Long time lurker, first time poster. I built my first 6.5 Grendel last winter and fired it for the first time in late February. I had been skeptical of actual results versus the ‘hype’ but quickly found out my Investement was very sound and that I was far from disappointed. I’ll brag about my rig later, this one’s for load development. Not to be redundant, but I’ve had some interesting finds over the last week (all good).
The purpose of my build was long-range accuracy. I’d like to get respectable performance in the 800-1000 range just to see if I can do it. After reading these forums for months, last week I decided to start my very first workup. Since I’m going LR, I opted for the Berger 130 grain OTM AR Hybrid as one of my close friends has repeatedly had good luck with the Juggernauts in his 308. I chose powders based on both published load data and research from THIS SITE. To compare, I made two batches. One with BL-(c)2 and one with CFE 223. Here’s the result:
Barrel: 24” Satern cut bull barrel and matched bolt. 1:8.75 twist.
Conditions: 45 degrees farenheit. 1148 feet above mean sea level. Pressure: 30.01” hg
Target: 100 Yards. Chrony at 10 feet (measured).
All rounds seated to 2.260” (1.656” at 26 OGIVE with Bullet Comparator)
CCI BR-4 Primers for all rounds.
Brass is once-fired Hornady.
BLC workup: 28.3gr, 28.6gr, 28.9gr, 29.2gr. According to Hornady’s 10th edition, the limit for 129-130 class bullets in BLC is 29.5 grains - no need to try that on day 1. I loaded FIVE at each charge. Checked each one for pressure signs and shot across a chrony recording each shot.
28.3gr: 2241 FPS average, ES: 26fps. 1.1” center to center five shot group
28.6gr: 2259 FPS average, ES: 22fps. 0.9” center to center five shot group
28.9gr: 2299 FPS average, ES: 26fps. 0.5” center to center five shot group discarding a flyer (my bad!)
29.2gr: 2321 FPS average, ES: 28fps. 0.75” center to center five shot group
Not stellar. I’ve had better groups using the stock ‘Hornady BLack’ with 123 grain ELD-Match bullets. I’ve seen as little as 1/4 MOA out of that ammo, on one string.
On to CFE! This is going to mirror some info in the load data listed in the sticky on this section of the forum. CFE brought a tremendous improvement in velocity. It contradicts Hornady’s load data in the ‘10th edition’ manual which shows BLC having the velocity advantage for these weights of bullet. Yes, I know the OTM Berger is a different animal and each barrel varies. But I was pleasantly surprised with the velocity. For this run I started with 29.7 grain and incremented in 0.3 grain steps until I hit 31.2 grain. Max charge (per Hornady’s book) is 31.7 grain which seemed really high for this class of bullet.
29.7gr: 2419 FPS average, ES: 45fps. 1.2” group - not encouraging
30.0gr: 2450 FPS average, ES: 29fps. 0.8” group. Redemption is coming!
30.3gr: 2473 FPS average, ES: 39fps. 0.75” group. Coming into an Accuracy Node!
30.6gr: 2496 FPS average, ES: 50fps. Threw a flyer that opened the group to 1.5”, group was around 0.8”” without the flyer included.
30.9gr: 2532 FPS average, ES: 28fps. Small cloverleaf that had a center-to-center group of 0.3” from what I could measure! We have found a node for this barrel!
31.2gr: 2583 FPS average, ES: 59fps. Opened up into a small ‘box’ with 0.45” centers. Also had what I perceived as a tiny bit of flattening on the primers.
Phase 1 testing was fine. Phase 2 will be a Ladder test and I intend to do this at 300 yards.
The purpose of my build was long-range accuracy. I’d like to get respectable performance in the 800-1000 range just to see if I can do it. After reading these forums for months, last week I decided to start my very first workup. Since I’m going LR, I opted for the Berger 130 grain OTM AR Hybrid as one of my close friends has repeatedly had good luck with the Juggernauts in his 308. I chose powders based on both published load data and research from THIS SITE. To compare, I made two batches. One with BL-(c)2 and one with CFE 223. Here’s the result:
Barrel: 24” Satern cut bull barrel and matched bolt. 1:8.75 twist.
Conditions: 45 degrees farenheit. 1148 feet above mean sea level. Pressure: 30.01” hg
Target: 100 Yards. Chrony at 10 feet (measured).
All rounds seated to 2.260” (1.656” at 26 OGIVE with Bullet Comparator)
CCI BR-4 Primers for all rounds.
Brass is once-fired Hornady.
BLC workup: 28.3gr, 28.6gr, 28.9gr, 29.2gr. According to Hornady’s 10th edition, the limit for 129-130 class bullets in BLC is 29.5 grains - no need to try that on day 1. I loaded FIVE at each charge. Checked each one for pressure signs and shot across a chrony recording each shot.
28.3gr: 2241 FPS average, ES: 26fps. 1.1” center to center five shot group
28.6gr: 2259 FPS average, ES: 22fps. 0.9” center to center five shot group
28.9gr: 2299 FPS average, ES: 26fps. 0.5” center to center five shot group discarding a flyer (my bad!)
29.2gr: 2321 FPS average, ES: 28fps. 0.75” center to center five shot group
Not stellar. I’ve had better groups using the stock ‘Hornady BLack’ with 123 grain ELD-Match bullets. I’ve seen as little as 1/4 MOA out of that ammo, on one string.
On to CFE! This is going to mirror some info in the load data listed in the sticky on this section of the forum. CFE brought a tremendous improvement in velocity. It contradicts Hornady’s load data in the ‘10th edition’ manual which shows BLC having the velocity advantage for these weights of bullet. Yes, I know the OTM Berger is a different animal and each barrel varies. But I was pleasantly surprised with the velocity. For this run I started with 29.7 grain and incremented in 0.3 grain steps until I hit 31.2 grain. Max charge (per Hornady’s book) is 31.7 grain which seemed really high for this class of bullet.
29.7gr: 2419 FPS average, ES: 45fps. 1.2” group - not encouraging
30.0gr: 2450 FPS average, ES: 29fps. 0.8” group. Redemption is coming!
30.3gr: 2473 FPS average, ES: 39fps. 0.75” group. Coming into an Accuracy Node!
30.6gr: 2496 FPS average, ES: 50fps. Threw a flyer that opened the group to 1.5”, group was around 0.8”” without the flyer included.
30.9gr: 2532 FPS average, ES: 28fps. Small cloverleaf that had a center-to-center group of 0.3” from what I could measure! We have found a node for this barrel!
31.2gr: 2583 FPS average, ES: 59fps. Opened up into a small ‘box’ with 0.45” centers. Also had what I perceived as a tiny bit of flattening on the primers.
Phase 1 testing was fine. Phase 2 will be a Ladder test and I intend to do this at 300 yards.
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