Disclaimer: I'm personally intent on running my bolt action rifle at higher pressures than I would run an AR chambered for the Grendel. I'm posting for informational purposes only. Don't try this yourself.
Some Nosler 130 RDF 2nds showed up Friday and I made it to the range yesterday afternoon. I know you guys don't like Quickload around here, but I've had good luck getting it to predict what powders will produce what velocity at what pressure in the past. And a friend was willing to run a few predictions for the little Grendel. Based on what Quickload suggested from my guessing, I ran short ladders with Ramshot Big Game and H4895. Big Game is probably about the slowest burning powder that I can imagine potentially being useful in the Grendel and still being able to fit anywhere near enough in the case, and I've read from a trusted source that Ramshot's ball powders aren't supposed to be as finicky about temperature swings as other ball powders. H4895 is a classic Hodgdon Extreme powder that has provided very good velocity and excellent load densities for me in the past. Quickload thought that 33 grains of Big Game should produce a hair over 2600 fps at about 61K psi, so I decided to top out there and back down in .3 grain steps. Another simulation thought that 30 grains of H4895 should run 2580 at not quite 62K, so I called that my max and again backed off in .3 grain steps.
I can't stress this enough: don't trust that the listed charges will lead to listed pressure on Quickload simulations. If I didn't own a chronograph, I would personally consider Quickload useless. But I do trust that it's usually pretty close to matching powder/pressure/velocity, and I've had good success using it for reference in the past- especially in more traditional cartridges like the 30-06 or 7-08 and 338 WM, which are basically just a smaller and larger 30-06, respectively.
And finally, 5 shot strings are very basic and preliminary testing for me. It's more common than not to see velocities not climb in steady increments, and sometimes even drop instead of increase. This is due to statistical variation more than anything when testing such small sample sizes. If one shot is on the high end of its velocity range for that charge and the next shot is on the low end for the next higher charge's range, it's not uncommon to have overlap- especially when increasing in such small increments. I'm mostly looking to start at what I think should 100% be a safe level, confirm that it is safe, get a ballpark on velocity, and move up while watching for signs of too much pressure.
So, with all disclaimers I can think of mentioned, on to the results:
Big Game
31.8- 2385
32.1- 2442
32.4- 2424
32.7- 2460
33.0- 2520
H4895
28.8- 2544
29.1- 2569
29.4- 2583
29.7- 2619
30.0- 2619
All the brass on the Big Game loads looks great. Quickload thinks that my top end load was only 55,000 psi or so. 2520 fps is fine, but 33 grains came up to the neck/shoulder junction even after holding an electric razor to the case to try and settle the powder. The H4895 loads all showed at least the tiniest bit of ejector smear on the head. I'm not sure if they're really over pressure, but they might be. I think this pound of H4895 is a little fast burning for its range, and it's acted that way in the past as well. The top two charges had the slightest bit of heavy bolt lift, too. That's usually a pretty good sign of exceeding 65K psi.
I think I'm gonna go back to AR Comp and give that a try. Since I've run up to 29.8 grains of it behind a 123 with no pressure signs, I'll probably go up to somewhere in the 28.5-29 grain range here. I'll have to sit down and think about it some more and try to extrapolate from existing data and prior experience to my best ability. But I'm not sure when I'll be able to get back to the range, anyway. If AR Comp doesn't give me any better results than H4895, I'll probably buy another pound of H4895(I'm almost out) and give it a go and see how the brass holds up to repeated firings at 2550 fps or so.
Next up, I fired some 140 Berger Hybrids that I had already loaded up awhile back. This was with TAC and AR Comp, which I've already tried lower strings of.
TAC
28.4- 2339
28.6- 2376
28.8- 2368
29.0- 2380
29.2- 2406
ARC
27.2- 2411
27.4- 2393
27.6- 2419
27.8- 2433
28.0- 2442
I think TAC is out. The only rifle that seems to like this powder is my AR. Normally, initial strings will give me some idea of how the rifle is going to like the powder, and every initial string I've shot with TAC has been a schit group. Conversely, all 5 of the AR Comp loads grouped under an inch, and the brass looked great. Quickload projections have me guessing that these should all be in the general realm of 60-65K psi, which is top end. I'm going to pursue this combination further with the 55 bullets I have remaining. Unless, of course, the 5 more that I also have loaded up with H4895 to run over the chronograph just for my own data reference purposes somehow prove themselves better. Either way, a 140 hybrid at 2400 catches up to my existing load of the 123 Hornady at just over 2600 by 600 yards or so.
