Starting roughly 10 years ago when the Grendel was a pretty hot article. Then Nosler came out with the 6.5mm 130 RDF in late 2017. With the 123 Scenar, an AR15 in 6.5 Grendel was transonic out to right at 1,000 yds at sea level, assuming you could get 2620 fps out of a 24" barrel. Some could ge close to the speed with 24's , but they just would not shoot. On the Grendel forum , people would just losing their collective minds trying to get it to shoot.
The 130 RDF if it you could make it work, was a game changer. A 123 Scenar has a G7 bc of .263, a 130 RDF .307. It was a beautiful thing,
Except for a shooter here or there, people just could not get it to shoot. It would send out 2" groups ot all day. So then they came out with 6 ARC, which was basically David Tubs 6mm AR. Everyone was ripe for the shift. The 6mm AR was simple to make as well, just using a type s sizing die with a .269 bushing. Most importantly, the 6 mm ARC made the rifle a real 1,000 yd platform. In a 6 ARC shooting ELD M 108 bullets a 24" barrel could get you 2,750 fps.. That would get you transonic to 1,100 yds wit 351 ft lbs. Hornady saw the benefits of the 6mmmAR, and they pushed the shoulder back several thousandths and then said " Look, a new cartridge a 6mm ARC". Any hoot, then the call came for everyone to bow to the 6mm ARC gGod.
However I was not buying it. A 130 RDF, with the right barrel and load could reach 2,600 f0s and maybe a little more from a 24"" barrel. Pretty hot load, trashing your brass, but attainable.
When you compared the 6mm ARC to a hypothetical 130 gr RDF Grendel, it just did not make much sense. the Grendel holds its owne (?actually better than ARC at 1,000 yds 1.93 mils vs 2.18 mills for the ARC. The Grendel is just not as fast⁰ a round, so you have more drop at any given distance, but that is a constant factor. Gravity does not change. Wind to target does. A 130 RDF at 2650 fps will be transonic at sea level to 1,175 yds. At 1,000 yds, sea level, a 130 gr RDF round retains 558 ft lbs , the 6mm ARC 108 ELD M retains only 421 ft lbs. Drop and drift at 1,000 yds Grendel 8.9 mills drop, 1.93 mils drift (10 mph crosswind) The 6mm ARC 9.03 mils drop 2.52 mills drift. If you go to a 6mm 115 RDF adjusting the speed f9r bullet weight the ARC produces 8.72 mills drop and 2.16 mills drift.
So the trick for the Grendel is getting the 130 RDF to shoot. So best velocities are from the Black Hole Weaponry P3 barrels. So last year bought a 24" 264 LBC BHW barrel. Never got it to range, so I started looking at the problems, and it appeared to me the problem is the magazine restriction is 2.3 to 2.29 in ACS mags and less in others. The closer I can get to the lands, I would think would give better results. 130 RDF In the 264 LBC a 130 RDF hits lands at 2.375.
So to get as close as possible, the answers a windowed mag. PRI make a modified windowed 10 rnd 6.8 magazine. I just recently got this mag and decided to see just how close I could get. To feed properly, I had to file the on Notch in the magwell a couple of kits ands wider. Also, the barrel extension just I trades into the magwell so I filled the extension flush with mag well. So now the rifle cycle rounds without getting hung on the extension lip in magwell. The max COAL now is 2.373. So I am thinking of running some loads 2.37 at .005 of lands.. If anything is going to , this will. At 2.370 I should maximize room in boiler room and dam near be kissing the lands.
If this fails, there is the130mgr Berger Hybrid OTM tactical .287 G7 bc. At the same speeds at sea level, 9.92 mils drop , 2.21 mills drift. So while it does not beat the 115 gr RDF ARC , it's close. There is also the 140 gr RDF option. At 2,486 fps the 140 RDF produces 9.87 mils drop 1.93 drift and its transonic to 1,125 yds. A lot more energy as well, with 565 ft lbs at 1,000. Either way, I plan on getting some loads out soon and establishing some base line data.
