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Discussion Starter · #1 ·
I finally got around to working up some loads with these two powders and wanted to hear what the general consensus is regarding which determinant to use in selecting a load. Plus, some of the folks here wanted me to post my results for AA2230. I understand that IMR or H4895 are probably the optimum powders for this cartridge but I have a large quantity of 2230 on hand and plan on exhausting that before switching to something else.

I was disappointed with the IMR3031 results because the lowest SD I could obtain was 17.9 with a variation of .65%. With AA2230 I was able to get the SD down to 8.1 with a variation of .30%. The bottom row of numbers is the group size for the ten shots - and they seemed kind of big but I understand that there are many variables beyond my control when using iron sights at 100 yards.

39.5 grains appears to be the most consistent and I think just under 2700 fps should produce acceptable performance out to 600 yards.

Anyone else out here have similar results with AA2230 or do you have some data for other powders that would convince me to use another?

I couldn't seem to paste my spreadsheet data as an object - sorry about that. The last rows in the columns are average velocity, extreme spread, SD, variation and group size.

1/31/11
38.5 39.0 39.5 40.0 40.5

2594 2654 2678 2728 2759
2619 2651 2687 2765 2746
2564 2654 2688 2724 2742
2571 2675 2698 2715 2761
2581 2654 2697 2748 2747
2561 2656 2695 2728 2764
2564 2682 2690 2722 2743
2604 2658 2694 2723 2756
2659 2651 2679 2746 2779
2600 2678 2703 2748 2747

2592 2661 2691 2735 2754
97.91 31.73 25.12 50.25 37.15
30.77 12.05 8.12 15.95 11.68
1.19% 0.45% 0.30% 0.58% 0.42%

3.50 2.75 2.63 3.50 2.25
 

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My 1983 mfg SA M1A will not function with such a light load of AA2230. My AA2230 is a old lot so maybe that is the difference.
 

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Discussion Starter · #3 ·
Thanks for replying. I used the 39.5 grain load to shoot a high power match yesterday and it worked well. I had one failure to extract during the prone slow fire but it came right out when I yanked on the oprod. I'm surprised your M1A won't cycle with AA2230 but I guess every gun is different. Mine is also a 1983 SA and it works fine. My powder is from the mid-1990s.
 

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im suprised you had such bad results from 3031 i have always had cosistant results from it a little dirty but it was my go to powder for everything for 15 years
i still use it but now i use imr4831 and 4895 for my riffle loads
don't remeber the gr. per load of these i keep it in my load books and look it up each time i load that way i dont get any weights mixed up
 

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Discussion Starter · #5 ·
Thanks for replying.

The can of 3031 that I used had some rusty-looking dust that collected on top of the powder bar of my Dillon powder measure. The insides of the can were rusted and I was at first a bit concerned, but it smelled fine....almost exactly like another can that I had on hand. I even had my wife who has a super sense of smell, take a whiff, and she said they were slightly different. Of course I didn't notice the rust until I had loaded about 25 cartridges so I thought, OK, I can quit here and start over with another can, or keep going and if anything looks or feels suspicious after shooting the first rounds, I can stop and pull all of the loads down. ( I never did fire the load of 42.0 grains because it was so compressed and didn't see any reason to go further).

The 3031 accuracy results were outstanding but the SD ran from a low of 18 to a high of 21. By comparison, the 2230 produced a low of 8 and a high of 30 but the accuracy was not as good as the 3031. Of course I realize the accuracy numbers are probably the most inaccurate of the process but wouldn't one think that the lowest SD and ES produce the most consistent results and thereby the most consistent accuracy?

FWIW, the 2230 loads shot very well at last Saturday's match and I'm going to take the same load to the State Mid-Range Championships at the end of the month. The avg velocity of 2691 at ten feet from the muzzle is still doing over 1600 fps at 600 yds so I don't see any reason to load anything faster.
 

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That may not be rust on the inside. When some powders start going bad they develop a brown or rust colored dust on them. if the inside of the can was rusting then that means some moisture must have gotten inside the can and in the powder.
 

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Discussion Starter · #7 ·
That may not be rust on the inside. When some powders start going bad they develop a brown or rust colored dust on them. if the inside of the can was rusting then that means some moisture must have gotten inside the can and in the powder.
Well said and thank you. When I discovered the 'rust' I searched frantically on the internet for information about deteriorated powder. About 2/3 of the sources said 'throw it away' and the other 1/3 said if it doesn't smell acrid, go ahead and use it. I guess the most conservative choice would have been to toss the powder. That's another reason I'm trying to come up with a 2230 load and might give 2520 another try with the Palma bullet as well.
 