Some Nosler 130 RDF 2nds showed up Friday and I made it to the range yesterday afternoon. I know you guys don't like Quickload around here, but I've had good luck getting it to predict what powders will produce what velocity at what pressure in the past. And a friend was willing to run a few predictions for the little Grendel. Based on what Quickload suggested from my guessing, I ran short ladders with Ramshot Big Game and H4895. Big Game is probably about the slowest burning powder that I can imagine potentially being useful in the Grendel and still being able to fit anywhere near enough in the case, and I've read from a trusted source that Ramshot's ball powders aren't supposed to be as finicky about temperature swings as other ball powders. H4895 is a classic Hodgdon Extreme powder that has provided very good velocity and excellent load densities for me in the past. Quickload thought that 33 grains of Big Game should produce a hair over 2600 fps at about 61K psi, so I decided to top out there and back down in .3 grain steps. Another simulation thought that 30 grains of H4895 should run 2580 at not quite 62K, so I called that my max and again backed off in .3 grain steps.
I can't stress this enough: don't trust that the listed charges will lead to listed pressure on Quickload simulations. If I didn't own a chronograph, I would personally consider Quickload useless. But I do trust that it's usually pretty close to matching powder/pressure/velocity, and I've had good success using it for reference in the past- especially in more traditional cartridges like the 30-06 or 7-08 and 338 WM, which are basically just a smaller and larger 30-06, respectively.
And finally, 5 shot strings are very basic and preliminary testing for me. It's more common than not to see velocities not climb in steady increments, and sometimes even drop instead of increase. This is due to statistical variation more than anything when testing such small sample sizes. If one shot is on the high end of its velocity range for that charge and the next shot is on the low end for the next higher charge's range, it's not uncommon to have overlap- especially when increasing in such small increments. I'm mostly looking to start at what I think should 100% be a safe level, confirm that it is safe, get a ballpark on velocity, and move up while watching for signs of too much pressure.
So, with all disclaimers I can think of mentioned, on to the results:
Big Game
31.8- 2385
32.1- 2442
32.4- 2424
32.7- 2460
33.0- 2520
H4895
28.8- 2544
29.1- 2569
29.4- 2583
29.7- 2619
30.0- 2619
All the brass on the Big Game loads looks great. Quickload thinks that my top end load was only 55,000 psi or so. 2520 fps is fine, but 33 grains came up to the neck/shoulder junction even after holding an electric razor to the case to try and settle the powder. The H4895 loads all showed at least the tiniest bit of ejector smear on the head. I'm not sure if they're really over pressure, but they might be. I think this pound of H4895 is a little fast burning for its range, and it's acted that way in the past as well. The top two charges had the slightest bit of heavy bolt lift, too. That's usually a pretty good sign of exceeding 65K psi.
I think I'm gonna go back to AR Comp and give that a try. Since I've run up to 29.8 grains of it behind a 123 with no pressure signs, I'll probably go up to somewhere in the 28.5-29 grain range here. I'll have to sit down and think about it some more and try to extrapolate from existing data and prior experience to my best ability. But I'm not sure when I'll be able to get back to the range, anyway. If AR Comp doesn't give me any better results than H4895, I'll probably buy another pound of H4895(I'm almost out) and give it a go and see how the brass holds up to repeated firings at 2550 fps or so.
Next up, I fired some 140 Berger Hybrids that I had already loaded up awhile back. This was with TAC and AR Comp, which I've already tried lower strings of.
TAC
28.4- 2339
28.6- 2376
28.8- 2368
29.0- 2380
29.2- 2406
ARC
27.2- 2411
27.4- 2393
27.6- 2419
27.8- 2433
28.0- 2442
I think TAC is out. The only rifle that seems to like this powder is my AR. Normally, initial strings will give me some idea of how the rifle is going to like the powder, and every initial string I've shot with TAC has been a schit group. Conversely, all 5 of the AR Comp loads grouped under an inch, and the brass looked great. Quickload projections have me guessing that these should all be in the general realm of 60-65K psi, which is top end. I'm going to pursue this combination further with the 55 bullets I have remaining. Unless, of course, the 5 more that I also have loaded up with H4895 to run over the chronograph just for my own data reference purposes somehow prove themselves better. Either way, a 140 hybrid at 2400 catches up to my existing load of the 123 Hornady at just over 2600 by 600 yards or so.
Comment