fastest loading 223 55 grain?

steve garrett

Active member
what powder should yield the fastest speed loaded in 223 with a 55 grain bullet. The 223 is only rated at 55k psi, I want to load to nato spec of 62k at least. and yes I am shooting from a chamber that accepts nato rounds. bascially I am looking for a warm 223 load that gives me as much speed as I can get, then I will worry about if its accurate enough.
 
In my 26", 1-14 twist Hart, with minimal freebore
55g Nosler ballistic tips
IMI cases(tough)
CCI BR-4 or Remington 71/2 (tough primers)
26.0g of N135
very tiny groups
right at 3500 fps
No pressure issues other than cratered primers and I fixed that issue by sending the bolt to Greg Tannel of Gre-Tan rifles to get the firing pin bushed

I am not the only one that shoots this load, either.

This is a bolt gun load and you should work up to that load

things that increase pressure:
1-9 or tigher twist
going to a flat base bullet with more bearing surface and/or different bullet
Different lot of powder
different barrel that could be a tighter bore
Different brand of brass with less powder capacity than IMI

I have no problem shooting the above load in my rifle. In my 223 AI that has a 27" 1-12 twist, I shoot the 55g Noslers at 3650, bushed firing pin on that bolt also. These are real world velocities checked with an Ohler 35P that is two chronographs.

N133 with the 50g(3600fps) and N135 with the 55's are a world apart in accuracy and speed compared to probably the next best powder which would be toss up between H335 and Benchmark.

Be advised, work up in your rifle with caution, and if you have a 1-9 twist...all bets are off, that twist really jacks up the top end pressure on loads like this causing it to "spike" quicker. I had a 22 PPC, 223 AI, and 223 all with Hart SS bbls with mimimum SAAMI Match chambers with minimal freebore in 1-9 twists and they all caused pressure spikes quicker than the 1-12 and 1-14 twists with 50 and 55g Bullets.

What happens on the pressure spikes are as you would suspect, the bolt is very hard to open(Scuffed case head), cases with not so tight primer pockets blow the primers out(then you have to try and find the primer's anvil somewhere in your action along with the primer cup), not to mention the flyers.

So, work up your loads carefully, and take into consideration super hot weather if you shoot in that kind of weather(don't leave your ammo in the sun).

Good luck
 
N135 is the other I was going to say. I actually typed it out, then edited because I am not as familiar with it....
 
Originally Posted By: steve garrettwhat powder should yield the fastest speed loaded in 223 with a 55 grain bullet. The 223 is only rated at 55k psi, I want to load to nato spec of 62k at least.

As per quickload - loaded to 62,000 PSI and a 24" barrel, 55gr Hornady vmax :

Reloader 10x 23.4grs - 3371 fps
H4198 22.1grs - 3280 fps
H322 24.6grs - 3391 fps
Benchmark 24.9grs - 3300 fps
H335 26.0grs - 3380 fps
IMR 8208xbr 25.7grs - 3350 fps
CFE223 28.3grs - 3400 fps
 
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Western powders publishes 556 data, I actually just loaded up some 55gr NBT last night with tac to try

My load with 8208 and 55 nbt in my last barrel, although they shoot good in my new one as well, was 25.5gr. Of course you'd want to work to that first.
 
Originally Posted By: 2muchgunVarget ain't the answer.

AA2230 or N133 I'd say.

Most speed, less powder N133 may be most efficient of all.....

Agree with this. N133 was the fastest powder of all the powders I tried in the 223. Most accurate too with bullets 55gr and under.
 
Whats the hurry? I used to try for max speed, but accuracy was off most of the time, so I slowed down and I will take my accuracy anyday. (3/8" groups at 100 meters, with 55gr. V-Max with 25.5gr charge of H-4895 out of a RRA PP 20")
 
28.5 of target gets me 3650 in model 12savage 53 grain fb..
That was for Benchrest matchs 100 yards cover with a dime all day long
 
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