high school a classmate told me that the 30-30 Winchester was the only cartridge ever made that actually accelerated after if left the muzzle of the rifle. This made it truly unique.

Just thought someone needed a laugh this morning.

All the best.

Nwcid

Real benchrest .22 shooters use ammo that is subsonic due to the trans-sonic effect Tail was talking about.

I shoot a lot of SS because of my silencers.