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View Full Version : .223/ 5.56 reloading Questions (Hornady 68g HPBT)


tlarson
07-26-2012, 9:31 PM
Rifle: Adams Arms Piston Driven Upper 16" 1-7" Twist
Chamber- 5.56


So after reloading and shooting a bunch of 223 plinking rounds (25g H335, 55g fmjbt) I have decided to see how accurate of a load I can get using Hornady 68g HPBT Match Bullets, Varget powder and once fired LC brass.

The Lyman, Hodgen and Sierra info I have suggests a range of 23-26 grains of powder for a 69gr HPBT for .223.
The Hornandy book lists for the "Service" 223 a range of 22.7-24.9 for Varget and a 68gr HPBT.

I was planning to start with 24.5gr of Varget ( based on a load of 25gr being the accuracy load I see mostly used by people online), and work up in .3gr increments, watching for pressure signs but I will be over the Hornady max in 2 steps.
Is Hornady being very careful in their loads, or does using 5.56 brass make that much of a difference?
Will there be a difference in accuracy between 5.56 and .223 brass?

Thanks for your input

Troy

mroels
07-26-2012, 10:23 PM
The other thing you have to consider is that the hornady 68gr HPBT is almost as long as 77gr. Compare it to a 69gr SMK, it's pretty interesting to see the difference. I don't have my data in front of me so I can't tell you the exact difference. That being said I've used the same guidelines as for the 69gr SMK. Gone up to 25.5gr Varget but for my 1/9 twist RRA groups opened up above 25.2 grains so I never went higher. That being said I was using black hills brass. I did notice that this bullet likes more powder compared to 69gr SMK and 69gr Nosler HPBT. At distance it performed better than the SMK but not the Nosler and packed a bigger punch on my steel targets. At 100-200yds it didnt perform well, just around 1 moa and never under. Given your twist rate you might have more success with this bullet.

Eta: my OAL was 2.24" and seating that long bullet on top of Varget was a crunchy experience.

phish
07-27-2012, 8:35 AM
Will there be a difference in accuracy between 5.56 and .223 brass?

Thanks for your input

Troy

The only difference would be case capacity. 5.56 vs .223 designations don't mean much. I have a considerable amount of Hirtenberger 5.56 brass that is the lightest and has the most case capacity. On the other end, my LC and IMI brass is the heaviest with the least case capacity.

DarkSoul
07-27-2012, 9:40 AM
I ran some numbers out of curiosity on Quickload software, mind you this of course is like the books, you need to really load up and see what you get, but it is pretty accurate, I have done some load ups and chronoed the results, and its pretty close.

A few things to consider, I did punch in your barrel specs, 16" with a 1:7 twist, also the OAL is at 2.255, so increasing the OAL will reduce the pressure, and even at 22.5g of powder, you are already at a 5% compressed charge.

Here is what I got, notice that your intended 24.5 is creating some serious overpressure, so be careful-

http://i245.photobucket.com/albums/gg59/DarkSoulracing/Load%20Pro%20Pics/225varget.png

http://i245.photobucket.com/albums/gg59/DarkSoulracing/Load%20Pro%20Pics/23varget.png

http://i245.photobucket.com/albums/gg59/DarkSoulracing/Load%20Pro%20Pics/235varget.png

http://i245.photobucket.com/albums/gg59/DarkSoulracing/Load%20Pro%20Pics/24varget.png

http://i245.photobucket.com/albums/gg59/DarkSoulracing/Load%20Pro%20Pics/245varget.png