BH209 Lot to lot velocity test

[ElDiablo]

Thanks again Encore! Small sample size but very interesting that a 1.5 grain weight charge difference between lots 37 and 41 only resulted in a 28 fps average velocity difference.

Looks to me like velocity difference is minimal between lots when measured by volume (as it was with weighed charges).

I’ll be curious to hear how you and others interpret the data….

 

[ENCORE50A]

................ I’ll be curious to hear how you and others interpret the data….

Not to sure yet how I'll finalize my interpretation of this. Just finished cleaning up DUNAMIS, washed up and back online. I'll be looking closer at it.

My instincts tell me a couple things. Lot #37 has more deviations than lots 39 and 41.
Lot #41 data has been puzzling, yet it appears to be as consistent as Lot 39.
Lot 39, IMO, at least until I shoot more lot41, is a very good lot of propellant.

You're shorting yourself velocity by not averaging volume to weight.

Side note;;;;;;;;;;;;;; boy am I going to like that new hunting charge

 

[CatamountRob]

I’ve looked at the 2 charts a half dozen times and I’m still not sure how to take it.
I kept hoping someone would break it all down for me.
Was the shot to shot consistency better when measured by volume?

 

[ENCORE50A]

The shot consistency was better when measured by volume, throwing 10 charges, weighing all 10 and then averaging the weight.... bottom chart.
It appears the heavier charges are much more stable??? Example: Again do not use the data but, notice my hunting charge printed in red.

 

[CatamountRob]

Pretty interesting. I’ve always felt that as long as you were consistent in your technique, measuring by volume was perfectly adequate for 99% of users.

 

[45-70]

The point would be to attempt to determine if there is a significant difference in velocities between lots using the method the majority of us use to measure charges (by volume).

We know that BH209 particle size has been changing and/or getting denser per unit of volume. It seems that Encore has established with this test that the weight of the powder charge relates directly to velocity. It would follow that, for example, 120 grains by volume of various lots would produce different charge weights and thus different velocities. But I haven’t seen anyone actually test this.

I think the best next test protocol would be to weigh and average 10 volume-measured charges per lot and then use that weight for each lot to conduct the velocity testing.

It’s worth remembering that with BH209 there is no real variance in grain size within a given bottle (fines) like there is other subs. Differences in measures and measuring techniques is of course a reality but wouldn’t factor into this test. We’re just looking to determine how much velocity difference one might expect with a given volume-measured charge between lots with all else being equal.

I think some where Bestill suggested that