HOW far will 7mm 168 gr remain stable in flight????

[relictrader]

Found a good 7 Rem VLD load but may be limited because avg MV is 2864 with Berger 168 VLD Hunting bullets.

I would need some math help to know how far it will shoot and still be stable in flight so that a yardage knob can be calcuated for it.

Gary

 

[500 meter ram]

I would think it would remain stable until dropping through the sound barrier.

 

[Ksmirk]

It's going to revolve around the twist in your barrel and getting out and shooting to get you an accurate drop chart. I have found that when a bullet looses it's RPM to keep it stable it'll go TU! I don't belive the when it falls below the sound barrier theroy, we were making hits out to 1100 with 168's in a 308 and they would fall below the sound barrier at around 950 if I recall. I shot a 308 that I built to shoot the 155 Palma bullets and used a 1-14 twist barrel, the 168's would hit start to loose RPM and start hitting sideways at 800, 900 yards 2 of 5 would hit sideways and at 1K they would all be printing cool little side bullet profile holes.

Think of a bullet like a top, as long as it has enough RPM it will stay upright and spin, as soon as the RPM drops what does the top do? Just my .02 worth for the day. Later,

Kirk

 

[Flybuster]

Only one true way to figure this out, pull the trigger.

 

[relictrader]

Thanks to Mark, for if one does not know where or how to find something someone will give a helping hand...

((JBM ballistics is a great resource: http://www.jbmballistics.com/))

It predicts your 168 will remain supersonic out to 1300 yards. After that it may or may not remain stable, it is difficult to predict. I'm pretty sure 1300 yards is well beyond the envelope you are thinking about so you're good to go...MARK


Thanks

 

[bingo1010]

i too do not subscribe to the supersonic unstability. this winter i shot my 284 win 162 amax (2950) out to 1 mile and shot a 12" group for 5 shots. 8 twist barrel

 

[Bryan Litz Ballistics]

Flying at transonic speed is very stressful to the stability of a bullet. Some bullets can manage the challenge (depending on barrel twist, air density, etc) and fly comfortably to subsonic speeds. Other bullets cannot remain stable at this speed and will either fly with large coning angles or tumble completely.

I agree with Mark's assessment above; with your 168's, you won't have any stability concerns until well beyond 1000 yards.

-Bryan