Hello All,
Just got back from the range with my first attempt at an Optimal Charge Weight test on my new 6.5x55 Swede!
Specs:
Remington 700 LA, blueprinted
24" Bartlein Med Palma 1:8 twist (round count = 40 at beginning of test)
Berger 140 Hybrid
2.473 coal to ogive (0.010" jump)
New Hornady Brass - necks chamfered, flash holes deburred, necks bumped back to 1.760" for good fit.
All shots at 100 yd, with front rest and rear sand bag.
Wind gusting up to 25mph, going from 8 o'clock to 2 o'clock.
I tried two powders: IMR 4831 and IMR 4350. I had a little better luck with the 4350...
I added some calculations from QuickLoad in there for comparison, and highlighted where I thought the nodes might be. I saw not signs of pressure, so I may work it up a bit hotter to see where it goes. What do y'all think about the nodes I highlighted? I guess my next steps are to fine tune the powder charge a bit more and play with seating depths. What have others used for hybrids? 0.020" + jump?
Interesting that the barrel times almost match for the node 45.8gr 4381 and 43.6gr 4350... maybe gives some credence to the optimal barrel timing concept.
Just got back from the range with my first attempt at an Optimal Charge Weight test on my new 6.5x55 Swede!
Specs:
Remington 700 LA, blueprinted
24" Bartlein Med Palma 1:8 twist (round count = 40 at beginning of test)
Berger 140 Hybrid
2.473 coal to ogive (0.010" jump)
New Hornady Brass - necks chamfered, flash holes deburred, necks bumped back to 1.760" for good fit.
All shots at 100 yd, with front rest and rear sand bag.
Wind gusting up to 25mph, going from 8 o'clock to 2 o'clock.
I tried two powders: IMR 4831 and IMR 4350. I had a little better luck with the 4350...
I added some calculations from QuickLoad in there for comparison, and highlighted where I thought the nodes might be. I saw not signs of pressure, so I may work it up a bit hotter to see where it goes. What do y'all think about the nodes I highlighted? I guess my next steps are to fine tune the powder charge a bit more and play with seating depths. What have others used for hybrids? 0.020" + jump?
Interesting that the barrel times almost match for the node 45.8gr 4381 and 43.6gr 4350... maybe gives some credence to the optimal barrel timing concept.
