6.5 Creed N160 Velocity Stall

[diemaco]

I loaded up a bunch of Norma brass with 129gr ABLR bullets and N160 powder in 0.3gr increments. For 6 or so loads in a row, the velocity more or less stalled and slowly crept up ~100fps. Then the last couple of loads (up at max of 44gr) it shot up another 150 fps quickly. No pressure signs noticed, and I was still well below book velocities (although my superlite only has a 20" barrel).

Was I starting to see pressures spike? Do I try a few slightly higher loads and see if things settle down or I see signs of excess pressure?

Has anyone else experienced this with N160? Any insights to this powder, as it's new to me. I'm sick of not being able to find 4350 and 4831 so I figured I'd branch out.

 

[chrismc]

Might be a tad slow for your combo. VV550 or 555 or 6.5 Staball may get you the velocity you want.

 

[R005t3r]

6.5CM
136gr. Lapua Scenar on Lapua brass, 2.8" OAL
41.5gr 6.5 StaBall
FGMM Magnum primer
24" barrel on a T3X action
+2800 FPS

 

[Dylan4570]

Velocity/Pressure often isn't linear as you approach a compressed load.

 

[boxhitch]

powder measure to velocity often is not linear through the entire range either, for any powder
Larger spikes would be more indicative of a limit
more testing

and more measuring...... pressure signs can show in various ways

 

[todbartell]

129gr ABLR bullets and N160 powder in 0.3gr increments. For 6 or so loads in a row, the velocity more or less stalled and slowly crept up ~100fps. Then the last couple of loads (up at max of 44gr) it shot up another 150 fps quickly. No pressure signs noticed, and I was still well below book velocities (although my superlite only has a 20" barrel).

How many rounds did you fire at each increment?

 

[diemaco]

3 rounds at each interval. I know not statistically significant, but I was mostly looking for pressure signs, velocity, and if that bullet/powder combination showed promise.

 

[diemaco]

Velocity/Pressure often isn't linear as you approach a compressed load.

Maybe that's the key. Last couple loads were compressed.

 

[todbartell]

3 is better than 1! Sometimes apparent plateaus in velocity and then a spike is just case capacity demons and very small sample size playing with a guys head

 

[diemaco]

3 is better than 1! Sometimes apparent plateaus in velocity and then a spike is just case capacity demons and very small sample size playing with a guys head

It could be that too . I suspect the sudden proliferation of easy to use chronographs means a lot of people will be in the same boat.