RiverRider
Handloader
- Dec 9, 2008
- 1,489
- 176
A few months ago I swapped for an Interarms Mark X chambered in 6mm-284 wearing an older Bell & Carlson synthetic stock. It was fairly ugly, but the metal was in decent shape and the swap was very reasonable. With the rifle, I was given some handloads and the guy told me what he had been loading. I had no intention of firing his handloads or using his data or even the powder he had used, which I think was Re19. The first loads I tried were 95-grain Partitions over Ramshot Magnum. They shot okay, I was getting groups under an inch with hardly any effort at all but I noted velocity variations that were greater than I had hoped for. I was disappointed because Magnum meters so well.
Then the 90-grain Accubonds appeared. I stopped load development on the rifle and waited to get my hands on the ABs. I tried them with Magnum and I tried them with H4831SC. I saw much lower velocity spreads with the H4831SC, but with both powders my groups were still two inches and up. The exception was one 4831 load that produced a 0.88 inch group, but I did not pursue it because a half-grain of powder either way opened up to over two inches. That was the day I decided to abandon the AccuBond all together and go right back to the Partition.
Since H4831SC lowered the velocity variations I was seeing during my struggles with the AccuBond, I decided to give it a whirl with the 95-grain Partitions. I loaded up six charges of H4831SC and as the charge increased up to what I consider a maximum, groups tightened up to a little over half an inch. I then loaded a few rounds with this charge and varied seating depth a little and the sweet spot is very near the OAL I had been working with.
According to QuickLOAD, I should be at about 3220 fps @56,000 psi. I am actually getting about 3340 fps, and the corresponding pressure appears to be a little shy of 58,000 psi. Velocity variations are about 10 to 15 fps 98% of the time and I can live with that (with Magnum, 30 to 50 fps spreads within a three-shot group were pretty much the norm). Everything looks good at this level to me.
It's nice to have a rifle in a 6mm caliber that will actually shoot. Quite refreshing, actually, after going through SIX different rifles chambered in .243 Winchester that would not shoot MOA!
Then the 90-grain Accubonds appeared. I stopped load development on the rifle and waited to get my hands on the ABs. I tried them with Magnum and I tried them with H4831SC. I saw much lower velocity spreads with the H4831SC, but with both powders my groups were still two inches and up. The exception was one 4831 load that produced a 0.88 inch group, but I did not pursue it because a half-grain of powder either way opened up to over two inches. That was the day I decided to abandon the AccuBond all together and go right back to the Partition.
Since H4831SC lowered the velocity variations I was seeing during my struggles with the AccuBond, I decided to give it a whirl with the 95-grain Partitions. I loaded up six charges of H4831SC and as the charge increased up to what I consider a maximum, groups tightened up to a little over half an inch. I then loaded a few rounds with this charge and varied seating depth a little and the sweet spot is very near the OAL I had been working with.
According to QuickLOAD, I should be at about 3220 fps @56,000 psi. I am actually getting about 3340 fps, and the corresponding pressure appears to be a little shy of 58,000 psi. Velocity variations are about 10 to 15 fps 98% of the time and I can live with that (with Magnum, 30 to 50 fps spreads within a three-shot group were pretty much the norm). Everything looks good at this level to me.
It's nice to have a rifle in a 6mm caliber that will actually shoot. Quite refreshing, actually, after going through SIX different rifles chambered in .243 Winchester that would not shoot MOA!
:grin: Those 6mm's shoot! Nice job, and that's a screamer.
