Denton, yes give us that load when you get back home. I am a convert to the 7x57 so I enjoy hearing people tell their stories.
Surprised Mule Deer or AussieGunwriter haven't chimed in yet.
JB and I have posted a lot over the years on this cartridge and the variances stated are real enough that every rifle owner needs to learn his own rifle. Coming from different hemispheres, John recommended walking away from some powder that recorded more temperature variation where that was never an issue for me where Winter is 40-60 degrees and with no hunting seasons or bag limits, we hunted and killed game until it got either too hot or there was too many snakes.
My latest 7x57 has the tightest chamber and shortest throat of the rifles I have owned or tested and also has a slower twist being a BACO Super Grade Model 70.
Although I have maybe a dozen or more different 7mm bullets on my shelves, the best 3 loads for this rifle uses:
175gn Partition over 46gn of Rel 17 for 2640fps. Several groups are slightly under or around half inch.
175gn Accubond over 48gn of Rel 22 generates slightly larger groups and 2645fps average velocity.
The 150gn Nosler BT is hugely underestimated in the 7x57 case where I have shot as tight as .194" groups with extreme spreads as little as 9fps. My best load todate uses 50gn of H 4350 for 2755fps.
The same 50 grains with the 150 grain Parition opens the groups slightly and still around MOA for 2765fps velocity averages.
In my Rigby .275, that rifle liked the 140gn Barnes X and TSX bullets but this new BACO, shoots best groups using 46gn of VARGET and 2820fps. This is a heavy charge for Varget but the rifle likes it.
The last recommendation I would offer is the 120gn TTSX which shoots very well in the BACO using 53gn of H 414 which was always the best performing powder in all my 7x57's over the last 35 years or so.
I used Winchester 120 Primer through the 80's and 90's, Federal 210's from the 90's until now and tried some CCI 200's recently, but my current rifle doesn't like them and opens the groups so I am staring with the Federals.
Because of the variations in these rifles, travel your own road and start a couple of grains down with any recommendation.
John
