Ar-15 load development

Interesting day testing loads on ar-15- Here is the data:
Grains..... n.......... avg..... Spread....Std Dev..... Total group..... Best 3
23.90..... 5.00..... 2596.40..... 49.00..... 17.47..... 1.576..... 0.746
24.20..... 5.00..... 2620.40..... 16.00..... 6.69..... 1.866..... 0.876
24.50..... 6.00..... 2670.50..... 56.00..... 21.35..... 1.866..... 0.576
24.80..... 6.00..... 2695.33..... 27.00..... 10.31..... 1.986..... 0.976
25.10..... 10.0...... 2733.40..... 54.00..... 16.97..... 1.976..... 0.576

Hornady 75bthp, chad's group buy special from a while ago

There was about 10 rounds per group, but I had some battery issues and did not get all them on the chrono. Since the lab radar was running low on juice I did not let the barrel cool as much as i should have or take my time and make sure my shooting was solid

I find the spread shifting up and down interesting. It is very clearly showing you where the nodes are. Also since I was shooting a little faster then i would have liked all the groups have a similar 10 round group of 1.5-2, but the best 3 are all 1in or lower.

the 24. 2 has a small cluster together then 2 rounds about 1in to the left so may have pulled those.
the 24.8 has some small cluster then a couple rounds 1 in high and one 1.25 in to the 10"o'clock from the main group

Think i am going to do a small batch of the 24.2 on the progressive and go back out and slow down a bit

What powder?

I haven’t been able to get those bullets to work in my guns.

Would have to ask Chad. It was not a commercial available powder but something he orders

My bulk powder that I use is Lovex D073.06. It is a very versatile powder for 223 and 308 applications. It is a slower burning powder for the heavier bullet options in 308 and 223, but also works well for the lighter one's. It burns similar to AA 2520 and Ramshot TAC, which are very good match powders for bulk loading. I have about 660+ lbs of it, and load it for (mainly) 308 and some 223. It is a powder I like a lot and shoot a ton of 308 with it in my personal rifles and ammo. I have shot 2 matches with this powder in my 20" GAP 10 308 with 155 Scenar at 2750 fps. It did very well. I also plink with it a lot in my 308 PBR (parts build rifle) that I shot in the THF tactical match in 308 qith 168 and this powder. It does very well.

https://shootersworldsc.com/D073-06/

https://shootersworldsc.com/bulk-propellant/

Range has been rained out and I have been busy, so I just got back out there...

I ran a 100 rounds on my progressive press to continue testing. It was interesting I had a buddy over using my ultrasonic cleaner and he was cleaned my bcg while he was at it. And he noticed that on my saker the stupid front piece came loose. A “feature” they added was an interchangeable front cap....well it was loose. I tightened it down and today shot multiple .5-.75 inch groups at 100. So I think it will work

Saker??

Silencerco suppreessor model

Oh. Okay...I'm completely ignorant on the subject. Obviously!

The pattern you've found is interesting. I think it would be even more interesting if you find that it's repeatable. The reason I question the repeatability is that it would be highly coincidental that the charge intervals you chose just happen to line up with these velocity "nodes." Stranger things have happened, though.

Since you're using a Lab Radar, I think the numbers are believable. Same would hold true with a Magnetospeed or a Oehler 35P, but using any of the more economical optical chronographs would turn in highly questionable results.