Staball/140 SMK/6.5CM initial test and requested input

[mark5pt56]

Also posted on SH to maximize input. Initial test today with the Staball powder. 24" AI AT stock gun, Atlas front, bean bag rear.
WInchester Staball
1X Hornady brass, sized on standard RCBS die with expander ball(more on this)
Fed 210M
140 SMK
2.8 OAL

300 yards-Forgot Kestrel--72 F 30.03 pressure approx 90ft ASL

I'm leaning on the 43.5-44.1 on the high end and 42.6-43.2 on the low? My plan is to load and group test at 100?, picking one of the nodes, maybe tweaking the charge weights, thinking .2 increments and 3 total charges?

Requesting input.
One thing that will change, I loaded these being sized as stated. A 2 week delay in testing has me switching my sizing. Removing the stem, size as before full length and bumping .01-.015, best I can measure and using a .001 Mandrel that's arriving tomorrow. Hereafter, they will also be annealed after every firing.




Initial target, made adjustment as stated


the three plotted

[gaijin]

With respect, I’d expect much better groups with your equipment.

I have no experience with Staball, but RL16 and 4350 have been no greater than .75 MOA out of 3 bolt guns and an AR10 in 6.5CM. This with Hornady 140 ELD Match and 143 ELD X.
I would bet a lot the SMKs are not the issue.

Have you tried other powders?

Add: I’m using SRP brass, however the switch from LRP had no bearing on accuracy, but increased case life with hotter loads.
The 6.5 has been one of the least temperamental cartridges I’ve ever loaded in regards to a accuracy.

[gaijin]

Dupe.....

[markm]

For 300 yards, the groups look pretty good to me. The two right side groups have 3 of the 4 in the same vertical plane. I'd be sniffing around there after the neck situation is good.

[gaijin]

Shit. My apologies, missed the 300 part......

[markm]

Shit. My apologies, missed the 300 part......

I was hoping that was the case.

[mark5pt56]

I was shooting what's left of my old Amax load at 628, with conditions, maintain Moa or less at that distance. I had picked up a bunch and now almost out. I'm leaning on maybe 43.6/.8/44 or 43.8/44/44.2. Slight, very noticeable bolt lift at 44.4.

[gaijin]

Personally I try to resist the "mo', betta, fater, further" mindset with load development. It's difficult however, because I'm an American.
I am not implying you experience this.

Chasing max velocity at the cost of pressure sign seems pointless with the 6.5CM. Brass life is shortened, particularly using LRP brass.
High 2700's to low 2800's seem to be the sweet spot for the 140's (depending on barrel length) and about all the cartridge is capable of.

One of my guns (20" barrel) only generates 2740 FPS but 8.4 MIL gets me to 1K with the 140 ELD M.
It's a 6.5CM; accurate, easy to shoot. I just enjoy the ride.

[mark5pt56]

I go for the accuracy first as well, if the velocity comes along with it less any pressure, that's great. Not sure if you are thinking I'm over max, seeking the fastest or not. The charge weights with this powder are not the same as with others so it may appear they are "over max" based on that, I don't know. For info, Hodgdon list 44.4 max with a 142 SMK.

Looking at it all, I think there's a nice flat spot at the 43.5-44.1. Think I will retest at 43.6/43.8/44. The low node looks ok, but not as tight on vertical, very close though. I can always revisit those. I did the JBM math and the difference using 2650 and 2750 velocity for wind. At 300 it's so small I doubt any shooter could work it, at 600 it was .01 for each mph, yes .zero1, so .1 (one tenth) for a 10 mph wind. There are very few that can say or even work the wind better than that. I didn't look at 1k or further.

My old load, only one I had for this one is 42.6 H4350 and 140 AMAX. Just annealed 4x fired brass and the pockets are still tight. They were around 2780.

[gaijin]

No argument here.

I'd pursue your 43.5-44.1 as well.