McGowen Precision AR-15 6-ARC build
#18
In my view it is not a case of exceeding hornady's pressures, since we don't know them. It is a case of exceeding hornady's MVs. I've done a graph of load vs MV for a few 6Arc loads now, for the data presented on here, and they all have shown, for a given powder charge, 140-180 ft/s faster MV than hornady's barrel at a given grs of powder, and that is taking into account the differing barrel lengths. This would not indicate to me higher pressures, however I can't totally explain it either.
If hornady, and I say, IF, they would publish their pressures, maybe we could figure it out better. For now I'm ok with the case fill, MVs and data I've been seeing in our 18-20" barrels.
For some reason these barrels in hand are showing to be faster than whatever hornady is shooting.

Another thought, for a suitable powder speed/burn rate, there is no reason (that I know of) not to expect a 100-gr bullet to get somewhere in vicinity of 2700 ft/s, since in the 6.5 you can do that -- I have done it with the 100 Nosler and 100 ttsx and 100 eldm in my 20" Grendel Lilja and in the Grendel-BA barrel I have. I know the 6 is slimmer, and the case a bit shorter, but in terms of energy imparted from a powder burn and acceleration, the two calibers should be "close" together for similar -mass bullets. To me that is just a physics thing.
Hornady doesn't show anything like 2700 for 100 gr class bullets, 20" barrel.
Call me a Columbo-style ballistics guy......
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Messages In This Thread
RE: McGowen Precision AR-15 6-ARC build - by danm - 07-01-2020, 06:23 PM
RE: McGowen Precision AR-15 6-ARC build - by danm - 07-29-2020, 05:26 PM
RE: McGowen Precision AR-15 6-ARC build - by grayfox - 08-31-2020, 02:31 PM

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