grayfox Wrote:How does this string compare with say 123's and CFE or AR Comp, or XBR in your howa? I say this just to get a feel for how the barrel performs. Once you start getting above 2510-50 or so in a 20" for this weight class, IMO you're approaching or exceeding max. Just an opinion though.
I had some 123's going 2510-20 with CFE out of a 20" HB, and some 120 PH up about 2550, likewise for 120 gold dots... approx's because I don't have that rifle any more.
Anyway, nice test.
One more thing, is that a reversal about 30.0 or 30.6, where MV drops like that -- that can also be a sign you're getting to a max.
Did any of the loads feel compressed?
I like graphing results too...
I mostly shoot lighter, hunting bullets out of the Grendel bolt guns, 90-100 grns up to 120 Gold Dots. I have shot the 123 BTHP out of the Howa before but very little. I cant the find the data but it would have mostly likely been with TAC and I dont recall the speeds. I generally only use 8208 with lighter bullets, say with 107s and less. Almost no experience with AR-Comp, still have nearly a full pound of it left. Have used plenty of CFE 223 but again cant put my hands on any data, I find it dirty and very temperature sensitive. I tried PP 2000 MR w/120 Gold Dots looking for more speed and both times, I never got close to what Speer claims they did. Like - 200+ FPS less, both tests. Love their bullets but not their data. Had some other issues with their data and other calibers, the 6.5x55 Swede to be specific. Anyway, think Im going to try the Gold Dots next with this powder.
I agree, when you see the MV drops like that, and the see-sawing, its trying to tell you something.
And no, the loads werent overly compressed, if any. Well up into the shoulder but dont remember any intrusion into the neck. And I didnt need to use a drop tube or have to vibrate the cases. I remember thinking that was going to be an issue because Western Powders shows their 29.6 grn max load as compressed and this went 2 grns above that. Different cases though. I dont think I even had to adjust the seating die there at the end to keep all of COAL in spec.
A little spoiler alert! I feel it performed better, much better with 130 grn GameChangers. Typically dont shoot that heavy a bullet out of the Grendels anymore. If I feel the need, I just shove them in the Creedmoor. I tried them here because that weight bullet fell right in the middle of the Shooters World data. And Im glad I did! Shot 3 shot groups and it was extremely well behaved with nice predictable, reasonable increases in speed. Along with very reasonably ES/SD. The max charge of 31.0 grns averaged 2525 FPS with 13 ES/6.6 SD. Of course that was only 3 shots too. Looking forward to trying them again in the CZ this time. Its got a little more mag room to play with and 4 more inches of barrel. Could get interesting.