Greetings,
I got to the range yesterday to do some testing and sighting in for some of the rifles for this seasons F class. I think I have posted before about selecting the 60 grain VMax for my 1 in 12" twist .223. BM8208 had been selected as it was a little faster and denser than AR2206H. The rifle, a VSSF will be used at 300 yards. Three sets of data were selected which could not have been more different.
For the 60 grain projectile Hodgdon listed a max of 23.6 grains for 3,057 fps, Hornady listed a max of 25.3 grains for 3,000 fps and Brian Pearce in his Pet Loads series listed a max of 25.4 grains for 3,148 fps. Not all that helpful. The quoted pressure for the Hodgdon load was only 51,700 PSI.
Anyway some test cartridges were loaded with 23.6 grains of BM8208, 60 grain VMax projectiles in S&B cases with Federal primers. These chronographed 2,950 fps or 100 fps less than the Hodgdons data in spite of the extra 2" of barrel and the much heavier case. This speed was a better match for the Pearce data. A load of 25 grains of AR2206H (1 grain under max) was also chronographed with the 60 grain in SBMC cases (average weight) which delivered 3,140 fps.
For comparison Hodgdon claimed 3,057 fps from 23.6 grain, Pearce claimed 2,911 fps from 23.5 grains and Hornady claimed 2,800 fps from 23.7 grains all of BM8202 (IMR8208XBR). Hodgdon and Pearce used Winchester and Hornady cases respectively and 24 and 22 inch barrels. Looks like something in the 24 to 25 grain range will be the goods so will keep you posted.
My Sendero 7mm SAUM also made the trip to the range for a rough sighting in with its new scope. Load testing continues.
Regards Grandpamac.
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