JARACAL

Goeie dag almal

Is iemand dalk bereid om te help met n QL berekening asb? Ek is opsoek na n node...

260 Remington 1-8 twist

VV N550
Titan .264 130gr EXBT

Looplengte: 601mm
Dop lengte: 51.45mm
Dop volume: 53.4gr

Totale lengte: 71.00m

Baie dankie by voorbaat

Willem

Without having measured velocities we can not calibrate your powder burn rate here, but here is a chart to guide you,
Your highest achievable node ( WITH DEFAULT BURN RATE) is predicted to be around 2804 fps and your lower pressure node is predicted to be around 2686 fps

Hi Dale

Thank you, this is what I have up to now after 5 shot groups. My concern is that the bullets tumble.

39.8gr, avarage 2739ft/s, ES 24.
40.0gr, avarage 2762ft/s, ES 25.
40.2gr, avarage 2770ft/s, ES 27
40.4gr, avarage 2815ft/s, ES 36
40.6gr, avarage 2824ft/s (chrony was not great on this one)

The bullets does not stabilize at lower loads, the bullets were tumbling when hitting the target, sideways impact....
The best I managed to get was 3 out of 5 bullets not tumbling on the 40.6gr load.
Am I doing something wrong or will this be a case of my rifle does not like these particular bullets?

I managed a 0.55 MOA group with 140gr Nosler Accubonds, and a 0.45 MOA group with Sierra Matchkings.

I would have liked to use the Titan bullets, they perform fantastic on my 30-06.

Thanks for helping.

Willem

You have useable case capacity indicated as 44.485gr H2O?
Is this the same as my 54.3gr H2O case volume?

Based on your chrony readings above your 40.4 grain load should have shown some potential.
I do note that there is a rather large non linear increase in your velocity between 40.2 grains and 40.4 grains.
Are you sure your chrony is accurate ?
The Titan bullets are a mono brass alloy and are very long for their weight. but with a 1 in 8 twist they should be stabilizing in your rifle.
The 130 grain would also not stabilize in my 6.5 x 55 with 1 in 8.75 twist.
My suggestion would be to try the 114 or 120 grain.
I must agree with you about their terminal performance though. A real drop on the spot dead right there bullet.

Whisky17 wrote: Tue Oct 10, 2023 9:34 pm You have useable case capacity indicated as 44.485gr H2O?
Is this the same as my 54.3gr H2O case volume?

Useable case capacity is the case capacity minus the capacity that the bullet is taking up when seated to your stated COL.
In other words the bullet is taking up about 10 grains of the measured case capacity.

Thank you for the reply. I am really surprised that the bullets did not stabilize.

I did shoot a load with the 120gr EXBT, the grouping was 3 inches, avarage 3021ft/s and ES 29 with a load of 42.8 gr.
I mentioned that my calculations with the Nolser and Sierra was really close, so I am of the opinion that my rifle does not like the Titans.

I hope the Nosler bullets does not cause too much meat damage...

Thanks again for your input.