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If the powder is deteriorating then that can explain the numbers. Don't worry about SD and such unless it is abnormally high. The target doesn't lie, pick your loads based non the groups not numbers. I suggest buying a new can of 3031 and trying that. I have yet to get single digit SD in my M1a and I am completely satisfied with the results. Don't get wrapped up in chronograph fever.
 

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Discussion Starter · #9 ·
I've got two other cans of 3031 that don't show any signs of rust so I should give them a try.

Before I got a chronograph, I used accuracy results as the sole determinant for selecting a load but I realize there are other factors that affect those results; 50+ year-old eyes, iron sights, corrective lens and that teeny SR21C target 100 yards away.

Other websites point to standard deviation and/or extreme spread as more reliable determinants. I'm not saying they're wrong or right but wouldn't those numbers have alot to do with accuracy?

I tested two AA2520 loads this afternoon. I got average velocities of 2833 and 2888 with superb accuracy for the faster load (44.3 grains) but the primers were awfully flat. I didn't test the three hotter loads because I was getting velocities way above what the Accurate Arms data said.

Zediker mentions a max velocity of 2600 fps for the 168 SMK (IMR4895) but I have not seen anyone mention a velocity that works well for the 155 SMK and does not batter the gun.

Maybe I'm approaching this thing from the wrong angle? After breaking my oprod last fall, I'm a little more cautious in selecting a load.
 

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I've got two other cans of 3031 that don't show any signs of rust so I should give them a try.

Before I got a chronograph, I used accuracy results as the sole determinant for selecting a load but I realize there are other factors that affect those results; 50+ year-old eyes, iron sights, corrective lens and that teeny SR21C target 100 yards away.

Other websites point to standard deviation and/or extreme spread as more reliable determinants. I'm not saying they're wrong or right but wouldn't those numbers have alot to do with accuracy?

I tested two AA2520 loads this afternoon. I got average velocities of 2833 and 2888 with superb accuracy for the faster load (44.3 grains) but the primers were awfully flat. I didn't test the three hotter loads because I was getting velocities way above what the Accurate Arms data said.

Zediker mentions a max velocity of 2600 fps for the 168 SMK (IMR4895) but I have not seen anyone mention a velocity that works well for the 155 SMK and does not batter the gun.

Maybe I'm approaching this thing from the wrong angle? After breaking my oprod last fall, I'm a little more cautious in selecting a load.
A lot of the load data from Accurate is pretty old and may have been from when the powder was sourced from a different country. Accurate's load data has always seemed a bit warm too. If 2888 fps was the average for the 44.3gr load what was the load for the 2833 fps average?
 

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Discussion Starter · #11 ·
If 2888 fps was the average for the 44.3gr load what was the load for the 2833 fps average?
It was .5 grains less, 43.8.

I've always loaded in .5 grain increments when testing rifle cartridges. Not sure why....maybe it's some sort of ancestor worship.

The loading data came from their reloading version 3.4. The latest version is 3.5 and the data is the same. The powder was bought in '09.
 

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It was .5 grains less, 43.8.

I've always loaded in .5 grain increments when testing rifle cartridges. Not sure why....maybe it's some sort of ancestor worship.

The loading data came from their reloading version 3.4. The latest version is 3.5 and the data is the same. The powder was bought in '09.
Thanks, That new 3.5 load guide has loads that just look too hot. I also wonder if maybe there is a different powder in the bottles.
 

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Discussion Starter · #13 ·
You know, I think you're correct. When I was testing the 2230 I obtained their velocities with a full grain less of powder. They're using a 24" barrel and the M1A is 22".

Some 20 years ago when the only source for reloading data was found in books, I noticed in a later edition that the loads for .223 were somewhat reduced. I called them and asked if they had changed the composition of their powder. They said "no" and I forget what, if any, their answer was as to why the charges had been reduced.
 

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Discussion Starter · #14 ·
I've done the last of the AA2520 testing and I think what SingleSotVictor posted sums it all up: Pick a load that shoots well on paper and don't worry about all the numbers.

I got excellent - well, what I call excellent results with both 2230 and 2520. They may not be the optimum powders for the M1A but they're what I had on hand.

What I did find out is that the Sierra 155 Palma (#2156) likes 2,750 fps in my gun. When fired near that velocity with both powders it produced decent groups;

43.0 AA2520



40.5 AA2230

 
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