03-13-2018, 04:44 PM
BluntForceTrauma Wrote:I think your 18" barrel is key here.
If Sierra's reloading data shows 2750 fps as the fastest speed for the 107 TMK in a 24" barrel (loading PPV and TAC), and if one loses about 25 fps per barrel inch, then we'd expect an 18" to get 2600 fps with that bullet. Right?
So, if your 29.0 XBR load averages 2580 fps from your 18", you're in the ballpark.
Yeah thats what Im figuring out too. I dont think Im even close to shooting out my 18 Grendel barrel yet but the thought of snagging a 20 or 22 for that extra little bit of speed is temping. Accuracy and mobility trumps speed to a certain extent for me. Ill see what a decide to do after my next build takes off.