Any of these will produce more recoil, but my 24" with scope is in the 13 lb range. So I won't notice it.
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The 130 RDF if it you could make it work, was a game changer. A 123 Scenar has a G7 bc of .263, a 130 RDF .307. It was a beautiful thing,
Except for a shooter here or there, people just could not get it to shoot. It would send out 2" groups ot all day. So then they came out with 6 ARC, which was basically David Tubs 6mm AR. Everyone was ripe for the shift. The 6mm AR was simple to make as well, just using a type s sizing die with a .269 bushing. Most importantly, the 6 mm ARC made the rifle a real 1,000 yd platform. In a 6 ARC shooting ELD M 108 bullets a 24" barrel could get you 2,750 fps.. That would get you transonic to 1,100 yds wit 351 ft lbs. Hornady saw the benefits of the 6mmmAR, and they pushed the shoulder back several thousandths and then said " Look, a new cartridge a 6mm ARC". Any hoot, then the call came for everyone to bow to the 6mm ARC gGod.
However I was not buying it. A 130 RDF, with the right barrel and load could reach 2,600 f0s and maybe a little more from a 24"" barrel. Pretty hot load, trashing your brass, but attainable.
When you compared the 6mm ARC to a hypothetical 130 gr RDF Grendel, it just did not make much sense. the Grendel holds its owne (?actually better than ARC at 1,000 yds 1.93 mils vs 2.18 mills for the ARC. The Grendel is just not as fast⁰ a round, so you have more drop at any given distance, but that is a constant factor. Gravity does not change. Wind to target does. A 130 RDF at 2650 fps will be transonic at sea level to 1,175 yds. At 1,000 yds, sea level, a 130 gr RDF round retains 558 ft lbs , the 6mm ARC 108 ELD M retains only 421 ft lbs. Drop and drift at 1,000 yds Grendel 8.9 mills drop, 1.93 mils drift (10 mph crosswind) The 6mm ARC 9.03 mils drop 2.52 mills drift. If you go to a 6mm 115 RDF adjusting the speed f9r bullet weight the ARC produces 8.72 mills drop and 2.16 mills drift.
So the trick for the Grendel is getting the 130 RDF to shoot. So best velocities are from the Black Hole Weaponry P3 barrels. So last year bought a 24" 264 LBC BHW barrel. Never got it to range, so I started looking at the problems, and it appeared to me the problem is the magazine restriction is 2.3 to 2.29 in ACS mags and less in others. The closer I can get to the lands, I would think would give better results. 130 RDF In the 264 LBC a 130 RDF hits lands at 2.375.
So to get as close as possible, the answers a windowed mag. PRI make a modified windowed 10 rnd 6.8 magazine. I just recently got this mag and decided to see just how close I could get. To feed properly, I had to file the on Notch in the magwell a couple of kits ands wider. Also, the barrel extension just I trades into the magwell so I filled the extension flush with mag well. So now the rifle cycle rounds without getting hung on the extension lip in magwell. The max COAL now is 2.373. So I am thinking of running some loads 2.37 at .005 of lands.. If anything is going to , this will. At 2.370 I should maximize room in boiler room and dam near be kissing the lands.
If this fails, there is the130mgr Berger Hybrid OTM tactical .287 G7 bc. At the same speeds at sea level, 9.92 mils drop , 2.21 mills drift. So while it does not beat the 115 gr RDF ARC , it's close. There is also the 140 gr RDF option. At 2,486 fps the 140 RDF produces 9.87 mils drop 1.93 drift and its transonic to 1,125 yds. A lot more energy as well, with 565 ft lbs at 1,000. Either way, I plan on getting some loads out soon and establishing some base line data.
Any of these will produce more recoil, but my 24" with scope is in the 13 lb range. So I won't notice it.
Sent from my SM-T970 using Tapatalk