02-27-2018, 09:32 AM
VASCAR2 Wrote:Another difference is Hornady 9th addition manual for the 6.5 Grendel is a 14.5” barrel that is pin and welded to 16”. I think the 10th edition Hornady uses an 18” AR-15 barrel but I don’t own that manual. Speer and Sierra use a universal receiver with 24” test barrel for obtaining their data. Speer nor Sierra list their pressures for maximum charges, I’m curious if their data actually test lower than 50,000 PSI. Western powders list the pressure for each powder bullet combination and use a 20” 6.5 Grendel barrel.
All these differences in manuals makes it difficult to predict how each individual barrel will perform with data listed in loading manuals. After testing reloads in my AR-15 6.5 Grendels I’ve observed trends but I test each new powder and bullet by loading low and gradually working up. With the high ballistic coefficient of .264/6.5 bullets I rarely load maximum charges especially with ball powders that are sensitive to high temperatures.
Wasn't that the Hornady 8 that's 14.5 pinned to 16? My 9th edition says it's an 18" barrel for Grendel... but you're right in the differences betw all the mfr books. Add to that any differences in rifle frictions as well...
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