Rev. Mike. I hope this gives you what you want.
Well the weather forecast was for calm winds becoming light and variable in the afternoon. Yeah, sure. Got to the range and it was blowing 8 to 10 MHP easy. Temp was about 65* and the wind felt cold. I'm wearing a tee shirt and jeans.
I had ten sets of three rounds starting with 42.0 gr. with a half grain increase on up to 48.0 gr. Speer's max for the 160 gr. Hot Core is 44.0 gr. Before I go any further, this was in my rifle and nothing gave way. Results were if nothing else a bit on the weird side as will be explained. Sad to say these loads were tested in my FN Mauser and this M70 without my normal use of the chronograph as the last time I used it it gave very erratic readings. Just haven'y gotten down to sending it in for repair.
Load #1 Triangular group about 1.25x"3 5/8". Primer nice and round.
Load #2 Group is 1 1/16"x 1/16". No change in primers.
Load #3 Group 1 1/2' x 1/2" Primers round with slight cratering. (I should note that even the mild Winchester 145 gr. ammo shows mild cratering in this rifle.)
Load #4 Group 1 1/2"x 1 1/2" perfect triangle. Very slight flattening, no change in cratering and edges still nicely rounded.
Load #5 Group 1/4"x 1". Primer no different from load #4.
Load #6 Group 1"x 1 1/4" No change in primer flattening and no cratering.
Load #7 Group 13/16"x 3/8" Primers still with rounded edges and slight cratering.
Load #8 Group 3/8"x 1 3/8" Primers still have nicely rounded edges. slight cratering on one case only.
Load #9 group 3/8"x1/2" Primers slightly flatter than previous cases. Cratering definitely more noticeable but not much different than what I've seem in factory .270 Win. and .300 Mag loads.
Load #10 Group 2 5/8" x 2/3/8". Primers flattest so far with still slight rounding at the edges. Cratering quite noticable.
Rifle Winchester M70 FWT, brass brand new Remington, flash holes reamed, trimmed and primer pockets uniformed.
Wind out of the east 8 to 12 MPH estimated, temperature about 62 when starting and 66 when done.
Target was a black 2.5"x2.5" square with a 1.0" white square in the center. Odd number shots were on the lower left hand corner and even numbered shots on the upper right hand corner. No effort was made to bring the scope into line with point of aim as the rifle is sighted in for a good load with the 150 gr. Nosler PT.
Interesting thing is shots on the lower left corner always seemed to me much better than when the upper right corner was used as the aiming point. I've used those target for more than twenty years and this is the first time I can recall that happening. It's also interesting that the FN Mauser showed pressure at load # 5 vs load #7 or 8 depending on how you look at it in the M70.
All in all an enlightening day at the range.
Paul B.
