1000 Yard Velocity

[Thumper580]

Suggestions for muzzle velocity to get a 168 match bullet to 1000 yards and stay supersonic. Fired from a 308 bolt gun with 26" barrel. Thanks.

 

[nuclear_shooter]

I recommend using JBM - Calculations - Trajectory to figure it out.

Its also worth noting that the local speed of sound will vary depending on the density of the air, ie weather/altitude may help or hurt you.

 

[FLIGHT762]

I recommend using JBM - Calculations - Trajectory to figure it out.

Its also worth noting that the local speed of sound will vary depending on the density of the air, ie weather/altitude may help or hurt you.

^^^^^^^^^^^^^^^^^^This is the answer^^^^^^^^^^^^

I went onto JBM just to play with it and at Sea level @ 60˚, you will need to be well above 2800 FPS using a Sierra 168 OTM. I've read the Hornady 168 A MAX can work a bit better, but if you try to get a 308 Winchester with a 168 bullet well over 2800 FPS, you're straining your equipment.

 

[nuclear_shooter]

I don't recommend using a bullet that requires you to use max load to get where you need, just in case there isn't a accuracy node that high up. I think the 175's are the popular choice.

 

[Rem7targetactical]

I don't recommend using a bullet that requires you to use max load to get where you need, just in case there isn't a accuracy node that high up. I think the 175's are the popular choice.

^^^^^ This ^^^^^^ The 175 was designed for this, the 168 isn't a good choice for this task because of less BC.

 

[Rapidrob]

Yep, the M118 type bullet will get the job done. Even if it drops below super-sonic, it has the weight to fight light cross winds.

 

[woostri]

I always had the best results with the 175 matchking when I shot .308. Only shot 600 yards but was performed well.

--- aim small miss small ---

 

[Rprecision]

At 1k with 168's your conditions have a huge effect

If your tied to the 168 weight bullets, if I recall it was primarily the 168 Sierra Match King that suffered this transonic problem. If I recall it had to due with the angle of the boat tail. The a-max I have had first hand out shoot the SMK

175's work better for me, and if your after higher FPS check out the 155 class.

The problem with 175's is they can be hit or miss with 1/12 twist

 

[jkonzal]

I use the 155gr A-Max and if you run it at 2900fps, the velocity at 1K is still 1294fps. If you look at a comparison of wind drift and TOF (time of flight), you may find out that the 155 is a much better way to go.