Another vote for 748...great with 50-55 grainers and also with Sierra's 69 gr BtMK for use out to 300 yards. And Re-15 is as good with 69's and 77's. Either is a MOA round for my Colt HBAR. Rod
That is good to know. I am mainly a fair weather paper puncher so I don't see the issues with temp and TAC but will keep that in mind the next .223/5.56 powder purchase.
A lot of matches have been won with temp sensitive powders like Re15 and IMR4895. The shooters would just adjust their sights to compensate for the change in velocity due to temperature. Even a 20 shot string isn't going to warm up the rifle fast enough to significantly change the bulk of the shots going downrange.
Even "temp stable" powders aren't truly stable, just much variation per degree of temperature. So anything under 1 fps/degree is temp stable in my book, and anything under 0.5 fps/degree is gravy. Most of my powders lie in between those two numbers, IMR4064 and PowerPro 2000MR lie in that range. But Varget and H4895 are under 0.5 fps/degree (at least with service rifle calibers).
Still, a lot of match winners are still using Re15.
