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Posted: 3/26/2012 5:26:57 PM EDT
I have attached a picture of a group that I shot at 100yds I'm trying to figure out how to measure group size.
I measured the farthest 2 holes and subtracted .308 which is the bullet diameter.  Am I doing it right?  

1.1"––-.308"=.792



I shot this group using  a .308 cal AAC-SD using 46.6 grains of CFE 223 and a 168 grain SMK.  I tried using charges from 46.6-48.0 grains but the groups just kept getting bigger and bigger, I could also tell the velocities were getting pretty high because the rifle was beating my shoulder up pretty badly.  I would be able to tell you velcoities but I shot my chronograph while sighting in my scope.  I set the chronograph up and shot 4 shots through the chronograph stopped to jot some notes down, I guess the wind shift the chronograph and I didn't notice it, luckily it was just one of the legs that hold the sun screens up.  

Do any of you guys use CFE 223 for .308?


Link Posted: 3/26/2012 5:36:44 PM EDT
[#1]
i usually measure from center of each of the farthest holes, which would do the same as measuring from the outsides and subtracting bullet dia
Link Posted: 3/27/2012 4:58:33 AM EDT
[#2]
so no one loads 308 with CFE
Link Posted: 3/27/2012 10:29:58 AM EDT
[#3]
Link Posted: 3/27/2012 12:33:30 PM EDT
[#4]
I figured it out, it seems that it doesn't like it when you take a picture with a camera so I scanned the target and it worked

Link Posted: 3/28/2012 6:23:06 PM EDT
[#5]
Quoted:
I have attached a picture of a group that I shot at 100yds I'm trying to figure out how to measure group size.
I measured the farthest 2 holes and subtracted .308 which is the bullet diameter.  Am I doing it right?  

1.1"––-.308"=.792

http://i1187.photobucket.com/albums/z381/peligro113/IMG_06451.jpg

I shot this group using  a .308 cal AAC-SD using 46.6 grains of CFE 223 and a 168 grain SMK.  I tried using charges from 46.6-48.0 grains but the groups just kept getting bigger and bigger, I could also tell the velocities were getting pretty high because the rifle was beating my shoulder up pretty badly.  I would be able to tell you velcoities but I shot my chronograph while sighting in my scope.  I set the chronograph up and shot 4 shots through the chronograph stopped to jot some notes down, I guess the wind shift the chronograph and I didn't notice it, luckily it was just one of the legs that hold the sun screens up.  

Do any of you guys use CFE 223 for .308?




I am probably going to, soon as I run low on RG4895 and Varget.  Hodgdon labs seems to think it is a winner for .308.
http://www.hodgdon.com/new_prod.html
Link Posted: 3/28/2012 6:51:11 PM EDT
[#6]
That best group I shot so far was the group in the picture you see above, using 46.6 grains which is the minimum load on the hodgdon website, then I load all the way up to 48 grains in .5 grain increments but the groups just kept getting bigger and bigger.  Do you guys think that it would be okay if I went .5 - 1 grain under the min load?  I find it weird that the groups went from .78 moa with 46.6 g all the way 4 moa with 48 g.

Here is the complete target the loads go from left to right 46.6, 47, 47.5, 48, and I didn't fire the 48.5 since the group sizes were beginning to get huge.  The 47.5 and 48.0 groups are only 4 shots since I couldn't get a couple of the rounds to chamber.

Link Posted: 3/29/2012 8:55:47 AM EDT
[#7]
That looks like something other than loads to me- flinch?  Technique?  See if you can shoot a couple more groupings with your 46.6 gr load.  I'm betting you will have different results.
Link Posted: 3/29/2012 12:45:05 PM EDT
[#8]
The CFE loads were my last loads I had already shot 75 rds trying other powders so my shoulder pocket was killing me which possibly could've lead to me flinching.  How can you tell it's something else and not the powder from looking at the picture?
Link Posted: 3/29/2012 8:13:23 PM EDT
[#9]
I guess the reason I think it is something else is because of the dramatic jump between relatively small increases in powder charge.  The jump between 46.6 and 47.5gr is just not natural, especially in this caliber.  308 is normally not this sensitive- unless there is something about CFE that your rifle just plain doesn't like.
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