Loading 223 with 77gr SMK and BLC(2)

[The Tiger]

Update post #13
Second update post #20

Still a loading novice. I've been at it a little while and had success with handgun loads. I never got around to loading rifle cartridges but now I'm motivated.

I'm going to load some 223 with 77gr Sierra Match Kings with the intent on going to some Highpower competitions as soon as I can get the ammo put together and my new scope zeroed.

I've sourced all the components, some are being shipped now.

Using BLC(2), CCI primer, Starline Brass

I have a Lee Turret press

Lee Book says between 23 - 24.9 grains with the BLC(2). BLC(2) was the second powder on the list under CFE223 which I can't find anywhere. Guy at the reloading store that sold me the powder said BLC(2) is very close to CFE in terms of burn rate.

Anyone want to give me a good place to start?

[TomReloaded]

Hodgdons site backs up that data, but it's 223 data... That means the 24.9gr max load is actually pretty light and still under 5.56... and it's very full in the case.

I'd toss in 24.5gr and go shoot, assuming this is an AR.

[The Tiger]

Hodgdons site backs up that data, but it's 223 data... That means the 24.9gr max load is actually pretty light and still under 5.56... and it's very full in the case.

I'd toss in 24.5gr and go shoot, assuming this is an AR.

Yes. AR with a wylde chamber

I see your point

[cz74]

OP, I have found the modeling software Gordon Reloading Tool helpful in my loading. If you are loading for precision competition, it is a useful tool. It gives you powder burn rate, ideal bullet travel, etc. for example per barrel length and twist rate you input. It is overwhelming at first, still lots to learn, but I have found it very interesting.

https://grtools.de/doku.php?id=en:doku:outputfields

[Rez805]

I came across this video when I was working with Tac.

11:55ish First shots.
16:30 Final results (5 shot avg velocity and standard deviation).
20:05 Brass and pressure signs at his max load.
22:05 group measurements.

https://www.youtube.com/watch?v=TeqZQT849Vs

Obviously every gun is different, work up, ymmv, etc., etc.

[smoothy8500]

load some 223 with 77gr Sierra Match Kings with the intent on going to some Highpower competitions

Generally the midrange 223 loads with 77gr work well at 600 yards. No need to recreate Mk262 or full strength 556 loads. Good luck and maybe I'll see you on the line.

[divingin]

OP, I have found the modeling software Gordon Reloading Tool helpful in my loading.

I found GRT to be a little wacky with CFE223. I don't recall specifics, but as I recall, their burn rate model seemed to be off. Not enough to cause me problems (I generally stay closer to midrange when working from data, and work up hot loads in the rifle) but something to be aware of nonetheless.

[BrassCase]

You can't go to light on the load or your AR won't function. If you have carbine length gas you can go a bit lighter and still get functionality, rifle length can be an issue on the lighter side loads so I tend to stay near max on my rifle length gas guns.

[QED]

For long range high precision loads I prefer the 77gr Sierra TMK over the plain SMK due to the former's better BC and external ballistics. IMR 8208 and varget yielded the best accuracy for me. Well sub MOA.

[QED]

Shilen select match barrel.

[ar15barrels]

This is NOT tested safe load data, but here is what Quickload thinks:

Cartridge          : .223 Rem.
Bullet             : .224, 77, Sierra HPBT MatchK 9377G G7
Useable Case Capaci: 24.058 grain H2O = 1.562 cm³
Cartridge O.A.L. L6: 2.260 inch = 57.40 mm
Barrel Length      : 20.0 inch = 508.0 mm
Powder             : Hodgdon BL-C2

Predicted data by increasing and decreasing the given charge,
incremented in steps of 0.833% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step    Fill. Charge   Vel.  Energy   Pmax   Pmuz  Prop.Burnt B_Time
 %       %    Grains   fps   ft.lbs    psi    psi      %        ms

-08.3   91    22.00   2488    1058   40558   7982     93.9    1.161
-07.5   92    22.20   2511    1078   41743   8060     94.3    1.146
-06.7   93    22.40   2535    1099   42966   8137     94.7    1.131
-05.8   93    22.60   2559    1120   44228   8212     95.1    1.117
-05.0   94    22.80   2583    1140   45533   8285     95.5    1.102
-04.2   95    23.00   2606    1161   46879   8356     95.8    1.088
-03.3   96    23.20   2630    1183   48271   8424     96.2    1.074
-02.5   97    23.40   2654    1204   49703   8491     96.5    1.060
-01.7   98    23.60   2677    1226   51176   8556     96.9    1.047
-00.8   98    23.80   2701    1248   52693   8618     97.2    1.034
+00.0   99    24.00   2725    1270   54256   8678     97.5    1.020  ! Near Maximum !
+00.8  100    24.20   2749    1292   55871   8736     97.7    1.007  ! Near Maximum !
+01.7  101    24.40   2772    1314   57539   8791     98.0    0.995  ! Near Maximum !
+02.5  102    24.60   2796    1337   59263   8844     98.2    0.982  ! Near Maximum !
+03.3  102    24.80   2820    1360   61044   8894     98.5    0.969  ! Near Maximum !
+04.2  103    25.00   2844    1383   62885   8942     98.7    0.957  !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 3% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 3% relative to nominal value:
+Ba     99    24.00   2771    1313   57747   8687     98.7    0.995  ! Near Maximum !
Data for burning rate decreased by 3% relative to nominal value:
-Ba     99    24.00   2674    1223   50780   8626     95.9    1.048

It seems to agree with your book.

Still a loading novice. I've been at it a little while and had sucess with handgun loads. I never got around to loading rifle cartridges but now I'm motivated.

I'm going to load some 223 with 77gr Sierra Match Kings with the intent on going to some Highpower competitions as soon as I can get the ammo put together and my new scope zeroed.

I've sourced all the components, some are being shipped now.

Using BLC(2), CCI primer, Starline Brass

I have a Lee Turret press

Lee Book says between 23 - 24.9 grains with the BLC(2). BLC(2) was the second powder on the list under CFE223 which I can't find anywhere. Guy at the reloading store that sold me the powder said BLC(2) is very close to CFE in terms of burn rate.

Anyone want to give me a good place to start?

[Wykyd]

Just my 2 cents but starline brass in my experience has less capacity than other brands. So I would start low (min load) and work up just to be safe

[The Tiger]

Range Report

Effectively did start loads. My book had start load of 23 grains with 2640 fps

I loaded 23.1 grains. I seated to max length at 2.26" and with my 20" barrel I averaged 2560 fps with the SMKs and I also loaded some "77gr Factory Second BTHPs" and those averaged 2540.

Barrel is a White Oak 1:7 with Wylde chamber.

I got similar results with both projectiles in accuracy and point of impact. It was really hard to tell if one was truly better at 100 yards. Groups from a rest were in the 7/8" to 1" at 100 with both with several 5 shot groups. I'm only using a 4x scope so I'm assuming the rifle can do better than me. I am happy with these results and surprised it did well first try. I'm thinking of using the cheaper factory seconds for practice and save the SMKs for when it counts.

[Tripplet918]

In stock https://shop.hodgdon.com/hodgdon-cfe-223/

[The Tiger]

Thanks, I've noticed its back in stock in a few places lately. I already have 2 pounds of the BLC(2) to work with. I might buy some CFE and save it for later.