Help analyzing data

[DeauxJoe]

First off I'm not sure if this belongs here or in the range report section. Just let me know if I need to move it.

I'm curious to see what conclusions you guys come to based on the information I came home from the range today with.

I shot six strings of five rounds with .2 grain incremental increases in powder. This is what showed up.

20" barrel (idk what kind)
168 gr Nosler
CCI 200
H4895

1st String
42 gr
Average fps 2524
St dv 12

2nd String
42.2 gr
Average fps 2500
Std dv 6

3rd String
42.4 gr
Average 2548
Std dv 13

4th String
42.6 gr
Average 2560
Std dv 6

5th String
42.8 gr
Average 2583
Std dv 15

6th String
43 gr
Average 2570
Std dv 9

 

[DeauxJoe]

Re: Help analyzing data

Just to be more specific I'm curious to see if my fps are running about right. Could .2 gr difference make that much difference in accuracy? Or is that just my crappy shooting? Where should I go from here as far as loas development?

 

[Gene Poole]

Re: Help analyzing data

Hard to say. If you ignore #3, you've got a nice wide node at 42.5 with low SD, but #3 looks like the tightest group. But, maybe #3 is an anomaly. Maybe it just looks tight. Even a broken clock is right twice a day.

I'd shoot another round of three: 42.4, 42.5, 42.6 (maybe 5: add 0.1 to each end just for verification) and if the average to center is the same and you've got low ES and SD, call 42.5 a node and tighten it up with seating depth.

And for gawd's sake, get rid of that shoot-n-see target. You've got a decent spotting scope; just make a few crosses on printer paper with a magic marker and ruler.

 

[DeauxJoe]

Re: Help analyzing data

I'm glad you commented. I really didn't see that before. I think that's the route I'll try next. As far as fps, do you think I'm about right? Is there a method to seating depth testing?

 

[DeauxJoe]

Re: Help analyzing data

Any second opinions would be greatly appreciated.

 

[shoot4fun]

Re: Help analyzing data

Are those gator tracks in the dirt?

Seriously, if you like H4895 then stay with it. I did not have the best result using it in my 18.5 and 20 inch barrels for 308. I think your velocities may be a little low since I remember getting those numbers with H4895 and 190 SMK in 20" barrel. 42.4 looks like the middle of a node to me but I could be wrong.

 

[MALLARD]

Re: Help analyzing data

+1 Gene

perhaps you should accept that your SD is around 5-15. How precise and accuracy can an el cheapo plastic chrony be?

yes you can do a seating depth test in the same manner you did a charge weight test. Just shoot rounds with different COALS. Figure out what shot best. I hope you are using an ogive/bsc tool and measuring from ogive to base on your loaded ammunition.

try loading .010 increments behind whatever your max COAL is ( .010 incremenets behind the lands , ) , unless you feel like your COAL is already close to what's ideal , then test in .005 increments.

 

[DeauxJoe]

Re: Help analyzing data

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: shoot4fun</div><div class="ubbcode-body">Are those gator tracks in the dirt?

Seriously, if you like H4895 then stay with it. I did not have the best result using it in my 18.5 and 20 inch barrels for 308. I think your velocities may be a little low since I remember getting those numbers with H4895 and 190 SMK in 20" barrel. 42.4 looks like the middle of a node to me but I could be wrong.
</div></div>

No just standared swamp deer tracks.

Honestly I'm not partial to it. It just so happen to be what I stared with. I see a lot of guys using varget and have been considering trying it out. I guess this is that point I should probably do so.