6.5 Grendel Chronograph results

[VASCAR2]

A Friend and I conducted a chronograph test today with our 6.5 Grendel AR-15's and a Magneto Speed Chronograph. The temperature was 76 degrees, overcast skies, Barometric Pressure 30.05, Humidity 78 %, Dew Point 68 Degrees at 350' ASL. We shot at paper targets set at approximately 110 yards.

The first 6.5 Grendel was a 16" chrome moly 1:9 twist J & T Distributing CAR gas system with a Double Star lower, Double Star 6 position collapsable stock with a RRA LPK and RRA NM trigger. A E O Tech 512 mounted for the test.

First hand load to test chronograph, 85 grain Sierra Varmint JHP, 29.0 grains X-Terminator, S/B large rifle primer fire formed mixed 7.62X39 brass.

1. 2718
2. 2712
3. 2682
4. 2700
5. 2771
6. 2718
7. 2703
8. 2706
9. 2690
10 2696


Max 2771
Min. 2682
Avg. 2709
S-D 24.4

120 grain HP BT PPU lot # 23 15 02

1. 2409
2. 2397
3. 2383
4. 2391
5. 2380

Max 2409
Min 2380
Avg 2392
S-D 11.6

110 grain FMJ PPU lot # 19 1501

1. 2501
2. 2499
3. 2527
4. 2516
5. 2507

Max 2527
Min 2499
Avg 2510
S-D 11.5

123 grain A-Max Hornady lot # 3110140

1. 2415
2. 2430
3. 2401
4. 2418
5. 2431

Max 2431
Min 2401
Avg 2419
S-D 12.2

123 Grain SST Hornady lot # 3140701

1. 2441
2. 2445
3. 2433
4. 2416
5. 2437

Max 2441
Min 2416
Avg 2430
S-D 10

Hand load 123 grain Nosler CC 31.0 grains CFE 223, CCI 450, Hornady cases.

1. 2448
2. 2444
3. 2446
4. 2448
5. 2460

Max 2460
Min 2444
Avg 2449
S-D 6.2

100 grain FMJ Wolf steel case lot # 23 IP 01 2015-01

1. 2515
2. 2499
3. 2486
4. 2509
5. 2528

Max 2528
Min 2486
Avg 2507
S-D 15.9

The next 6.5 Grendel we tested was a 18" Brownell's Liberty 1:8 twist stainless Steel barrel mid length gas system, RRA railed hand guard with Vortex 4-16 Viper PST, RRA NM trigger and RRA 6 position stock.

Photo of 18" 6.5 Grendel with Magneto Speed Chronograph attached.



120 grain HP BT PPU

1. 2460
2. 2443
3. 2459
4. 2444
5. 2470

Max 2470
Min 2443
Avg 2455
S-D 11.4

110 grain FMJ PPU

1. 2544
2. 2580
3. 2550
4. 2585
5. 2591

Max 2591
Min 2544
Avg 2570
S-D 21.4

123 grain A-Max Hornady

1. 2467
2. 2451
3. 2488
4. 2453
5. 2461

Max 2488
Min 2451
Avg 2464
S-D 14.8

123 Grain SST Hornady

1. 2493
2. 2489
3. 2490
4. 2491
5. 2502

Max 2502
Min 2489
Avg 2493
S-D 5.1

Hand Load 123 grain Nosler CC 31.0 CFE 223, CCI 450, Hornady cases.

1. 2459
2. 2469
3. 2479
4. 2484
5. 2468

Max 2484
Min 2459
Avg 2471
S-D 9.8

100 grain FMJ Wolf

1. 2583
2. 2576
3. 2575
4. 2567
5. 2555

Max 2583
Min 2555
Avg 2571
S-D 10.6

We next tested a 20" Shilen 1:9 twist SS barrel, Vortex Viper 6.5-20X50 scope, PSA upper and lower, Hogue free float tube, RRA NM LPK with PSA 6 position stock.

120 grain HP BT PPU

1. 2488
2. 2478
3. 2486
4. 2467
5. 2483

Max 2488
Min 2467
Avg 2480
S-D 8.3

110 grain FMJ PPU

1. 2611
2. 2609
3. 2617
4. 2627
5. 2612

Max 2623
Min 2609
Avg 2614
S-D 5.6

123 grain A-Max Hornady

1. 2497
2. 2505
3. 2514
4. 2510
5. 2500

Max 2514
Min 2497
Avg 2505
S-D 6.9

123 grain SST Hornady

1. 2521
2. 2503
3. 2506
4. 2504
5. 2522

Max 2522
Min 2503
Ave 2511
S-D 9.4

123 grain Hand Load Nosler CC 31.0 CFE 223, CCI 450 AA cases.

1. 2534
2. 2521
3. 2532
4. 2529
5. 2518

Max 2534
Min 2518
Avg 2526
S-D 7.0

100 grain FMJ Wolf Steel Cased

1. 2625
2. 2622
3. 2620
4. 2608
5. 2602

Max 2625
Min 2602
Avg 2615
S-D 9.8

107 grain Hand Load SMK, 28.5 IMR8208XBR CCI 41 Hornady cases.

1. 2650
2. 2664
3. 2666
4. 2665
5. 2648

Max 2666
Min 2648
Avg 2658
S-D 8.8

The last rifle we tested was a 24" Alexander Arms 1:9 twist 6.5 Grendel chrome moly barrel with Millet scope.

Here is a photo of my shooting partner with the 24" AA 6.5 Grendel with the Magneto speed chronograph attached.

