Personally, I haven't tried T7 in any of Savage's. I have shot Pyrodex serverla years ago. The main reason I haven't shot Pyrodex in several years and T7 at all, is smokeless is legal here in NC, and ther just hasn't been any need to shot it much at all.
Herre is some of the better loads I tried with Pyrodex back in 1999 and 2000. These laods were shot out of the original 10ML, not the 10ML-II.
THREE 50 GRAIN PYRODEX PELLETS
250 gr Hornady .452 XTP 1,955 FPS 2,125 FPE
300 gr Hornady .452 XTP 1,908 FPS 2,430 FPE
PYRODEX “RS” SELECT
100 gr 250 gr Hornady .452 XTP 1,620 FPS 1,455 FPE
100 gr 300 gr Hornady .452 XTP 1,555 FPS 1,605 FPE
120 gr 250 gr Hornady .452 XTP 1,694 FPS 1,587 FPE
120 gr 300 gr Hornady .452 XTP 1,615 FPS 1,740 FPE
PYRODEX “P”
100 gr 250 gr Hornady .452 XTP 1,678 FPS 1,562 FPE
100 gr 300 gr Hornady .452 XTP 1,593 FPS 1,695 FPE
120 gr 250 gr Hornady .452 XTP 1,729 FPS 1,660 FPE
120 gr 300 gr Hornady .452 XTP 1,630 FPS 1,770 FPE
150 gr 250 gr Hornady .452 XTP 1,870 FPS 1,940 FPE
150 gr 300 gr Hornady .452 XTP 1,784 FPS 2,250 FPE
170 gr 250 gr Hornady .452 XTP 1,973 FPS 2,162 FPE
170 gr 300 gr Hornady .452 XTP 1,849 FPS 2,280 FPE
What Getonit said about plastic fouling is true. If your loads are hot and/or your bore is a little on the rough side, plastic fouling can build up and accuracy goes away. If the loads are litle hot, then you need to scrub the bore like Getonit stated. If your bore is on the rough side, then you may want to consider lapping the bore J-B Bore Cleaning compound. J-B compound is more of a cleaner, very very fine abrasive compound, that will more polish the bore than actually lap it. You don't need to fire lap it or anything that drastic. Just saturate the bore good, appy some J-B to a tight fitting patch, run that patch up and down the bore about 25 passes, re-satuate the bore, re-apply J-B to another patch, run it up and down the bore. Do this for about for about 200 passes. This will polish and smooth out the bore, reduce the fouling effect, and in most cases increase accuracy. This is expecially true on S/S 10ML-II's, as the button rifling process that Savage uses, causes fine razor burs on the edge of the lands of the rifling.