hello. i need some help finding a good load for the 223.i have a 1:8 twist barrel. this is my first foray into small caliber semi auto shooting.i dont expect to break any records but if i can get a load working it could be interesting.
Ehh.... I've not used my gas gun for that far (16" V-Match carbine), but it really depends on what you realistically expect. Personally, I'd say 500yds is a bit optimistic for a .223 on game, even small stuff like prairie dogs. But to each their own.
A couple loads that I've came across over time that work really well (all were suggested for others, so I'd say they all work pretty well for others, but reduce your starting charges anyway, YMMV) are about any 50-52gr bullet, and 27.7gr of Win748, 25.5gr of H335, or 26 or so grains of Viht N133. I don't remember how many grains, but Ramshot Xterminator is excellent also. I believe Ramshot Tac and Viht N540 work well w/ the heavier bullets. One that I've heard of recently and am curious about is, curiously enough, called '10x' Can't remember who makes it though. Think it was Alliant. Supposed to be excellent in .223, .22BR, etc. size cases. Hodgdon Benchmark is highly recommended, as is Varget (minor PITA as it is not a ball powder, w/ that small of a case).
In summary, a good cheap load would be Speer 50gr TNTs (about $75-80 per 1000, last time I checked), Win748, H335, or Xterminator. Win748 works, but shoots a little dirty. Xterminator works well, and shoots clean and is in my experience, extremely temperature stable.
I have shot quite a few Rockchucks using a Colt Heavy Match Flat top, 20" 1X9" barrel. The load was the 60gr. Hornaday V-Max with 26 grs. W748, Rem. brass, CCI small mag. rifle primer. This combo provided 3/4" groups and stayed in the center of a 500 meter sighter gong with no flyers. Hits on rockchuck were impressive until ranges exceeded 250 yards,then they seemed to run out of steam. I used standard dies and a Lee crimp die very lightly, and the loads functioned perfectly. The neat thing of that kind of set-up is that you can usally launch a Chuck with one shot, and hit it again in mid-air!
In my Service Rifle, for 600 yard shooting, I load 24.5 grs of Varget behind an 80 gr Sierra MatchKing. At 200 & 300, same load pushing a 69 gr SMK.
The 69's can be made to fit the mag, but the 80's are loaded long, and used as single shot only. If you need repeat shot capability, forget the 80's, as you'll use up too much powder space if you seat them deep.
Depending on your needs, those are two great loads.