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Sorry Dusty, I wasn’t very clear at all.
I am under the impression that LT30, LT-32, and 2015 are all fairly similar like n-130, n133, and n135. Maybe I’m wrong?
CW
Yes, they are all three very similar. The story is somewhat convoluted, but the short version goes like this...
During the sixties, Dupont developed a powder, originally intended (but never used) for use in the then-new M16/5.56. They called the powder 8208 (not the same as Hodgdon's 8208). After awhile, with no apparent use for the powder, they declared it surplus.
Thunderbird purchased three lots of this powder.
Thinking it might be useful in benchrest cartridges, Thunderbird contacted Walt Berger. He tested the three lots, and really liked one of them. He bought the entire lot. That lot was sold as the now rather famous T-32.
As that lot of T-32 began to dry up, discussions were had with Hodgdon and Western Powder about recreating it. Western approached the Canadian facility which had created the original lot for Dupont. A deal was reached and that's how LT-32 came to be. LT-32 was (and presumably still is) made on the same machinery and has the same geometry as A2015. Its deterrent coating is slightly different, and according to Keith Anderson, Western's chief ballistician at the time, A2015 is about 10% slower than LT-32.
Recognizing that LT-32 was just a little bit too slow for cartridges like .30 BR, a few years later Western introduced LT-30, a "slightly faster" powder than LT-32, again by adjusting the deterrent coating. How much faster? I've never seen anything that specs the exact difference, but it appears to me to be on the order of 5-6%.
One other interesting detail with LT-32 and LT-30 (and presumably A2015, as well, though I've not seen it explicitly stated for that powder) is that those powders are supposedly held to a stricter 5% lot-to-lot burning rate variation than the more typical 15% seen in the industry.