I would like to shoot some 105gr speer hot cores spitzers (not RN) from my 243 (26" 9twist) they have a pretty good BC and should be well matched for some white tail sized fallow.

243 data really does vary between manafacturers. Speer rate H4350 as the best but their charge weight is only 2gr below what is pretty stiff for an 85gr bullet in my rifle and I cannot believe that a slower powder would not do better.

I have some IMR 7828sc - does anyone have any data?

Check the IMR website:
http://www.imrpowder.com/data/rifle/243win-2005apr03.php

they list 44gr as max for the 105 AMax, velocity is 2894

Ya want velocity with decent accuracy with that bullet?

Try 44 grains of H 414, and a 105 grain Speer...

MV out of two Rugers with 22 inch barrels is 3250 fps...

Work up, but they have been reliable and no observed pressure signs in my rifles...

Nosler also listed 47 grains of IMR 7828 in one of their older manuals, # 3, and a 100 grain partition... the 105 Speer has been fine with that load data in my rifles also...

MV is listed at 3250 and that is what I got out of that combo also...

just work up to make the crybabies happy...

Adam:

IMR-7828 should be an excellent selection.

I have used 4831 original surplus powder exclusively in my .243's with all bullets of 80 grains or more for many years. This powder is slower than the currently produced 4831's, and I've found that in most applications it is only 1-1.5 grains faster than IMR-7828. In other words, what one will do, the other should also.

I would recommend you try IMR-7828 SSC if available. Its short grains allow it to meter smoothly and it packs more densely into the case, allowing a higher charge weight than regular 7828 (when appropriate).

Although I haven't tried the IMR-7828 in any of my .243's, I'm currently using it in a .25-06 where I'm liking it just a little better than the good old 4831. When my supply of 4831 is exhausted I'll likely switch most of its applications to 7828 SSC.

Try 46 grains of H1000. It works great with 105 A max in my .243.

The search still goes on but up to date 45.1 gr. of accurate data powder 86 pushes a 100 grain bullet over 3100fps and shows no obvious pressure indications. roger

43.0 grains of IMR 7828ssc pushes a 105 gr Berger at about 2960 fps from my rifle. I've pushed this bullet to 3100 with 44.6 grains of powder but accuracy was better at 43.
Still shoots minute of deer at 44.6 grains.