Loads starting to come together

[Diesel Pro]

Finally got some time to run the 6ARC using 103 ELDX and 90 ELDX.  Top 8 are 103 and bottom 4 are 90.  All 5 shot groups at 100 yds portable bench at my in wood range protected from most wind.  Temps around 32f.  I had a little mirage and eye watering to deal with, but seems when I was patient enough to wait a bit things cleared.  Using my Leupold VXIII 4.5-14. I prefer a little better glass for my load development, but this one was handy.  I also prefer a distinct + to help align the crosshairs so I altered my targets for next session. 

First group looks decent unfortunately not zero'd quite right.  I plan to explore the next steps higher on the 103 to see if the SD comes down.  My 90 gr go-to loads are not shown here.  I went where QL told me to go and put the other loads on a different target.  They picked up speed and higher SD with the suppressor so I am slowing them down a bit. 


Gun is Cobalt Kinetics AR 15 SPR Elite with 22" Proof carbon barrel.  I'm impressed, especially for a semi auto.  

Powder used is LVR.  Charge weights approaching or exceeding max on the 103. 


           

[SpeyRod]

What was the 3rd 90 gr load and its speed? A friends Proof barreled are shoots the 103 factory loads extremely well.

[Rickhem]

There are some really nice groups in there, and thanks for shooting 5 shot groups.
That 28.4 load looks really nice!

[Diesel Pro]

There are some really nice groups in there, and thanks for shooting 5 shot groups. 
That 28.4 load looks really nice!

28.9  I don't always do a good job of closing the top of my 9's especially with a sharpie and light contact.

After the session that I posted, my suppressor was tight coming off and spun off the CK muzzle device so I had to reset it and added a bit of blue loctite.  I also changed gas blocks to a Superlative and run it in the bleed off setting about 48 clicks out.

SD at 28.9 is a bit high for my liking.  I was out again with 29, 29.1, 29.2, and 29.3 pushing up past max.  It was uncomfortably cold out so my groups were so-so. The 29 gr charge had a much better SD and a decent group so that is what I am focusing on right now.  I'm kind of torn between the 90 and 103, but leaning more towards the 90.  I'll comment more in another post.

At recent session I found a pretty substantial POI shift (approx 4" down and right)  that left me scratching my head.  I think it mostly came from the muzzle device remount near as I can figure.  It's indexed same/properly so not sure yet  Velocities remained same/similar.  I use a Bobro QD mount and at first I questioned it, but I followed up the session with a quick zero check of a thermal and found similar shift.    

[Diesel Pro]

What was the 3rd 90 gr load and its speed? A friends Proof barreled are shoots the 103 factory loads extremely well.

The 3rd group 90 ELDX is 29gr charge

Next session I found that the 103 likes that same charge. 

For the 90 I'm torn between 30gr charge and 29gr, but the 30gr charge is 100fps faster.  The 103 I had to change my zero. The 30gr charge target is 10 rds and for whatever reason seems to show 2 different groups.  Could be a cheek weld issue would be my guess.
   

   

   

[Rickhem]

28.9  I don't always do a good job of closing the top of my 9's especially with a sharpie 

I actually have that same issue.  The QA people took a while to get used to reading my lab notebooks.  

Groups look really good though, and you can see the progress.  Looks like the 28.8 to 28.9 charge is a good node for you.

[Diesel Pro]

28.9  I don't always do a good job of closing the top of my 9's especially with a sharpie 

I actually have that same issue.  The QA people took a while to get used to reading my lab notebooks.  

Groups look really good though, and you can see the progress.  Looks like the 28.8 to 28.9 charge is a good node for you.

29.0 the SD dropped to single digits and IIRC 29.1 the velocity dropped a touch.

I've been a bit down on the semi auto for accuracy, but once I changed my bench technique/setup it got much better.  Between this one and my BCM .223 i do have a pair of nice tack drivers. 

The Cobalt has a Geiselle SSA 2 stage trigger and I hate it.  Probably not a bad trigger, but I'm not a 2 stage trigger guy.