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120 grain HP BT PPU

1. 2546
2. 2558
3. 2584
4. 2554
5. 2553

Max 2584
Min 2546
Avg 2559
S-D 14.6

110 Grain FMJ PPU

1. 2700
2. 2680
3. 2681
4. 2678
5. 2680

Max 2700
Min 2678
Avg 2683
S-D 9.1

123 Grain A-Max Hornady

1. 2574
2. 2563
3. 2580
4. 2557
5. 2570

Max 2580
Min 2557
Avg 2568
S-D 9

123 Grain SST Hornady

1. 2587
2. 2582
3. 2575
4. 2590
Only 4 shots

Max 2590
Min 2575
Avg 2583
S-D 6.5

123 Grain Hand Load Nosler CC 31.0 Grains CFE 223, CCI 450, Hornady cases.

1. 2623
2. 2608
3. 2624
4. 2622
5. 2618

Max 2624
Min 2608
Avg 2619
S-D 6.5

100 grain FMJ Wolf Steel Cased.

1. 2691
2. 2684
3. 2697
4. 2701
5. 2702

Max 2702
Min 2684
Avg 2695
S-D 7.4

107 Grain Hand Load SMK 28.5 IMR8208XBR, CCI 41, Hornady Cases.

1. 2745
2. 2737
3. 2717
4. 2707
5. 2739

Max 2745
Min 2707
Avg 2729
S-D 16.1


123 Grain Hand Load, Nosler CC, 28.5 Accurate 2520

1. 2531
2. 2543
3. 2542
4. 2487
5. 2552
6. 2549
7. 2544
8. 2557
9. 2541
10 2555

Max 2557
Min 2487
Avg 2540
S-D 20.1

[VASCAR2]

Here is a list of the tested ammo by average velocity for each barrel length.

120 Grain HP BT PPU

16" 2392

18" 2455

20" 2480

24" 2559

110 grain FMJ PPU

16" 2510

18" 2570

20" 2614

24" 2683

123 grain A-Max Hornady

16" 2419

18" 2464

20" 2505

24" 2568

123 Grain SST Hornady

16" 2430

18" 2493

20" 2511

24" 2583

Hand Load 123 Grain Nosler CC, 31.0 grains CFE223, CCI 41

16" 2449

18" 2471

20" 2526

24" 2619

100 Grain FMJ Wolf

16" 2507

18" 2571

20" 2615

24" 2695

Hand Load 107 Grain SMK 28.5 IMR8208XBR, CCI 41 Hornady cases.

20" 2658

24" 2729

[VASCAR2]

I have used optical chronographs for many years but this was my first time using the Magneto Speed chronograph. I was really impressed by this chronograph. We had varied weather throughout the day including overcast skies, light rain then clear sunny skies. It would have been very difficult to accomplish this chronograph session using an optical chronograph.

I was really surprised that the attached Magneto Speed sensor did not affect the accuracy of the rifles. We were not trying to shoot to get good groups but trying to get a base line for different ammo velocities from a variety of barrel lengths. My Son in Law has a 22" LW 6.5 CSS and if I get the opportunity I'll add the velocities from his barrel.

Here is a picture of the group from the 123 grain Nosler CC out of the 20" Shilen.



Here is a typical group for the 110grain FMJ PPU Brass factory ammo.



Here is a group from the Shilen with 123 Grain SST.



Here is a photo of a group fired from the 20" Shilen with the 120 Grain HP BT PPU round.

[wheelguner]

Thanks for sharing your data and the effort you put into it.

[VASCAR2]

I wasn't able to attach a photo to the previous post of a group from the 20" Shilen with the 100 grain Wolf FMJ steel cased ammo.

[PA_Allen]

Excellent and well reported data set. Thanks for taking the time to do this.
- PA

[JASmith]

...I was really surprised that the attached Magneto Speed sensor did not affect the accuracy of therifle...

My experience with the Magnetospeed is similar to yours.

The added weight, however, WILL affect your point of impact and MAY affect accuracy.

The strap needs to be tight or the unit will drift between shots. The change in mass location will cause the impact point to shift, making one think the accuracy is not so good.

I have seen the unit fall off of the muzzle during sready shooting runs. The velocity readings tend to get screwy just before that happens. The approach to embarassment is frequently overlooked because of concentration on shooting, fatigue, etc. Best to verify strap tightness every five rounds until one gets a feel for how many shots can be done before checking again. I have gone as many as Forty with no problem, but have had the thing come loose in as few as ren, depending on how well I tightened the strap.

Also, the muzzle wants to be at or behind the curved blast section. That will protect your sensors and also avoid another source of error in velocity readings.

[am4966]

Thanks for the info Vascar

[WIshooter]

Good pics and report

[rothirsch]

Great info. Thanks for sharing

[ah1whiskey]

that just the info i was looking for --cool--

[VASCAR2]

that just the info i was looking for --cool--

When I was contemplating buying a 6.5 Grendel in 2009 I only found data for the different barrel lengths on Alexander Arms web site which was reloading data. With several different factory ammo options available I thought this might be helpful. I could have shot one of my last two boxes of Black Hills loaded Les Baer 264 LBC 123 grain SMK ammo but I was to tite to burn it up. I have two boxes of Wolf 120 grain MPT that were early lots that I chose to save. I haven't bought any ammo loaded by Alexander Arms or Precision Fierarms to add to the list but others might contribute their data.

[LRRPF52]

That's really comprehensive and an excellent set of data.

[sneaky one]

V2- thanks for all that data, well done.

One thing to change is-move the Magnetospeed ahead about an inch or so, we have 1 here, it makes a difference where it's mounted - to end of bbl.

Should be end - in the center of the dip built into it, so the first transponder doesn't get too much powder blast upon it. Check it. Tryin to help is all. We like these compared to a chrono.

[VASCAR2]

Thanks foe the tip sneaky. The Magnetospeed actually belongs to a forum member so I'll pass the info along. I feel pretty lucky, I have two good Friend's that enjoy shooting the 6.5 Grendel.