For what it's worth....shot some 175 GMM over the weekend to compare. Rifle is a Howa 1500 with 20" barrel. 2539 fps, 9 SD, 27 ES for a 5 shot group that was .75"
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For what it's worth....shot some 175 GMM over the weekend to compare. Rifle is a Howa 1500 with 20" barrel. 2539 fps, 9 SD, 27 ES for a 5 shot group that was .75"
Just got my box from Brownells with two boxes of FGGM 168 match ammo and a box of 168 SMKs to do some load matching.
First things first was I measured the CBTO of the FGGM and found it varied between 2.226 and 2.230 on the several samples I checked and an OAL of 2.800 plus or minus a few thou. I did not check all 40.
Next I set up a dummy cartridge using my FF brass drilled and tapped 6/32 and a 168 SMK from my new shipment loaded and found touch at 2.220 which means in my Shilen match barrel the FGGM is .006 to .010 IN the lands. No wonder is shoots so well!
To confirm, I slid a live FGGM round up the chamber with the bolt out and gave it a firm push. With a cleaning rod down the muzzle, it took a firm push on the rod to dislodge the round confirming the factory load is in the lands in my barrel.
Since I'm developing this load for 300 and under, I'm considering finding a lower and more accurate node. Maybe somewhere around 38 or 39 grains. Any comments on where to start or where that node might be?
26 inch, 10 twist Shilen, 205M's, Varget, Hornaday match brass.
Edit: I pulled down a new FGGM 168 Sierra Match today and to my surprise it had 40.0 grs of "special" powder. I expected to find 42.0 grs IMR 4064 but i guess they don't use that any more. Listed velocity is still 2650 fps.