6-284 /107SMK/Ramshot Magnum-Results
I built up a 6-284 on a Savage target action and installed a 28" Shilen prefit barrel, put those in a Bell and Carlson Medalist stock(sorry no pics yet)
For load workups I loaded at the range with a load giving me 3250fps with the 107smk's,57gr Ramshot Magnum, and did a seating depth test. I used this velocity because I read it was a very accurate range for this cartridge.
After finding the best seating depth I did pressure workups.
I shot at each charge through the chrono until I reached 3450fps,61.5gr Ramshot Magnum , and still without any high pressure signs, but figured that was enough velocity.
I then worked backwards and shot loads of 2 more each through the chrono and watched for good ES. At the 3400 range, 60.5gr Ramshot Magnum I had a load that read 3392,3400,3395 fps.
Looked good to me so I loaded 3 more up and shot them at 565yds.
I also shot 3 rounds of 57gr to compare.
For the 57gr load, which by the way shot 3 shots into .25 at 100yds, shot a 5inch vertical at 565yds, with es being about 40fps.
Proving again that you need to shoot at long range to really see what a load does! Of course we all know that!
For the 60.5gr load:
Vertical was about 2 inches total, with 2 of the three shots being within one inch
I shot 12 more shots, for four -3shot groups.
The vertical was never more than 2 inches, and horizontal not more than 3 inches. A couple groups were 1.5"
As a note:
It seems like these charges are very high, but I noticed no difficult bolt lift, the Fed 210 primers all looked good, and the case web measured the same at 55grains -61.5grains., with no difference in expansion.
When I went back to reload the brass the primer pockets were still snug. I am using Lapua 6.5-284 brass necked down.
I was shooting in 95 degree heat with 90 percent humidity. Typical central FL summer.
Looks like a great load for my antelope hunt in a few of weeks.
The 6-284 with the 107smk's at 3400fps, looks awesome in the charts and has 1000ft.lbs energy at 800yds+/-. In fact not many rounds can stay with it as far as drop and drift.
Just will have to see how the 107 smk's perform on antelope!
Anyone with any exprerience with them please chime in.
Last edited by RockZ; 08-28-2010 at 11:26 AM.