75 gr. Hornady A-Max handloads for .223

[JRiddle]

I have some 75gr moly coated A-Max, I was wondering if anyone has any good loads worked up?  I just got a cz-527 varmit, 24" bbl and 1 in 9" twist.  I like loading with ww748 because of the lower flame temps, but also load with 3031.  Also if anyone has this rifle, let me know what bullet weights you've found work best.  I load 45s, 50s, 55s, and 62s, for my ar15, mini14, and contender.  I tried some 75's, but they were too long to feed in the ar or mini, and 1 in 12" twist on the 14" contender wont stabilize. Thanks, JR

[LaOtto222]

My 223 are of a slower twist. either 1 - 12" or 1 - 14", so I do not have first hand knowledge of the heavier bullets. However, I have read that the 75 grain A Max is on the raged edge of stabilization with 1 - 9" twist. Some say that they get good groups with them and some say they do not. I have even read where the bullet destabilizes when it gets out to 400 yards and beyond. Your only way of knowing is to load some up and give them a try. You will want to get your velocity up in the 2700 fps range for sure. H 4895, Win 748, RL-15, BL C2 are a few powders that should get you where you want to go. I am not sure you will be able to reach 2700 fps with IMR 3031, you will have to try it to find out. Good Luck and Good Shooting.

[hardly]

I have a Tikka Varmint with 1 in 8" twist.  Shooting 75 gr A-Max non coated.  24.1 gr. Varget, Winchester WSL primer and seated .015 off.  Very accurate load in this gun.

[GrampaMike]

JRiddle,
My software tells me the Muzzle Velocities needed for stabilization are as follows:

1:12 4965 fps
1:10 4639 fps
1:9   4389 fps
1:8   4040 fps
1:7   3530 fps

[LaOtto222]

GrandpaMike - I certainly have not shot any of the A-Max 75 grain bullets - but I have read where they are stabilizing them with out exception at 2600 fps with 1 - 8" twist barrels. Hornady 7th edition has them going out a 20" 1 - 9" twist barrel at 2600 - 2700 fps and do not mention any stabilization problems. In fact they recommend them being shot at 600 yard matches, but they have to be loaded single in a AR-15 type weapon, because they are too long for the magazine. I have read that shooters have had mixed results from 1 - 9" twist barrels. Like I said I have not shot any to confirm any of this. I have been thinking about building a 22 BR with a 1 - 8" twist to shoot these very bullets at some where around 3000 fps. I think they will stabilize OK. Sierra 5th edition recommends a 1 - 8" twist barrel with their 80 HPBT bullet witch is about the same length or longer than an 75 grain A-Max. When you get into the 85 and 90 grain bullets you will more than likely need a 1 - 7" twist to get them to stabilize. I have no software to figure this, I have just taken data out of reloading manuals, manufacture's recommendations and results from different people reporting on the 'net. I realize that what people report on the internet can be doubtful at times, but there is the loading manuals that should be fairly accurate. I do not want to flame you at all, but the results from your software seems a lot too high on velocity - like I said I have not got results from my own experiences...just reloading data and the internet, so your results could be accurate. There are few cases that could push a .224 75 grain bullet at 3530 fps, if any.

[JRiddle]

I appreciate the replies,  I've figured that I'll have to break 2700fps to stabilize, but still wondering how long that will last? I want to drive tacks at 400yds, I just know at some point it's going to start tumbling.  GranpaMike I thank you for your trouble of running my scenario through your software, but I don't know of a way to get 4389fps on a 75grainer out of a .223, I would double check any and all results from your software with a reloading manual before loading it, as those number you just posted seem off the charts.  I've been reloading .223s for over 20 years mostly 50s and 55s, this is just something 'new' I'm working on, I'll keep you posted on my results.  But any future readers don't hesitate to post..thanks again, JR

[GrampaMike]

Sorry guys, my numbers should have been more complete.

Stability Factor = SF

SF < 1.0   Bullet is NOT stabilized.
SF = 1.0   Bullet is marginally stabilized.
SF = 1.3   Bullet is fully stabilized.
SF = 1.5   Bullet is maximally stabilized.

Hornady 75 gr A-Max is 1.070" long

           SF = 1.0     SF = 1.3     SF = 1.5

1:12     4595 fps     4851 fps     4965 fps
1:10     4106 fps     4475 fps     4639 fps
1: 9      3731 fps     4187 fps     4389 fps
1: 8      3207 fps     3782 fps     4040 fps
1: 7      2442 fps     3195 fps     3530 fps


I leave the SF set at 1.5 in my software by habit.

For those who do not have ballistic software to do the heavy lifting.

Here is the formula to use in EXCEL.

MV is Muzzle Velocity needed.
BW is Bullet Weight in grains.
BD is Bullet Diameter in inches.
TR is Twist Rate 1:8 use 8
BL is Bullet Length in inches.
SF is Stability Factor (plug in a value from the list above).

MV = 5705 * (1 - ((BW * (20.62 * (BD ^ 2.25)) ^ 2) / (TR * (BL ^ 2.25)) ^ 2) / SF)

Hope this clears things up.
Mike

[OR-E-Gun Bill]

Hornady 75 gr A-Max is 1.070" long

Just out of curiosity, is the measurement above correct?
I have measured the Hornady 75 gr. A-Max that I have and they are 1.107" in total length.

[GrampaMike]

OR-E-Gun Bill

Just checked, I do not have any actual 75gr A-Max bullets, my info came directly from Hornady.
Maybe it was a typo from them, not a good thing.  Will send them an email and ask.

Thanks for checking