Home Forums Hunting & Shooting Ask The Gunwriters reduced loads with TAC

Also, ALL spherical powders are double-based, meaning they have added nitroglycerin, which also affects burn-rate compared to single-based extruded powders. (Not all extruded powders are single-based, but many are.)

Consequently, spherical powders usually burn less consistently and completely in reduced loads. This was one of the early "problems" with TAC. When loaded to pressures around 60,000 PSI it burned VERY cleanly, which was unusual for spherical rifle powders at the time. But even with "starting" loads, say around 55,000 PSI, it didn't burn as consistently or as cleanly. Consequently quite a few handloaders tried it, and when starting loads left visible powder-fouling in the bore, and often didn't shoot very accurately, they didn't even try maximum loads.

Don't know how many handloaders contacted me about this, basically whining that it didn't burn cleanly or result in very good accuracy, but it was quite a few. I advised them to add more powder--and all reported fine results.

What all of this comes down to is that just because TAC has a similar burn-rate to IMR4895, it doesn't act anything like 4895 with reduced charges.

That's been my experience as well, but a LOT of hunters apparently aren't concerned about temperature-sensitivity because it doesn't vary all that widely in their area. I have generally found that just about ANY modern smokeless powder won't vary much in pressure/velocity at temperatures from about 20-85 Fahrenheit.

But I happen to live and hunt in Montana, which has the widest range of recorded temperatures of any of the 50 United States, from -70 to +117--which is why I tend to prefer temp-resistant powders. I suspect Ontario has a pretty wide range as well!