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.

[mike243]

Looks like it's shooting good, I am torn about my local range, I didn't renew last year due to shoulder surgery and it starts July 1 and runs for a year, $75 if only for a few months makes me pause. I will be better off putting that towards ammo or loading supply's. Might pu some 80g for the arc Saturday as Bass Pro has some in stock. Thanks for posting your results,