250 gr Berger Elite Hunter ballistic coefficients

[El Matavenados]

Hey all,
I did a fair amount of searching, and couldn't find a discussion of this. Sorry if I missed it!

Berger lists the g7 BC of the .338 250gr Elite Hunter as .351. I am sending it out of my 338 Sherman Short Mag at 2750 (measured on a LabRadar), 11" twist. I am using Strelok Pro for dope calculations, and that's where my problems started. I sighted in at 100, but when I took it out to 300 (farthest length available at my range), the POI was lower than I expected. Using the BCs published by Berger, I was hitting lower than I should have been. When I adjusted the BC to match performance, Strelok calculated it at .322. Today, I extended it out to 560 and 688 yards. The dope yielded by using a .322 BC was spot on at both distances.

Is that to be expected (because of my lower velocities)? Or are there other factors that I should consider?

 

[Gregg C]

Tagging in.

 

[FURMAN]

Hey all,
I did a fair amount of searching, and couldn't find a discussion of this. Sorry if I missed it!

Berger lists the g7 BC of the .338 250gr Elite Hunter as .351. I am sending it out of my 338 Sherman Short Mag at 2750 (measured on a LabRadar), 11" twist. I am using Strelok Pro for dope calculations, and that's where my problems started. I sighted in at 100, but when I took it out to 300 (farthest length available at my range), the POI was lower than I expected. Using the BCs published by Berger, I was hitting lower than I should have been. When I adjusted the BC to match performance, Strelok calculated it at .322. Today, I extended it out to 560 and 688 yards. The dope yielded by using a .322 BC was spot on at both distances.

Is that to be expected (because of my lower velocities)? Or are there other factors that I should consider?

I would say yes. Berger has historically been better than the competition at giving good average bcs but they can not cover every possibility.

 

[338 dude]

Hey all,
I did a fair amount of searching, and couldn't find a discussion of this. Sorry if I missed it!

Berger lists the g7 BC of the .338 250gr Elite Hunter as .351. I am sending it out of my 338 Sherman Short Mag at 2750 (measured on a LabRadar), 11" twist. I am using Strelok Pro for dope calculations, and that's where my problems started. I sighted in at 100, but when I took it out to 300 (farthest length available at my range), the POI was lower than I expected. Using the BCs published by Berger, I was hitting lower than I should have been. When I adjusted the BC to match performance, Strelok calculated it at .322. Today, I extended it out to 560 and 688 yards. The dope yielded by using a .322 BC was spot on at both distances.

Is that to be expected (because of my lower velocities)? Or are there other factors that I should consider?

Manufacturers do you stretch the truth because They know we all like a high BC look over this information it is published in Bryan Litz's book ballistic performance of rifle bullets third edition

 

[338 dude]

That is also my bullet of choice in my 338 if you can run multiple bc's they will be spot on if you only install one the average is 342

 

[FURMAN]

Manufacturers do you stretch the truth because They know we all like a high BC look over this information it is published in Bryan Litz's book ballistic performance of rifle bullets third editionView attachment 156181

You do know Bryan does Bergers bc testing??? Too many factors to give you a plug and play for every situation. Every velocity and twist. The calculator will actually have some effect on the outcome as well. Most calculators are great at getting it correct but they are not perfect either.

 

[338 dude]

You do know Bryan does Bergers bc testing??? Too many factors to give you a plug and play for every situation. Every velocity and twist. The calculator will actually have some effect on the outcome as well. Most calculators are great at getting it correct but they are not perfect either.

That's why I run multiple BC's and his information is spot on if there's any slight discrepancy I can usually resolve it by slightly altering the muzzle velocity we have targets at my range Strategic Edge in Chapel Hill Tennessee out to 1250 yards and I have validated trajectories out that far. I use the shooter ballistics program on my phone app Also my barrel twist rate is 9.3 And running approximately 2950 ft./s

 

[338 dude]

 

[Buster Hemlock]

Not saying you haven't verified it but make sure you have an accurate bore to sight height measurement. Being off by a small amount like a 1/4" or less will effect what the app is saying verse what you are seeing on target and leading you to believe the BC is off when it actually isn't. I've found Bryan's numbers to be pretty spot on and run his CDM's on my kestrel.

 

[elkaholic]

1:11 twist will lower it some too

 

[338 dude]

You do know Bryan does Bergers bc testing??? Too many factors to give you a plug and play for every situation. Every velocity and twist. The calculator will actually have some effect on the outcome as well. Most calculators are great at getting it correct but they are not perfect either.

The op stated a bc of 351 Litz has the average at 342

 

[El Matavenados]

Thanks for your input, guys, I really appreciate it. I have never used multi bc before, so I will look into that. I appreciate the photo of Litz' info as well.

So what adjusted BCs do you guys get with your velocities and twist rates? Bill, I see you TOF data, but I don't know how to convert it.

 

[Plinker147]

At 300 yards that you shot I just dont see a slight variation in BC making much a difference at that close of range. Sounds to me the it would be more likely your FPS is off. I shoot the 250elites in my RUM and BC has been on for me.

 

[elkaholic]

I agree that there are likely some other factors besides b c at work here. Scope calibration, scope height, velocity, etc. At 300 yards, .020 b c is pretty insignificant