6.5 Grendel Preferred Loads
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This is a sticky topic.
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Bob-
Since you've indicated in the past that the attention to details in the loading process is a contributor to your consistently positive results, do you find runout and/or neck concentricity factors to same or best addressed in die setup? I'm more than occasionally frustrated with wide disparity of one or both, even when trying to pay particular attention when sizing brass. Using Redding FL comp dies with 288 bushing. Some runout .001 or less, the next piece can be out by .005, without any seeming variation in technique. Your comments welcome.
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Bob I think this is a good idea. I have heard that the Federal 308 Win Gold Medal is a load that is consistent in most arms and is widely used in matches. They have found a load that just plain works. So it would be great to have loads that when someone new comes aboard the site we can direct them to loads that have been found to be consistent with a number of members. I think what we need is a sticky with a spread sheet on the 1st page that is updated. They have something like this on arfcom in their reload section.
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I'm on-board with this. I have some factory Hornady 123gr AMAX box that I will chrono and shoot for accuracy in my 16", ER Shaw AA button-rifled beater. I have had great results with the 123gr Lapua Scenars from Precision Firearms (Factory loaded moly Scenars) with 7fps Extreme Spread, and a decent .79" 4-round group.
So let's get the initial standardized testing loads out there:
123gr AMAX Hornady box ammo
123gr AMAX 28.5 grains IMR8208 XBR
100gr AMAX 34.0 grains CFE223
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Yes, that is the concept I'm looking to replicate. The 308 Winchester Gold Medal load using the 168 grain Sierra Match King shoots really well in nearly all .308's out to 600 yards or so. The Black Hills .223 77 SMK load does the same. Both of them will shoot less than one MOA out or almost any decent barrel and if they don't, you really should be looking at what is wrong with the rifle.
In the High Power community there are several know loads that will duplicate or better these loads. That is what I'm looking for, a factory load that shoots well and several handloads that do as well. I'm proposing that the Hornady 123 A-Max factory load is that load. But I want confirmation from many people. Then I want handloads that do as well or better documented.Last edited by Guest; 10-02-2012, 12:05 AM.
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Let me begin by reverse engineering the Hornady factory load. Obviously it uses a Hornady case which uses a small rifle primer and the Hornady 123 A-max bullet, but what primer, what powder, what charge weight, what neck tension, what COL and so on.
Beginning with the easiest to measure the COL 20 rounds from lot #3121949 were found to be very consistent measuring a nominal 2.250" and varying from 2.249" to 2.252".
The next measure is the length to the ogive which the same 20 rounds measured 1.671" to 1.674". In my experience this is very good control.
Those measurements out of the way I then ran all 20 through the concentricity gauge to measure bullet runout and again found very good control with 19 out of 20 measuring less than .003" run-out and only one round exceeding this at .004". My experience has been that anything .003" and under is undetectable out to 1,000 yards and even .004 would still keep it in the ten ring.
Neck tension seems to be light, loaded rounds measure .290 to .291 while cases with the bullets pulled measured .289. I realize that the brass may not be elastic enough to snap back to original measurements but I doubt that neck tension exceeded .002" as origianlly loaded judging by how easily the bullets pulled from the case.
So with those preliminaries out of the way, three rounds were selected at random and disassembled. I found them to contain 29.1 grains of a ball powder that appears identical to CFE223 under a microscope but there is no guarantee this is the powder used.
Last edited by Guest; 10-02-2012, 02:25 AM.
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Originally posted by stokesrj View PostLet me begin by reverse engineering the Hornady factory load...
...I found them to contain 29.1 grains of a ball powder that appears identical to CFE223 under a microscope but there is no guarantee this is the powder used.
Unfortunately, Hornady likely uses a powder unavailable to the public, but perhaps we might learn something different.Drifter
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Yes, I spoke to the head ballistician at Hornady, he said it isn't CFE223 and I already knew that anyway since 29.1 grains would come no where near the velocities we see from the factory load, but it looks identical. He said he was not allowed to disclose the powder used so I explained to him what we were trying to accomplish. He then said if I were you and trying to accomplish what you are trying to accomplish then use Accurate 2520.
I surmise they are using a bulk grade of the same powder. At least we have a place to start, they gave a range of 28.4 to 29.3 grains.
Bob
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Originally posted by sneaky one View PostRJ., you should also include hunting bullets, not only target units-fair is fair.
Bob
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Hornady's powder is most likely a variant on their Superperformance powders. Some time ago, perhaps during development, someone brought up that it was a St. Marks powder, and Hornady never disputed that, which also fits the Superperformance envelope. 2520 is not as temp stable as the Hornady loads seem to be, so that's a non starter for me.
Interesting that it looks like CFE, because I have seen no copper fouling from the factory loads, and I've noted almost no copper fouling after I shoot it behind my handloads, regardless of what powder I use. That could be my barrel, but it is intriguing.
Does it smell like CFE, which has a very distinctive pepper smell?
Drifter beat me to the temp. sensitivity issue.
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