ELD-M minimum velocity for “expansion”?

[Wachsmann]

My hard and fast rule is all cup and core bullets, VLDs, ELDM/X, ballistic tip Noslers, sierras, all those type are 1600fps. The ABLR you could go lower probably 1500 to 1400. Enough data to back up those out there seems like. Bonded 1800fps. These are all minimums.

 

[fruitnut]

You'll gain around 100FPS in the 28 nosler with the switch from 195's to 180's. And still gain BC.

I just killed an elk with the 180 ELDM at 2150fps impact velocity and performance was solid.

I like 2000fps as my minimum, but that has zero credibility or science behind it lol. Bullets just seem to work at or above that speed.

Do you think the 180 ELDM really has a G7 BC of 0.401? That would require a form factor below 0.8. Do you know how long that bullet is?

 

[Huntnful]

Do you think the 180 ELDM really has a G7 BC of 0.401? That would require a form factor below 0.8. Do you know how long that bullet is?

In a 1-8 twist I trued it at .4 G7 in my buddy's 28 Nosler. In my 1-9 twist 7-300 NMI it trued at .38

 

[dfanonymous]

Hornady has it around .391 and Litz has it about .360.

The screen shot below is Hornady's publications.

The .401 is on the box. Keep in mind that BC changes for different ranges.


Bullet length is 1.535ish tip to base.

 

[chav0_12]

Hornady has it around .391 and Litz has it about .360.

The screen shot below is Hornady's publications.

The .401 is on the box. Keep in mind that BC changes for different ranges.


Bullet length is 1.535ish tip to base.


View attachment 613315

Even with whatever the custom curve is from AB, if I remember correctly, the numbers seemed better with the 180 ELD-M than the EOL.

 

[Phil Rizzo]

If I shot a bullet and came up with true numbers based on my MV, elevation etc I would not pay much attention to Litz, H or anybody else.

 

[Huntnful]

Hornady has it around .391 and Litz has it about .360.

The screen shot below is Hornady's publications.

The .401 is on the box. Keep in mind that BC changes for different ranges.


Bullet length is 1.535ish tip to base.


View attachment 613315

Yes very true. I should clarify that I trued at 1000 yards. Beyond that I'm sure the BC's start dropping

 

[dfanonymous]

Even with whatever the custom curve is from AB, if I remember correctly, the numbers seemed better with the 180 ELD-M than the EOL.

I've never compared the two. While I have rifles in these chambers, I don't spend a ton of time in the 7mm/28 cal cartridges.

The custom curve is just the actual bullet flight rather than based on a drag model. Where there drag curve becomes more off is when your equipment is exceptionally different. That's why in the AB library you'll see the PDMs.

Which brings me to

If I shot a bullet and came up with true numbers based on my MV, elevation etc I would not pay much attention to Litz, H or anybody else.

I suppose it would be that simple. Whoever, everyone is always just "truing" to whatever they want to get data to line up. You true in errors.

The only way to use drag models and have data dead nuts to subsonic is to have multiple BCs.
Most hunters don't do that. Competitive shooters do.

That's the point of custom drag curves.

 

[dfanonymous]

Yes very true. I should clarify that I trued at 1000 yards. Beyond that I'm sure the BC's start dropping

I wasn't going to say anything. A 28 nosler with a longer barrel than the test barrel and, and a faster twist than Mach 2.25 publications can most definitely be closer to the box.

Again, not knowing any other information or errors trued in.

Frankly it doesn't matter as long as you're getting the results you want.

 

[Huntnful]

I wasn't going to say anything. A 28 nosler with a longer barrel than the test barrel and, and a faster twist than Mach 2.25 publications can most definitely be closer to the box.

Again, not knowing any other information or errors trued in.

Frankly it doesn't matter as long as you're getting the results you want.

Absolutely. Could definitely have errors involved. So I don't put a ton of weight into the trued numbers as far as preaching them as gospel.

I just get a good zero, constantly monitor MV, and make sure my stuff hits center at long range.

Scope tracking could be slightly off. Zero could be .1 high or low. So on and so on.

But if you start around .38 I think you'd be pretty close at 1000+ yards.