ELR question from the FNG...

[flyingfisherman]

First of all, I’d just like to say thanks for welcoming me to the hide and also the wealth of information available from tried and tested resources..

My question to Frank and his team is to do with ELR, something that is a completely new (but interests me a lot) area of shooting. I have spent my whole reloading life trying to shoot the highest BC bullets as fast as I can, so I can keep out of that transonic region for as far as possible, ive experienced shooting a rifle that was a true ’half minute’ gun out to 800 that then opened up to 1.5 MOA as the bullet entered the transonic range,

I made the assumption that accuracy was ‘toast’ once you hit this speed and that went for as the bullet got slower, until I started watching guys shoot 6.5 cal bullets way out past transonic speed with what looked like good accuracy in the ELR range..

So, the real question I have is: is a bullet less accurate in the transonic region than when supersonic? is the same bullet in sub sonic flight more or less accurate than in transonic? is the bullet only less accurate in transonic flight and that only matters if your target lays at a range where the bullet is in this transionic region? Does a bullet gain stability once that shockwave has moved to in front of the bullet and the centre of pressure has moved?

i know it’s likely to be a theoretical issue and I’m disappearing up my own ass thinking about it, but I’d be interested to hear some views about it from the members and all..

Cheers from the UK..

 

[phlegethon]

It depends on the bullet. Some are affected more by the transition, some very little. I’ve read that many of the modern very high BC designs also tend to destabilize more when going into transonic, but I haven’t found a detailed treatment. Perhaps it’s in a chapter of Litz’s books I haven’t reached yet.

 

[Steel head]

I think the #4 podcast (possibly #5) with applied ballistics had some interesting info on this.

I’ve seen bullets that seem to get interesting At transonic/subsonic but others that didn’t seem to care and kept chugging along with authority.

With a good twist things seem to be uneventful and promote happy times.

 

[Lowlight]

If you are shooting ELR odds are you are gonna be subsonic, the transition is a fact of the game.

It does depend on the bullet, and how fast you can push it, which Is why i say a little bit lighter is better because it keeps the speeds up.

There are plenty of tried and true bullets out there, not much mystery about it, you stick with the proven winner and then pick the weight that suits the cause