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Does anyone know why the Hornady manual in the 223 section only goes up to 60 gn bullets? They have a service rifle section for the 68 and over, but unless I'm mistaken a service rifle uses a NATO chamber and throat. Right? I'm trying to get good data for a 223 Rem Mod 70HV with the 68 HPBT and this manual has me baffled at how it is put together..
For what it's worth I shoot a 69gr Sierra TMK behind 25.0 Varget in Hornady brass loaded to 2.26". Gets me right at 2980 fps and 1/2 moa. In my Starline brass I have to drop .5 gr due to the lower case capacity.
Look at the 223 Remington Service rifle data section that is right after the 223 Remington data section - page 157 and 158 of my 7th edition.
It includes data on 68 and 75 grain bullets s.
They tested with a 1:9 twist barrel.
Apparently, they have never heard of 1:7 twist HBARs.
True. I don't think the Army Marksmanship Unit uses 9 twist barrels in their service rifle , but I could be wrong. I think Hornady used a 9 twist just to show their bullets would stabilize spinning slower. However, IF that is the case them why test service rifle loads in a twist the average 223 is barreled in?
What I DON'T understand is why the standard 223Rem section only goes up to 60 gn bullets when half the 223 shooters are shooting the longer boat tails. Also, the service rifles I shot were NATO chambers and with the longer throats which 5.56 NATO data really isn't compatible with the average short throated 223... I think Hornady is screwing up with their manuals. It's fine they provide gas gun data, but not OK to be limiting my bolt rifle data to 60 gns.. I could get away with sierra 69 gn data, but the two bullets have different bearing surfaces.
Maybe the 1 gn difference in the Hornady makes the pressures equal to the 69 with the shorter bearing surface? No doubt I'm getting too deep into this.
I think that Hornady has not caught up with the modern times/guns in regard to the 223 data. The original twist rate for 223 was 1:12 and 60gr is as high as you can go with the slow varmint bullet twist.
Quote:
Originally Posted by PaddyD
Because the loading data is for a Remington 700 with a 1in12 twist that will not stabilize bullets over 65 grains. So this leaves out the Hornady 68 bullets and above.
There is nothing wrong with the Hornady manual and its .223 and 5.56 reloading data. The data varies by the twist rate and throat length and you need to "Know Thy Rifle".
My Savage .223 has a 1in9 twist and a throat longer than my AR15 rifles.
My Ruger American Ranch Rifle is marked 5.56 NATO and has a 1in8 twist.
My AR15 A2 HBAR has a 1in9 twist.
My AR15 carbine as a 1in7 twist.
Quickload has three listings for the .223 and 5.56 and are based on the rifles twist rate and throat.
Bottom line, you will have .223 rifles with 1in 14, 1in12 and 1in9 1in8 and 1in7 twist rates and AR15 rifles with 1in9, 1in8 and 1in7 twist rates.
So find out what the twist rate for your .223/5.56 rifle and check your throat length, and then pick your appropriate load data.
https://i.imgur.com/qMYSJ9V.png
Look at freebore diameter (G) and freebore length (N) below, and this is just "some" of the .223/5.56 chamber variations.
https://i.imgur.com/wjAOlWq.jpg
I get all of that, but in the .224 caliber f service rifles, I tend to think of NATO chambers . Therefore, I was questioning the data for use in the standard 223R chamber.. To me, it was misleading to call it "Service Rifle specific data, just because it was tested in a 9 twist vs 12 twist.. I was wondering about pressures generated from that data in my M70 which is not a service rifle and does not have a NATO chamber. They only list how fast the twist was and not if indeed tested in a military chamber.Quote:
Originally Posted by bigedp51
In regard to the original question, a 1 in 12 barrel will not stabilize a bullet heavier than 63 grains. Hornady used a 1 in 12 barrel for their test. Speer list bullet weights up to 70 grains and I suspect there are others.
I just noticed that Noslers online data is the same way. 223 Rem(1:12) up to 64gr. and 5.56(1:7) up to 80gr.
Don't know?!
Hornady manual for 223 remington lists the rifle that the loads were tested for. 35 grain to 60 grain was tested in a 26 inch 1 in 12 twist, Service rifle in an AR-15 20 inch 1 in 9, 5.56 NATO a 20 inch 1 in 7 but maximum pressure is listed higher and chamber throat is longer. I would use care using the 5.56 NATO data unless rifle is rated for the rounds.
Sierra also lists bolt rifle 223 data for all their bullets too, not just for the lighter ones. . For some reason Hornady thinks only the semi auto service rifles use anything over 60 gns.. I'm not complaining, but I find it odd.Quote:
Originally Posted by Robinhood
The Hornady manual is also very conservative in their load data maximum compared to Sierra, Nosler and Berger.
When the litigators get too close to load data, you get some very conservative results.
Sierra uses data actually gathered on the range for their tables, list rifle and barrel length used and show load data for incremental velocities.
Hornady also shows load data for incremental velocities and it appears that they also gather their data on the range because they list the rifle and barrel length used.
Nosler also appears to use data gathered on the range but lists starting loads, an intermediate load and a max load.Berger uses QuickLOAD simulator software derived data rather than actual fired data and shows only starting loads and max loads.
None of the manuals list the temperature at the time of testing. See page 14 & 115 of the Berger Reloading Manual.
I have no problem with that since I am a heavy user of the QuickLOAD software.
[However, QuickLOAD software uses a default temperature setting of 70 degrees (the European powder test norm), so Berger's listed velocity numbers might be a bit higher (about 1 %) than data from U.S. manufacturers that would normally be based upon a 59 degree powder test norm.]
Does anyone here know if hornady load manuals are listing the powders by burn rate or any other order or just random??
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Hornady did add 62 gr and maybe a couple others on their errata site that you can download free:)Quote:
Originally Posted by PaddyD
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https://www.hornady.com/support/load...andbook-errataQuote:
Originally Posted by PaddyD
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Hornady Manual lists powder from fastest to slowest relative burn rate (top to bottom on each load listing).Quote:
Originally Posted by Ted_Feasel
Mike
Awesome, thanks for the reply, I suspected they did from looking at burn rate charts but wanted confirmation:)Quote:
Originally Posted by MikeT124
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I think that if you look at the Hornaday loading chart for any given bullet/powder combination, you'll notice that the chart is ordered by charge weight at maximum pressure (red colored cells).
While the reader can infer a correlation to burn rate, something that has no fixed number, one can definitely see the correlation to charge weight measured in grains. I then charge some cases with several powders to see which one will still leave just enough room for bullet seating at the max charge weight, adjusting for settlement techniques (how you settle the powder after charging and before seating the bullet). In some cases, a drop tube may be necessary to get enough settlement for reliable seating at best grouping charge weight. I find that a 69 gr Lapua Scenar-L seated .005 into the lands shoots best with the case charged so full of Varget that even with a 10 inch drop tube I cannot seat the bullet out of the lands and still get reliable bullet seating due to compression of the charge. Therefore I may have to try a different or more dense powder if I want to chase better accuracy/consistency. I am already using brass with the greatest capacity I have, and this is where using mil spec brass would be a definite disadvantage due to it's thicker walls and lesser capacity.
Although your best performance/accuracy may not occur at max recommended charge, the chart gives you the ability to select a powder that will allow you to charge to as near to 100% full as possible and still get reliable bullet seating. Incidentally, the Sierra manual lists percentage of full in charge weight while Hornaday does not, so one can indeed infer that percentage of full may be important to some.