I used the same data that Remington Arms presented at the Small Arms Symposium on May 11, 2004 and added 6.5 Grendel to create a chart.
I had to interpolate the data for the 6.5 with a 16" Barrel - won't be able to update until I return to the US to do testing or one of you can provide me with test info for the Grendel from a 16" barrel.



This gives a great graphic representation of the high BC advantage.

See if you can get the ballistic data for the new 130gr bullets Arne's playing with. I'd be curious to see how they stack up.

Norma 130 VLD - .600 BC
Lapua 144 - .636 BC (Advertised) - .578 BC (Measured)
Lapua 108 - .480 BC
Lapua 123 - .542 BC
Lapua 139 - .615 BC
Sierra 107 - .470 BC
Sierra 120 - .420 BC

All BC's are G1 which is what bullet makers advertise. The above mentioned bullets are better represented by G5 or G7 profiles except the Sierra 120 which works well as G1.

OK, now is somebody could add some of the better BCs to the graph, I'd be a happy camper.

Arne
On the MK 107 Sierra only quotes a BC of .430 above 3350 Fps, .420 the next step down. So where did you get .470.
Also, i have shot alot (4 barrels worth the bulk of the rounds past 600) MK 142's and LAPUA 139's, these two bullets are twins BC wise as far as I can tell. Yet Sierra qoutes .585 tops for the 142, which agrees well with all the 1k shooting I have done with that bullet. So what makes you think the 139 is .615? Or are you just using published data till some measured data is available.
Especially when you recognize the 144 measured value is lower than the published #.
The 123 looks to be .510 if the 142 and 139 are really .585.
Those are all still very impressive, putting the 123 out of the mag toe to toe with the best available 175 out of a 7.62x51 in a gas gun platform.
Thus the "AR10 soul in AR15 body" BTW when is the t-shirt coming out????

The best .308 round out there is the Lost River Ballistic J40 bullet in 220 grains, with a BC of .930(!) No, I don't know what the actual BC is.

John,

Scott and Mid Tompkins ran the 6.5mm bullets and a bunch of 6mm ones downrange last March with chronos at muzzle and 600 yards. The two measured velocities were used to compute BC's and everything was corrected to Standard Conditions.

The Sierra 107 in 6.5mm was one of the bullets which fared better then advertised, the Lapua 144 fared worse (.578 vs.636) then advertised.

Of all the 6mm bullets, all of the 105-107 grain loads ranged in the .530's with the Berger producing less then advertised results.

When looking at the Lapua 139 and Sierra 142, they are so close in BC that they could be seen as twins downrange.

As far as the other BC's,

7.62 147 FMJ - .420
6.8 115 OTM - .340
5.56 77 HPBT - .362
5.56 62 FMJ - .283
7.62 123 FMJ - .256

It is very easy to see that the 6.8 115 OTM is not going to offer superior trajectory over the 5.56 77 OTM if launched at equal velocities. The only thing it will do is offer increased energy due to greater mass.

For more fun in 6.5mm

Lapua 100 OTM - .444
Lapua 108 OTM - .480
Lapua 123 OTM - .542
Norma 120 FMJ - .420
Norma 130 VLD - .600
Nosler 100 BT - .352
Hornady 95 VMAX - .365
Speer 90 TNT - .281

Anything official on the 120 Nosler BT? Thanks.

Thanks for the info on the origins of the data.
Of the 105-107 6's I would have to give the edge so far to 105 JLK.
Though I haven't shot any BERGERS. I have chroned the JLK's out to 300 and netted .520. 300 is about all I can manage by myself.
Good news on the 107 6.5's then, as I ordered a K to play with
I will make an effort to test both the MK 107 and LAP 123 at 300 for BC.

WARBUCKS I was only considering coventional lead cored, jacketed bullets, just to maintain a level field.

Nosler 120 BT - .458 BC

If you want to play with "what if's"

In my experience, 1 grain in bullet weight generally transulates into a velocity shift of 10 fps in the Grendel so a

123 Lapua @ 2700 fps = 108 Lapua @ 2850 fps = 144 Lapua = 2490 fps

120 BT @ 2650 fps = 100 BT @ 2850 fps

Arne,

Not to be anit picky, but if these are lead cored bullets, won't you run into problems selling to the military who now have an official "Green Bullet" policy that prohiits lead?

The green bullet policy is primarily for range use - havn't seen it emphasized lately.

With the exception of the very few programs that are concerned primarily with the mechanics of terminal ballistics the US military still has a very large emphasis placed on green ammunition especially at a procurement and logistics levels. To move forward in any study to a position where the military is serious about long term adoption one must at least demonstrate good compatability with such technology,

Is anyone able to create a graph showing comparative time of flight between these cartridges?

Oh and bullet drop trajectory too?

I'd also like to see similar ones done between the 108 grain, vs 120 vs 130 vs 144 grain loadings in Grendel too.

If you provide the data, I can do the graphs.