6 Dasher - Load selection

[Redfoxcreed]

I have a tricky question for you guys.

first disclaimer, I know my sample is small but it’s all I have for the limited time I have.

contexte.
My Dasher load was 30.97gr N150 w/109’s Berger in Alpha brass standard pre-OCD. It’s pushing 2815 +-

Now new Alpha brass but the OCD now. Neck tension is higher 0.003/0.0035 and internal volume is a tiny bit higher ( 40.52 va 40.61)

The same 30.97gr is pushing 2820 fps with untouched brass and 2810/2813 fps with expanded neck (0.0015/0.002) and SD’s are not so great anymore ( 9 to 11 fps)

Today’s I’ve tested 30.91 and 31gr .

untouched brass 30.91gr - 2819 fps
SD:4 fps ES:10
Reference picture shot #1 is my cold bore shot

Expanded neck 31gr - 2819 fps
SD:7 fps
ES:16 fps

Reference picture shot #5 is potentially a flyer as I was telling myself to not screw up

knowing it’s a really limited sample and results what would you pick for the OCD brass ?
30.91 or 31gr?

I don’t have time to go back to the range before the match…

 

[Henryrifle]

@Redfoxcreed: Impossible to say given the small sample size as you stated. I will say that the velocity, ~2815 FPS is really slow for a dasher even with a 109. That's straight 6BR speed. You could easily be on a scatter node as there is almost no difference between 30.91 and 31 grains (0.29% change). On my scale I would barely even be able to measure that difference.

If you know shot 5 was a good shot on the 31 grain target then I'd find another few moments to go test a few 3 shot groups with higher charges. If you can't do that then pick the best SD and roll the dice.

Just my opinion...

Henryrifle

 

[Redfoxcreed]

@Redfoxcreed: Impossible to say given the small sample size as you stated. I will say that the velocity, ~2815 FPS is really slow for a dasher even with a 109. That's straight 6BR speed. You could easily be on a scatter node as there is almost no difference between 30.91 and 31 grains (0.29% change). On my scale I would barely even be able to measure that difference.

If you know shot 5 was a good shot on the 31 grain target then I'd find another few moments to go test a few 3 shot groups with higher charges. If you can't do that then pick the best SD and roll the dice.

Just my opinion...

Henryrifle

The only thing I disagree on is the speed/ pressure. I’ve tested that combo with my pressure trace and it’s averaging 58kpsi so it’s not an hot load but definitely not a low pressure one.

I’d like to test Varget and 4166 but I’m too late.

I wish I had more time but sadly

 

[WIB3]

First of al ignore all of the SD and Ed that you are working with, look at groups they don’t lie. We live in a world of information that not always correct. Go by what your rifle is telling you and not by a program. Dashers love 103 to 105 class bullets, it’s been proven, a 103 VT at 3000ish is hard to beat.

 

[johara1]

Very low velocity , Is that the only powder and bullets you have? Varget and RL-15 also H4895 you can go as high as 3100 with a 105 or a 103 but they seem to shoot best at 3000 or a little less.
BTW what primer are you using? ..... jim

 

[4isnaf]

Redfoxcreed,

Earlier, I posted on your other thread on the subject because I'm hoping to run N150 in 6 dasher.

I'm really interested to get more infos about the pressure you're seeing at the speeds you're getting. How does the brass look like? Does it match what your strain gauge system is telling you?

Did you up the powder charge until you get actual pressure signs on the brass? I'm asking because, on your other thread, you're saying you get carbon on the shoulder. I would interpret it as a Low pressure sign, unless the brass is telling you otherwise.

I don't want to bash on your system or anything. I'm just thinking maybe its off...

Anyway, thanks for sharing your results.

Naf