Have a model 21 cooper in 223. After using 748 and trying 322 went to benchmark. With 25.7
and 25.8 grains I can get 1/4" groups. I am just starting for took forever it seems.
748 was ok at 27 grns. The 322 was just frustrating and I never found a target load at
all. 24 grns was ok for coyotes.
Have not Chrono the benchmark yet, but will asap.

What bullet and how many grains...Maddog

I am shooting 50 grn. Blitzkings.

Slay, I shoot a Cooper 21 in 223. The load that I use is 26.4 grains of AA2230 powder a Federal 205M primer, and a 52 grain bullet. I have used Sierra 52 grain MKs and the shoot very accurate, but for varmints I like the 52 grain HART HP benchrest bullet. On groundhogs it is a killer! Killed a loarge ground hog at 394-yards last year. It was late in the season and he was beyond plump with fat for the winter. He took two hits. in all I killet 52 ground hogs last season with the Cooper and the load mentioned. How accurate is the load in my Cooper you ask? At 100-yards from the benchrest I can hit 22 cal bullet holes. At 200 yards the load will group under half inch if I do my job behind the rifle. The AA2230 powder is truly a pleasure to load. Once my Harrell is set to throw 26.4 grains I just drop the charges in the cases. Thay very from charge to charge less then 1/2 of a 10th of a grain.

Slay, in my cooper I have very very good accuracy with benchmark, good side benefit is the velocities are great also. With 52 HPBTM Sierra and 26.5 gr of benchmark I get 3450 fps and with 27.3 gr benchmark and 40 vmax's I get 3660. Accuracy is less than 1/2" Great shooting rifle and one of my favorites

i have had great luck with varget, 26.0 grains with a 50 grain VMAX.

how does benchmark compare? faster burn? slower?

-Matt

From what I have read it's slightly faster. Great velocity
and realy cracks out there for me. Have shot 3/8" a few times now. Like shooting a 22 poa and poi right on centre.