Closing the loop

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BobCat45

New member
CAUTION: The following post (or a page linked to) includes or discusses loading data not covered by currently published sources of tested data for this cartridge (QuickLOAD or Gordon's Reloading Tool data is not professionally tested). USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assumes any liability for any damage or injury resulting from the use of this information.


Early this month I posted a question about the prudence of substituting Accurate Arms 4064 for IMR 4064 - not direct charge weight substitution, just whether or not it was feasible. What raised the question was that the manufacturer lists zero data for that powder in .223 Rem, while they do list lots of data for their other powders in that caliber. The thread is at https://thefiringline.com/forums/showthread.php?t=612344

Got some good advice, for which I am grateful!

Long story short, it worked out fine. I loaded a couple of rounds very low, a few a half a grain higher, and so forth until I had some that were half a grain above the IMR 4064 load that works great in my AR spacegun. All of them shot fine, there was no excessive primer flattening, ejector marks on case heads, or any other "pressure signs" - and all the cases ejected at about 3-4 o'clock, just like the Reloder 15 and IMR 4064 loads that are "known good" in this rifle.

So, just writing to say "Thanks!" and close the loop.
 
5

5whiskey

New member
So I am toying with accurate 4064 as a substitute for IMR 4064. Like you, I understand it won’t necessarily be a grain for grain substitute, but so long as it’s similar enough to be suitable for all of the cartridges which I use imr4064 for. Which, right now, is almost all rifle cartridges I actually shoot often. IMR4064 is excellent in old battle rifle class calibers such as 30-06 intended for the M1, the .303 British, 7.5 Swiss, 7.7 Jap, 8mm, etc. Well there are other suitable powders but I’m kinda used to 4064 now (and it is an excellent powder for this class of cartridges). Wondering about accurate 4064.

Of course I know to start low and work up. That’s a given. Another part of me wants to give blc2 a go. I have sources for both at a price I’m reluctantly willing to pay.
 
B

BobCat45

New member
I think you will like the Accurate Arms version. It meters better than IMR 4064 but seems to be a little less energetic - 24.5 grains, the primer looks the same as 24.0 of IMR. This makes some sense in terms of their relative positions on the urn rate charts, in light of Unclenick's explanation of how those charts are derived.

Neither are "good" in the RCBS Uniflow - they want to crunch. In the Lee measure The IMR gives about +/- 0.2 grain, which is not enough to worry about for a 48 grain load in the Garand, with iron sights at 200 yards, but is pretty sloppy for a 24 (nominal) grain load at 600 yards. The AA gives an extreme spread of about 0.3 grains in ten throws, repeatedly. It is probably good enough, but for Midrange Prone I will continue to throw low and trickle up every charge, just for psychology/confidence.

My initial hesitation was generated by the fact that there was zero handbook data for AA4064 in the .223 Rem, and I wondered if there was some esoteric reason it was inappropriate.

I think the real reason is that Accurate lists quite a few powders - LT-30, LT-32, 2200, 2015, 2230, 2460, 2495, 2520, TAC, and so forth - for .223 and they may be "better" in that cartridge, but AA 4064 seems not dangerous or unacceptable. This is in my rifle, with an 80 grain Sierra Matchking, seated over mag length.

Anyway, have fun!
 
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