Thread: Bullet Seating depth and pressure (6.5 Grendel)

Originally Posted by Tentman

Gidday Pete - I ran these loads in Quickload to see what it said . . . which is only an indication but sometimes helps to understand what is happening.

Q/L doesn't have ADI 8208 but it shows IMR 8208 XBR - and since all these are marketed by Hodgdon one might "assume" they are the same - but no guarantee.

At 27.7gn of IMR 8208 XBR you should be getting about 2530 fps from a 22" barrel (I'll recalculate it if you let me know the actual barrel length), and pressure at 2.25 COAL is indicated at 53,800 psi. At a COAL of 2.26 the pressure indicated is 53,300, so bugger all difference. The Leade design and free bore will also be a factor. Just to fully disclose, the SAMMI max pressure for the 6.5 gendel is 52,000 psi so your loads are already "up there" - at 28.5gns the pressure is indicated at over 58,000 psi

Thanks Tentman for doing that.
That's interesting since ADI list 28.5gr. max charge but for the Sierra 123gr. BTHP (not the 123 SST) it would be interesting to run with the Sierra bullet as well.
Were down to an 18 inch barrel and using Federal 205 small rifle primer / hornady brass if any of that makes difference.

Interesting that quickload theoretically shows higher pressure with a slightly deeper seating - I would assume (have read) thats because of case capacity being reduced ?
This is a common load and lots on here have had best results around the 28gr. or slightly over mark.