Anomaly in 308 and 6.5 Creedmoor dope (308 is better)

[BradleyH]

After a range trip this morning, I discovered my 308 dope is superior to my 6.5 creedmoor. And I don’t know what is going on. To gather the dope below I used weaponized math due to not having a chronograph.

Specs:
AI AX
Factory 24 in, 308, 1/10
Win tactical 26 in, 6.5 creedmoor, 1/8

Factory Ammo:
6.5 Creedmoor Hornady 140 ELD Match
308 Hornady 178 ELD-X Precision Hunter

308 (Mils) Dope:
100 - Zero
200 - .5
300 - 1
400 - 2
500 - 2.9
600 - 4
700 - 5.9

6.5 Creedmoor (Mils) Dope:
100 - Zero
200 - .5
300 - 1
400 - 2
500 - 3.3
600 - 5.2
700 - 6.9
800 - 8.1 ( Range finder died and I did not mark my targets when I set them but I was pretty this was 800)

These loads were shot on two different occasions and ranges. I recently built a new range and the 6.5 Creedmoor was the flavor today. However they are both flat. And about a month apart in when the dope was gathered.

The weather was pretty similar, around 30 degrees. But today with the 6.5 I was battling the wind pretty bad. 20 mph with gusts up to 30mph. For the 6.5, targets 100 - 500 had the wind at 9:00, while 600 - 800 had winds at 10:30 -11:00.

600 wasn’t too bad but I felt like the wind was really giving me more fits than it should of. Past that I wasn’t consistently splashing on either side of the target. I will attach the 600 target to show how the vertical spread (after the first bottom right impact) was good but horizontal was very erratic. And once I went past 600, it felt like things went to hell in a hand basket.

Other notes. The 6.5 barrel is fairly new, I have about 160 rounds down the barrel. 40 in the first outing and 120 today. The only cleaning on this barrel took place after the 40 rounds with a bore guide, Parker jag and Hoppes 9. Patched until it came out clean. I boresnaked the 308 and that’s it.

I didn’t check my “group size” when I started today. I shot one at 100 and 5 at 200 which resulted in a small gray blob with the white paint being taken off, good enough for me.

I am leaning towards the 6.5 ammo being very slow.. and try some 6.5 precision hunter. But is there anything else I should look at?

Thank you

 

[Supersubes]

Something is wrong for sure. Borrow a chronograph, and do a tall target test on the scopes.

My 16” 6.5x47 with the 140 ELD’s outperforms both of your rifles, and that makes no sense.

 

[Northernjets]

Something can't be right here. I have a 26" 1:8 running 140 eld-m reloads @ 2818 fps. My dope for 640m/700yds is 4.4 mils. For your numbers, my loads would have to be dragging ass at only 2337.5 fps mv. Very slow would be an understatement at those speeds...

 

[acudaowner]

why choose get both own both yea choices .

 

[BradleyH]

Something can't be right here. I have a 26" 1:8 running 140 eld-m reloads @ 2818 fps. My dope for 640m/700yds is 4.4 mils. For your numbers, my loads would have to be dragging ass at only 2337.5 fps mv. Very slow would be an understatement at those speeds..

I agree! I felt like it was somewhere around 2300. Buying factory is easier and a time saver for me but I may need to get another set of dies

 

[BradleyH]

Something is wrong for sure. Borrow a chronograph, and do a tall target test on the scopes.

My 16” 6.5x47 with the 140 ELD’s outperforms both of your rifles, and that makes no sense.

I was able to get a few boxes of precision hunters tonight, I’ll give them a try tomorrow and hopefully it’s night/day difference

 

[DocRDS]

fyI my cold weather dope for 1000 140g 6.5 ELD-M is 9.2 (1000 DA, 28F) out of a factory AT-X. Warm weather dope is about 8.6 (86F/ 4000 DA) Sumtins up with the Creedmoor dope.

