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Howa mini-action in grendel to be released in mid-2016
I can wait till mine is actually built. I want a HMA30602KHC. That should be their shortest ( 20 barrel) lightest (5.7lb) Grendel with Kryptic camo. I can do my own scope.
Fantastic! So that would be either the HMA90622KHC Highlander or the Yote KMA90622YOTE I believe. I gotta find a source. I think Eastern Outfitters deals with Ya'll.
I read on another thread here on the forum that the twist rate on the prototypes is 1:9. I strongly recommend 1:8 for the 6.5 Grendel.
If you go to Berger Bullet's Twist Rate Calculator and enter in data for a sort of worst-case scenario — 6.5mm 130 Berger AR Hybrid at 2450 fps at temperature 0 and altitude 0 with a 1:8 twist — you get a "comfortable" stability factor of 1.61. Good article on this by Litz here.
Changing only the twist rate to 1:9, you get "marginal" stability of 1.27.
To get back to comfortable stability with a 1:9 in those conditions — let's say you're on the Alaskan coast in winter — you'd need a muzzle velocity of 4,000 fps!
Howa: Please, change the twist on your 6.5 Grendel mini-actions from 1:9 to 1:8 before these go into production!
P.S. If you're trying to be efficient by using the same barrels as your 6.5x55s, they, too, will benefit going to 1:8.
P.P.S. Bryan Litz tested velocity loss from twist rate increase and found it averaged only 1.33 fps per inch of twist rate. So if your 1:9 shoots 2601.33, then your 1:8 will shoot 2600 fps.
:: 6.5 GRENDEL Deer and Targets :: 6mmARC Targets and Varmints and Deer :: 22 ARC Varmints and Targets
Sounds good. Well pass this along.
From my personal experience... And I'll upload pictures tomorrow... I shot nothing but sub 1" three shot groups at 100yards with factory Hornady superformance sst 123gr rounds. Wind was around 10-12mph. I managed to keep the 20" HB to .800" center to center and the 22" std bbl to .720" with the 1-9 twist.
I read on another thread here on the forum that the twist rate on the prototypes is 1:9. I strongly recommend 1:8 for the 6.5 Grendel.
+1
My 20" 1:9 twist J&T keyholes 127LRX's at 100, and shoots the 140SGK's with mediocre accuracy. If I were to buy another AR grendel barrel, it would definitely be a 1:8 twist. I'd still be seriously interested in a 1:9 Micro, but even more so a 1:8 :-)
My 20" 1:9 twist J&T keyholes 127LRX's at 100, and shoots the 140SGK's with mediocre accuracy. If I were to buy another AR grendel barrel, it would definitely be a 1:8 twist. I'd still be seriously interested in a 1:9 Micro, but even more so a 1:8 :-)
I have personally shot all three models, and achieved sub 1" groups with factory Hornady ammo. This from a 20" rifle with a 3-9 power scope. I really don't think you'd have to ever worry about keyholing @100 with this setup.
GSPH, right on! There are a lot of us here just dying for something like this.
Doing it right the first time with a 1:8 will just compound the success, as glowing accuracy reports start coming in from all ranges, bullets, and conditions.
According to Litz, having a less-than-optimal BC doesn't necessarily affect accuracy at 100 yards, only that it "means, in practical terms, that your bullets drop more quickly and deflect more in the wind."
:: 6.5 GRENDEL Deer and Targets :: 6mmARC Targets and Varmints and Deer :: 22 ARC Varmints and Targets
I have personally shot all three models, and achieved sub 1" groups with factory Hornady ammo. This from a 20" rifle with a 3-9 power scope. I really don't think you'd have to ever worry about keyholing @100 with this setup.
Matt, the same rifle that keyholes 2 out 5 Barnes 127gn LRX's will average 5 123gn sst's into 1.25" with nice round holes :-)
Glad to see these rifles on the way. One configuration that I think would be $ is a youth model, there is not a better youth cartridge IMO than the Grendel, rifle can be light weight, accurate, smaller sized and still not recoil while being effective further than most should be shooting.
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