I have for years been a user of H335 for 223 with 55 gr. Hornady SP and FMJ.

I am starting to reload 308  using bullets in the range of 150 to 170 gr.

I am looking for one powder that would work well for the 223 and 308.

Would RL-15 be a good choice?

Thanks for your time and help.

I use 're15 for heavy bullets in 223 and it works great.  Haven't tried it with 55 grain, but Lee 2nd has data.

It might be a little on the slow side for 55s. Honestly if you want the best results you probably need to pick up

a few powders.  H4895 works great with 55grn 223, and light bullets in 30-06, so that might work for you.

You can also try 8208xbr, CFE223, there are quite a few that work with both rounds. Experiment!

RE-15 is an excellent option for one powder in both .223 and .308. Others include:

H4895
VihtaVuori N140
Varget

and IMR-8208-XBR when used with lighter bullets (<168 grains) in .308.

There's a bunch of powders that can work for your purposes.
Hodgdon Benchmark is one of my favorites and should work very well.
I haven't used BLC-2 with 55s, but they worked well with 62s and it works good with those weights in .308.
Tac also works pretty good with your choices.
I haven't used it in .308 but even H-335 has data.
The list goes on and on...

I have had very good results with RL15 in .223 77gr SMKs and .308 178gr AMAX. For heavy match bullets i prefer RL15. Norma 203B is also very good and CFE223 does well with the heavier bullets. For the lighter bullets, i use CFE223.

I loved H335 in my .30-06 years ago but had a factory load (Federal Premium) that shot sub MOA and I had no time for reloading.  Fast forward to more recent times, I have a heavy barrel .308 that absolutely loves RL-15.  I will not even think about another load for that gun.  I started my oldest (now 15) daughter out on the same .30-06 using 125 gr Hornady SST/Nosler BT's and Accubonds (hunting) and used RL15 starting load - accurate, low recoil, kills deer very well.

As has been stated RL-15 does meter good for an extruded powder and pretty well overall IMO.  If "pretty well" is a PITA for you, you might want to look at ball powders again.

Now for the .223...  I will be following close as I have and like H335, BLC-2, etc, - but not loving anything so I too am looking to limit the powders and see what can happen with .223 and RL15.

rl15 were garbage groups with 55gr .223 for me. YMMV

8208 XBR has proven to be excellent for 55gr .223, not sure it'll push the bigger caliber you want but if so, you really should give it a try.

RL15 works very well with 168-175 SMK in my .308. Its my rifles preferred powder

RL15 has worked for me down to 52gr, and you should find a combo with the 55's.  It really shines for.308 so no problems there for sure.

Now it's finding R15 that's the problem. I bought a WOA 1x8 upper and R15 was said to be a preferred powder w/SMK 77.
I couldn't find any for months until finally at a GS a couple of weeks ago and I had to pay $29/lb. Hopefully you'll have better luck finding it.

My most accurate loads for both .223 and .308 use Reloader 15.

I use H4895 for 69+ 223 loads 308 and my 30-06 Garand loads


If you are looking for a ball powder try TAC or AA2520