I have not had consistent results using 66-68 gr bullets with either LT30 or N130, in a 6ppc. Rather than go into a detailed show 'n tell, after several sessions with each it appears both powders have a very narrow "tune window." Even with a tuner they'd shoot the lights out on one target, and ten minutes later I couldn't hit my a$$ with both hands on the next!
Additionally they both acted "spikey," which is (state of) Maine-speak for quick to over-pressure. That showed up with hard bolt lift, flat primers, and chronograph readings that were all over Hell-and-back. I gave it up and stayed with my "goto" IMR 8208 load.
A season or two ago another poster had great luck with "LT31" in a 6PPC. As you might suspect, it was a mix of LT30 and LT32. Not one to poo-poo (as in ridicule, or dismiss - not a #2
), something without trying it, I bought a pound of each and had at it. Initial tests went well. Somewhere around 28.0 grains of a 50:50 mix gave about 3,380 ft/sec and no extraction problems, but the chronograph numbers weren't great. Less than 28 grs had worse numbers, and even a little more gave bolt click. On an IBS 100 yd score target in mild conditions, the load would just drive a couple for X's, and then throw the next one for a "hanger (down south called a "line-licker") 10! Another session with it about a week later gave the same results, so I threw in the towel on the effort.
Both of these powders appear to have identical sized grains. For the two cans I had the only difference I could see was the LT30 grains were shinier than the LT32 ones. For the mix I had put 2 weighed ounces of each in an empty 1 lb powder bottle, which was then swirled and tumbled around by hand for about 5 minutes. Now, sometime after abandoning the effort I wondered if the blend wasn't mixed well enough. I took a small sample and put it under a magnifier. Lo and behold (!) it was easy to pick out groups, or clumps, of shiny grains and dull ones. A-ha! Inconsistent results are being caused by a poor mix i.e., some rounds had more (or less) of one powder, than the other. Easy fix . . . just mix the mix, longer! So I did that several times, checking the progress with the magnifier after each 4-5 minutes twirl, shake, and tumble session. Contrary to my expectation that the mix would become better blended . . . it didn't! In fact it didn't seem to change at all. The grains of one or the other continued to group together. I gave up at that point. The only explanation I could come up with is maybe the deterrent coating was causing the grouping together effect, but who knows. I don't have a rotary tumbler, so I didn't try mixing it that way. Someone who does and wants to give it try can. If so, please let me know what happened.
Chris Mitchell
WD
