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Where would my little 6mm 115 D-TAC {Sierra} bullets go sub-sonic and would they withstand the transition? I launch them at 2650fps from a 1-8" twist 6x222mag.
Depends on the altitude, humidity, barometric pressure, temp. Quit being cheap, and spend the $10 on a real ballistics calculator.;);):D

Figure out what the tail angle is, and you'll have a decent idea. Or go shooting with a decent spotter. If the bullet really tumbles, you can usually see it when you're watching the trace in the air.
You'd drop sub, somewhere around 1380 yards.
 
You'll make that without any trouble.

Cheers
 
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Per post 20,

Humpy used a barrel that was made from a cut-down Palma rifle barrel that was worn out for its original purpose. 13" or 13.5" twist, IIRC. The 168-grain SMK has a shape that makes it over-correct for any trajectory perturbing influence when it is spun too fast. The 175-grain SMK does not and can handle the 10" twist. But that's not the same thing as saying a 10" twist is optimal for it. It will likely be optimal at some muzzle velocity, but one that is lower than .308 muzzle velocity.
 
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I spent 8 yrs in the Air force in the Radar field. Part of that as a weapons control tech. Used to know what supersonic speed was in relation to say an F4C, don't remember anymore! When I hunt big game I stay within the MPBR, max point blank range, of the load I'm using. Knowing what supersonic is serve's me no purpose at all. I understand that shooting extreme range require's a bullet to stay supersonic to stabilize. Sometime, more than I might admit, I like to plink at target's way beyond MPBR. Don't know if the bullet stays supersonic or not, only know if I hit it or not!
 
I wish they'd had grayscale photocopiers back them.
 
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Yes. It's like being in space. No penumbra.
 
According to Hornady's 4 DOF calculator, which uses their individual bullet Doppler radar-determined drag function, in a standard atmosphere, you'd need to have a muzzle velocity of about 3200 fps to be supersonic at 1600.
 
Hmm, I think I would have made contact with something way before 1600 yards. Sage rats are pretty tough to see much past 500 plus a lot can happen in the couple seconds between squeeeeeze bang and thwock.

RJ
 
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