Post by dontek on Jun 20, 2018 11:39:57 GMT -8
I just wanted to post my (very limited) experience with the 6mm Hornady ELD-X 103gr out of my 24" 6x6.8 with IMR 8208 XBR, in case anyone else is looking at the feasibility of this bullet for this cartridge.
Here's some preliminary charge weight testing results (COAL 2.3"):
23.7gr SD: 13.7 AVG: 2516 FPS
1) 2527
2) 2527
3) 2514
4) 2498
24.0gr SD: 5.0 AVG: 2545 FPS
1) 2546
2) 2540
3) 2550
4) 2490 loose primer, dropped from results
24.3gr SD: 1.7 AVG: 2573 FPS
1) 2574
2) 2572
3) 2576
4) 2573
24.6gr SD: 24.7 AVG: 2600
1) 2605
2) 2631
3) 2596
4) 2571
I was just doing a quick workup to find where pressure signs began. I was not shooting for accuracy. Obviously, these nodes are small to take much stock in the SD.
None of these loads would lock the bolt back on an empty magazine; all were fired single-shot. I'm not sure why this is. All ejected okay. The lower in use this range-trip does have an ST-T2 buffer with a Sprinco Red Extra Power spring, however, my loads using the 70gr Varmageddon and same powder and lower locked the bolt back on every firing. Maybe these loads are a little light? Maybe I've got too much resistance in the buffer system? The intended, soon-to-be-complete lower for this rifle will have a standard rifle buffer and Sprinco Green spring; I'll report back if that makes any difference after the next range trip.
I got some very minor Case Head Swipes @ 24.3gr and above, however, this could be as much a timing issue as an overpressure sign, and the primers all look fine.
Anyway, judging by this quick test, I'm going to do some more testing with larger strings around the 24.3gr node and see if the very-low SD remains. Judging by the Hornady Ballistics Calculator, this load should be very close to Sierra 95gr TMK loadings in terms of energy, wind drift and drop; although, I'm not sure if the 4DOF calculator is accounting for lower BC at lower FPS for the ELD-X; I used .49 BC for the TMK based on Sierra's FPS statement.
These bullets extend WAY into the case, but, with the 8208 XBR, the fill rate is good and I could push a bit more without compressing.
I'm not sure what my intended use for this loading might be, but I was just curious if this long, heavy bullet could be of any use.
Here's some preliminary charge weight testing results (COAL 2.3"):
23.7gr SD: 13.7 AVG: 2516 FPS
1) 2527
2) 2527
3) 2514
4) 2498
24.0gr SD: 5.0 AVG: 2545 FPS
1) 2546
2) 2540
3) 2550
4) 2490 loose primer, dropped from results
24.3gr SD: 1.7 AVG: 2573 FPS
1) 2574
2) 2572
3) 2576
4) 2573
24.6gr SD: 24.7 AVG: 2600
1) 2605
2) 2631
3) 2596
4) 2571
I was just doing a quick workup to find where pressure signs began. I was not shooting for accuracy. Obviously, these nodes are small to take much stock in the SD.
None of these loads would lock the bolt back on an empty magazine; all were fired single-shot. I'm not sure why this is. All ejected okay. The lower in use this range-trip does have an ST-T2 buffer with a Sprinco Red Extra Power spring, however, my loads using the 70gr Varmageddon and same powder and lower locked the bolt back on every firing. Maybe these loads are a little light? Maybe I've got too much resistance in the buffer system? The intended, soon-to-be-complete lower for this rifle will have a standard rifle buffer and Sprinco Green spring; I'll report back if that makes any difference after the next range trip.
I got some very minor Case Head Swipes @ 24.3gr and above, however, this could be as much a timing issue as an overpressure sign, and the primers all look fine.
Anyway, judging by this quick test, I'm going to do some more testing with larger strings around the 24.3gr node and see if the very-low SD remains. Judging by the Hornady Ballistics Calculator, this load should be very close to Sierra 95gr TMK loadings in terms of energy, wind drift and drop; although, I'm not sure if the 4DOF calculator is accounting for lower BC at lower FPS for the ELD-X; I used .49 BC for the TMK based on Sierra's FPS statement.
These bullets extend WAY into the case, but, with the 8208 XBR, the fill rate is good and I could push a bit more without compressing.
I'm not sure what my intended use for this loading might be, but I was just curious if this long, heavy bullet could be of any use.