500+ all seem low compared to mine while your 100-400 almost lines up at 500+ things go very amiss. It goes 0.5 dif, 1 diff, 2 diff, 2 diff.
We had a bunch of manbuns in Franks class, and all had very similar data--even the 130 gr "speedy" was only about 0.5 mils different at longer ranges. Hopefully some context to help troubleshoot. Velocity at 1000 should be around 1350 fps and my measured MV is ~2730 for Hornady ELM-M

Yours Mine
100 - Zero 0
200 - .5 0.4
300 - 1 1.1
400 - 2 1.9
500 - 3.3 2.8
600 - 5.2 3.9
700 - 6.9 5
800 - 8.1 6.2

 

[BradleyH]

fyI my cold weather dope for 1000 140g 6.5 ELD-M is 9.2 (1000 DA, 28F) out of a factory AT-X. Warm weather dope is about 8.6 (86F/ 4000 DA) Sumtins up with the Creedmoor dope.

500+ all seem low compared to mine while your 100-400 almost lines up at 500+ things go very amiss. It goes 0.5 dif, 1 diff, 2 diff, 2 diff.
We had a bunch of manbuns in Franks class, and all had very similar data--even the 130 gr "speedy" was only about 0.5 mils different at longer ranges. Hopefully some context to help troubleshoot. Velocity at 1000 should be around 1350 fps and my measured MV is ~2730 for Hornady ELM-M

Yours Mine
100 - Zero 0
200 - .5 0.4
300 - 1 1.1
400 - 2 1.9
500 - 3.3 2.8
600 - 5.2 3.9
700 - 6.9 5
800 - 8.1 6.2

Were you running factory ammo or reloads for your dope? I’m about to follow @Supersubes advice and grab a chrono.

 

[DocRDS]

That was factory Hornady ammo. And doped using weaponized marh to boot

 

[RG0099]

Your 6.5 math is off. If you do the weaponized math correctly you will see a consistent increase up to 900 yards +/-, not a almost 2.0 mil increase in a 100 yards. Your problem is in your 500 to 600 numbers. It should be no more then 1.0-1.2 mils different, and more in the 1.0 range.

 

[spife7980]

I’m purposefully running 140s slow at 2600 and my 800 elevation is 7 mils

You are even slower still by a good margin.

A chrono is super useful.

If it’s accurate though maybe leave well enough alone

 

[BradleyH]

I was able to get my hands on some factory 6.5 143 ELD-X for a range trip this morning. It was actually slightly faster but something still seems off.

The following is the delta in the dope from the 140 ELDM above and ELDX.

100 - zero
200 - (-0.1)
300 - (-0.1)
400 - (-0.1)
500 - (-0.4)
600 - (-0.3)
700 - (-0.5)
800 - (-0.4)

I could be off by a tenth either way but the ELD -X’s were faster.

For example the 700 yard dope for the ELD - X was 6.4 vs 6.9 on the ELD - M.

But I’m unsure if it’s the ammo.. maybe the barrel, or operator error?

Next up on the list is a Chrono, different brand of ammo, and reverify ranges on targets 600 + ( maybe my set of targets 600, 700, 800, 900 are actually much further hence why my dope really deviates after 600).

 

[DocRDS]

Have you tall tested your scope?

With that data, something is very off.

Shoot at 100, dial 10 mils. See if it tracks

 

[BradleyH]

Have you tall tested your scope?

With that data, something is very off.

Shoot at 100, dial 10 mils. See if it tracks

I have not but I will make an effort to test tomorrow. It’s a Mark 5 if that makes a difference

 

[BradleyH]

Well I want to thank everyone for the possible solutions to my problem, however I am an idiot.

I took my 7mm-08 to the range to see how it did vs the 6.5 dope. But I did remember batteries for my rangefinder.

Low and behold the 600 yard target was 700, 700 was 800, etc.

I was going from 500 to 700 and not knowing it.

Purely my fault

 

[TheOE800]

Weaponized math doesn’t lie!