Thanks to everyone that has shared their results and insight on this site. I’ve learned a lot from you guys! Here’s a small attempt to give back a little. There's not a lot out there on 6.5 Grendel cast.
Today I shot 11 different cast boolit test loads in my 6.5 Grendel AR at 100 yards. I’d done some testing prior with IMR 8208XBR and H335. The one load that had showed some promise was CCI-400, 22.0gr of IMR 8208XBR and the NOE 266-126-FN-A03 sized to .265” and powdercoated 2 times. BTW This mold is for the one with the smaller meplat- not the wide one that can be hollow-pointed. I’d heard the wider FN can have cycling problems in ARs. Some folks call this the “VonGruff” design. All rounds were fed from the magazine and there were no hiccups. Weather was 6 degrees Fahrenheit with a 5-15mph head wind at about 45 degrees. Not ideal conditions and I’ll say I didn’t “feel” like I was shooting well today but the results give me somewhere to work from.
Boolits were water-quenched clip-on wheel weights, sized and gas check installed to .265” with an NOE sizer, and then powder coated 2 times at 350 degrees (which may have taken some of the hardness back out of them). Nine loads were shot “as coated” and two were also shot with the boolits resized to .265” after PC. OAL was 2.125”. It’s a bit shorter than indicated by the radius leading into the nose but I was getting some point shaving when it was set longer. The lower charges (below max) help address the pressure change and this solved the nose shaving problem.
Best loads for me today were:
22.0gr IMR 8208XBR just over 1” for 4 shots (shot as coated)
25.0gr IMR 8208XBR 1 1/4” for 5 shots (shot as coated) (Quickload max= 27.2gr.)
26.0gr IMR 4895 1 1/8” for 5 shots (shot as coated) (Quickload max= 29.2gr.)
26.0gr IMR 3031 1 1/8” for 5 shots (resized to .265 after PC) (Quickload max= 27.5gr.)
A couple observations:
-The 22.0gr 8208 load shot a 3 ¼” “pattern” if the boolit was resized after coating but the 26.0gr 3031 load went from over 2” to 1 1/8” if the boolit was resized after. Weird. Perhaps some of our Gurus can share some insight on why this would be.
-The higher end loads (which are still well below maximum) shot well suggesting there may be additional headroom there. I’ll just have to watch for pressure signs and/or the rifle to start leading.
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Based on the Quickload chart, the 26.0gr IMR 3031 load should be up around 2300fps. This is definitely hunting velocity for this boolit and alloy. FWIW I have also cast softnose boolits with this mold and would probably use those to hunt.
I only chronographed one round today because my range isn’t set up for using a chronograph while shooting targets and I didn’t want to waste components chronographing loads that don’t shoot well. That round was 22.0gr of IMR 8208 XBR and it came in at 2005fps.
There you go. I hope this information helps others of the Grendel Horde!
Be safe!
John
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Originally Posted by Beaverhunter2
