ElDX seating depth test.

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kilotanker22

New member
So I finally narrowed down my powder charge for this bullet with Reloder 16 in my Savage Tactical rifle.

So I decided to do a seating depth test. I started at the lands, then .045" off, then .080" off and finished with .120 off.

What I found was that the .080" load definitely shot better than the others. I have not gotten home to measure yet, so the following are estimated.

On the lands was almost 2". Elevation was good, but horizontal was pretty wide.

.045" off was roughly .75" group

.080" off is approximately .3" group

And .120" off yielded around .9" group.

I will post some.phottos later.
 
Got time to measure the groups. They are marked with distance to lands and group size. I measure the groups by laying the target on my table and flattening the holes so I can see the entire bullet holes. Then I measure outside to outside of the two furthest holes, then subtract bullet diameter. I feel like that is a more precise way than guessing the center of the holes.
 

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I loaded some with the new StaBall powder and seated to book COAL, 2.800". First Time I ever got decent data on that bullet.
 
hooligan1 said:
I loaded some with the new StaBall powder and seated to book COAL, 2.800". First Time I ever got decent data on that bullet.
Click to expand...
at .080" off where I found the best results I ended up with an OAL of 2.829".

I was about to give up on this bullet in this rifle since I knew the rifle was capable of better.
 
Now you want to try 0.060" and 0.100" to see if you are really in the middle of that flat spot. If either one of those do equally well while the other does not, go between 0.080" and the other good one and go for a 10-shot group. If your 5-shot group was truly representative, you can expect a truly representative 10-shot group to be 28% bigger.
 
Then you get to skip that one! See what 0.060" does and refire your 0.080" to make sure what you got before is representative of what you can expect from it.
 
Well I have enough powder left for about 18 rounds and only 32 bullets. Hahahaha, I might not be loading anything for awhile until this Covid-19 shut down is over. Can't get anything locally that I need. Everywhere is sold out of the powder online (that I know of)

I should ha e bought that 8 pound jug of powder Instead of just two
 
At what dist from lands did you develop your load?

With 18 rounds of supplies, I would either load 18 at 0.080” or I would load 5 at 0.070”, 0.080”, 0.090”.....and 3 to season the bore before shooting groups.

Why are your oal choices varying by different increments?
 
The first post says he started with land contact and moved back.

One of the things the Berger article points out is that with the long ULD bullet shapes, short changes in jump don't have much effect. They limit it to 0.040" per step for hunting load development purposes and 0.030" steps for match shooting purposes. From Dr. Lloyd Brownells theory of gas bypass and pressure, a long ogive has to be moved more than a short one does to change the bypass gas exit annulus in the throat by a given amount, so that makes sense to me that any introduced delay will match that.

For the above reasons, I would still be inclined to shoot a small set (5) at 0.060", then save the other 13 rounds either for a bigger 0.080" group or, if the 0.060" shoots just as small as the 0.080, I would figure the middle of the sweet spot was between the two and go to 0.070" for a final larger group test, not because it would be any better than the other two, but because targeting that spot would give me wiggle room for as much seating depth error as I can get. It might also tell me if the Berger theory pans out in this combination. If not, then the smaller steps would make sense to try when enough powder is available. Got to wait for the hoarders to decide they should save some of their money for the duration of the social isolation period.
 
I guess I read it as first I determined my charge at a fixed oal. The I worked on my oal.

I was just asking what the fixed oal was....
 
Also the reason that I jumped from the lands to .045" off is because .040" off won't fit in the magazine. And I figured the .005" difference would still yield a reasonably representative result if compared to .040" off the lands.

Update: I called my LGS today and he did end up having 3 more pounds of Reloder 16 powder and two more boxes of the 143 grain ELDX bullet. So I asked them to set aside what they had and I will pick them up Monday.

Now I am considering buying some new brass for this particular rifle. I currently have around 200 fire formed Winchester cases for this rifle. I have been throwing them out after 5 firings. I throw them out as soon as the primer pockets loosen just a little. So that leaves me about 1000 shots before I need new brass.

I was thinking about Lapua, but they don't make large rifle primed brass for the creedmoor. Although I might just buy more Winchester for now and buy the Lapua when I rebarrel this rifle after another 2000 or so rounds. Right now my round count is about 600
 
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