Does bullet stability drop of with velocity??

[rscott5028]

One more thought on bullet selection ...

Yeah ... I'm not sold on solid copper ... but I do like a bullet that won't totally blow up on impact and that will retain most of it's weight by the time it's done.

I wonder about standard grade projectiles at the sort of impact velocities that a 243 can produce (> 3000 fps). My view is that they tend to fragment at those sort of speeds and thats really bad for hunting.

Nosler says their Partion bullets are good from 1800fps -- unlimited.

That may be a little hyped up. But, I'm certain they'll hold up for the 243 win.

-- richard

 

[proload]

You indicated the 4th and 5th shots opened up the Scirocco groups. Is it consistently the 4th and 5th shot as in the barrel may be heating up and not stress releived? Or, are you saying 3 out of 5 are in tight and 2 are pretty far out there?

No, it's not 4 & 5 ... I think it was 1 & 3 that were wide (I know that the first shot was the furthest ... and no it was not cold bore or fouling shot) ... I was controlling the barrel temp. I don't think its that.

How well did the Noslers group?

I was ladder testing both Noslers, so group is not so easy to tell, but I got tight "sweet spots" on both loads. I'll be doing group testing next time I go to the range.

 

[load]

^^^This is how i've come to understand it as well, rotational velocity does not bleed off like translational velocity, your round should retain the majority of its rotational speed throughout the bullet flight.

But here is the Caveat, if your are experiencing bullet yaw on paper it's no big deal, but you throw that same amount of yaw on a game animal you may be setting yourself up for a serious bullet failure. As bullets are designed to obviously penetrate in as straight a line as possible, gyroscopic stability is a must, if your bullet either hits the animal with a slight yaw or yaws while in the animal you will tend to see unpredictable penetration. Your shoulder shot may end up somewhere in the ham etc (think of it as a deflection). Also at work are the mechanical forces on the bullet itself, being designed to impact at the nose, they don't tend to hold up with all of that force being applied to side of the bullet.

Just my .02.

look up bullets spin like tops on youtube. just to illastrated your point (i wouldn't recomend doing it) bullet fired at ice stops but still spins like a top

 

[rscott5028]

look up bullets spin like tops on youtube. just to illastrated your point (i wouldn't recomend doing it) bullet fired at ice stops but still spins like a top

Interesting. But, I don't get the relevance.

 

[proload]

Thanks guys.

I've had another look at the targets that I brought back from the range, and the bullets are definitely yawing ... no question about it ... I reckon that the center of the backside of the projectile is about 1.5 mm off-center from the point.

All the stability calculators that I've looked at confirm what I am seeing on paper.

Looks very much like the Nosler Partitions are the way to go for my barrel, and thats OK. They're a good bullet and will do the business on my target game species.

Thanks for all your input. I learned a lot.

Cheers