Going to give some 40 grain bullets a try in the .223 Rem. Thinking about the Hornady 40gr V-Max, but will need to get some powder - anyone have a place to start? Another question, do you need to shoot magnum primers with ball powder? Thanks.

Try Viht N120 and rem7 1/2. I'm getting over 4000fps with this combo in several rifles with excellent accuracy. Start with about 20 or 21 grains. I'v been useing 24 grains and can see hits to +/- 200 yards without a muzzle break. If your useing a good rest you will see hits beyond 250. This has been my favorite for over 10 years. Those 40grVmax really make PDs fly.

Try Benchmark and CCI 400 primers with 40 V-Max. This is my most accurate load in my 223. My record shows 0.295" for five shots at 100 yds and 0.837" for five shots at 200 yards.

This is with a Rem. 700 LVSF (22" barrel) velocity near 3700-3750. I was getting 4100 out of my 22-250 with the same bullet. 4000 in the 223 is really pushing it.

photo of the group at 200

I use Remington brass br400 primers 27.3 grains of TAC and 40 v-max molly. Shoots grate and the TAC powder is very clean burning. I am getting 3300 fps out of a 20" barrel.

Mine are strictly in bolt rifles...

My favorite 2 are..
with RL 7, I am able to hit 4000 fps, with a 40 grain Sierra HP..( some will accuse this load of being way too hot, but the number of firings I get per case reload, doesn't indicate that)

the second one, and the one I use the most... is with Blue Dot..

I have 2 of those...

14.5 grains with a 40 grain HP Sierra: 3375 fps ( 26 inch barrel) and it yields 500 rounds per pound of powder

10 grains of Blue Dot and 40 grain Sierra, 218 Bee equivalent ( 2800 fps)... use this as a walking varminter load in a sporter weight rifle...
what I love also, is besides both of these loads allowing me to see my hits in the scopes site picture, the 10 grain load, all I have to do is deprime and reprime the case.. it doesn't expand enough to need even re neck sizing to reseat a new bullet...with a mil dot scope it is still easily a 250 yd load...while yielding 700 rounds per pound of powder!

Centershot: Be sure to try this load: Nosler 40 gr. Ballistic Tips, Winchester brass, 24.5 grs. of AA 2015 and Federal 205M primers.
This is a lower velocity loading but splendidly accurate in two of my 223's.
Best of luck with your 223.
Hold into the wind
VarmintGuy

W-W brass
Rem. 7 1/2's
40 gr. Noslers, moly plated
27.5 gr. AA 2230 (bought 60 lbs @ $9.99 per lb, Midway sale)
3750 fps in 4 different 223's

Excellent, thanks guys - great info. I'll get some loaded up.