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I am working with the Beartooth 0.452" 345 grain gas check bullet in my 45 Colt. I am wondering if you expert shooters generally find that the most accurate load is the one with the lowest extreme spread. I have tried H110 powder at 21 up to 24.2 grains and the lowest ES was 52 fps. With Lil'gun from 22 to 23.5 grains the lowest ES was at 23.5 grains and was 30 fps for 5 shots (6 shot cylinder). The best group was with 22.0 grains of Lil'gun though (1.8" at 30 yards). I wonder though if the larger groups with more powder was just me. I am still not very good with the open sights. Incidentally 22.0 grains of Lil'gun gave 1200 fps and 23.5 gave 1300 fps. 24.0 and 24.2 grains of H110 gave 1205 fps.  Thanks, Brian.
 

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Don't bet your farm on it.  I have a lot of guns where the most accurate load is not the load with the lowest extreme spread.  There is much more involved in accuracy than just consistent velocity.  Often the most consistent velocity will give stellar accuracy, but just as often it will not.  I was working up a load using 750 gr. A-Max bullets in a .50 Alaskan Encore this past Monday.  At 42.5 gr of powder, the velocity was 1129.6 fps and the ES was 24.2 fps, and the 5 shot group was exactly one inch at 100 yards.  Now, the next load was 43.0 grains and the vel was 1142.1 fps and the ES was 13.8, so one would think that this would be a more accurate load, right?  Not so.  With this load the group opened up to over two inches.  The next load of 43.5 grains gave 1150 fps and an ES of 28.2, and the group went up to 4 inches.  As you can see from this one example, ES really means nothing in some cases.  

When you shoot, the barrel vibrates in two directions, one circular, and the other like a rope, or sine wave.  If the bullet leaves the barrel when the vibration has the barrel at a peak or trough of the sine wave, where it momentarily stops before changing direction, you can bet that that particular load is going to be accurate, but if the bullet leaves the barrel while the harmonics of barrel has the barrel in movement from a hi to a low, or vise versa, the bullet leaves in a slighly different location each time and accuracy will suffer, regardless of what the velocity, ES, or MAD (mean average deviation) is.  Lyman does a much better job than I of explaining this phenomenum in their reloading manual so I suggest you get a coppy and study it.  There is a lot of good information in most reloading manuals, but most people don't take the time to read them, which just happens to be a pet peeve of mine, but I stray from the topic, please forgive me.

 The most accurate load is the one you gun likes best, regardless of all other factors, velocity, ES, and MAD be hanged. Now lets say that I get several groups that perform well, which one to choose?  That's when I rely on the chrono for input.  If I have several loads to choose from, then you can bet your bottom dollar that I will choose the load with the lowest ES and MAD for further refinement.  For big game loads, then I also take the velocity into consideration.  What good does a 4000 fps load do in a varmint rifle if it groups 4" at 100 yards, while a 3800 fps load groups into 3/8", but I will take a 2" group at 2100 fps over a 1" group at 1900 fps out of my .458 Winny any day of the week.

Long winded today.  I've got to get out more.


(Edited by Big Bore at 9<!--emo&:0--><img src="http://beartoothbullets.com/iB_html/non-cgi/emoticons/wow.gif" border="0" valign="absmiddle" alt=':0'><!--endemo-->7 am on Mar. 29, 2001)
 

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I would agree with Big Bore. Figure about 50% of the time a low ES will give best accuracy. But I think that's a bit misleading. As loads get faster it becomes less important. A 50 fps spread for a light handgun load at 800 fps average will be more detrimental than that same 50 ES with a 2700 fps rifle load.
 

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Hey Guys,

I am currently working up loads for the 280 Rem with a 170 gr. Jacketed Round Nose Sierra and IMR 4350.

This powder seems to have quite a variation in velocities with certain loads. Is this normal with 4350?

This is the first time I'm using this powder in a high intensity cartridge. Any of you guys have some experience with it?

Thanks



:cool:
 
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