VV N320 frustration with inconsistent powder drops

[rowdyb]

For a handful of reasons I'm switching from Titegroup to N320 for a 9mm minor load.

 

I dumped all the old TG out and replaced the powder measure assembly back on the tool head. Wiped down everything with lint free rag. New white plastic stop in the small powder bar spacer. New square plastic bushing where the crank rides on the powder bar. Return rod cranked down with a lot of pressure on the spring. This is on a RL1050.

 

N320 seems way less dense than TG and of a totally different shape. The setting that gave me 3.3 of TG yields about 2.1 of N320. It takes about two and a half turns and I'm at what equals 3.6 fo the VV powder.

 

I got the 3.6 using my small digital scale. I adjusted the knob while the powder bar was "out" after having dropped a charge in a case. I used 10 sized and primed cases of mixed head stamp where I tossed out the first three drops after making an adjustment. I drop ten charges in the ten sized and primed cases and the total equals 36.4 grains. So I assume this means I'm getting 3.6 per throw.

 

Well when I go to chrono in 20 rounds I'm getting an extreme spread of 80fps and seeing them from 820 to 900 fps. Uh, at 3.6 under a 147 grain plated bullet out of an Accu Shadow with the Aus barrel no way did I expect to see any at all sub minor. (yeah, read my match screw up post to see why i'm incredibly worried/sensitive about this now)

 

I could load TG staring off into space as fast or as slow as I wanted and I got a very consistent drop. My ES with TG is/was normally 20 or less fps. But the VV N320 doesn't seem to be as forgiving. Am I missing something in switching to this new powder? Is there a tip or trick I don't know?

 

I like the sound, the recoil, the fact my gun doesn't get so hot it heats up my holster and accuracy of my loads with the new powder but dang if it isn't killing my confidence seeing numbers go all over the place when I chrono. Heck, I even used a second chrono and it had the same variance as mine.

 

So, VV N320 experts in a 1050, what say you?

[rooster]

Even though I am using n320, it's not what is is all hyped about, at least for me anyway.  The accuracy in my g34 was at best average.  It meters great, and is exceptionally clean.  I had standard deviation in the 20's and 30's.  With TG I had a deviation of 6, and accuracy was better, and for a lot less money, however it ran hot and dirty.  Also wth n320 I was always at the fringe of max loading to make minor, with TG I had a little wiggle room.

[rowdyb]

With TG my gun got so hot it even made my holster very warm to touch. I'm pretty sure I even over heated a barrel in a gun with it......

 

The N320 doesn't do this crazy set my gun on fire heat. I get good accuracy in my gun with the VV. What I'm not getting is good numbers across the chrono....... and I'm hopefully right in my guess that it's related to a powder drop inconsistency and not something else.

 

(I sold a big amount of my TG supply to lay in a bunch of N320. i don't want to regret purchasing the 16# of a new powder....)

[B_RAD]

I too went from TG to N320, for the same reasons. 

 

I got 320 to meter very consistent.  

 

I agree with rooster. I didn't find it to be as accurate as TG.  I've since switched to Prima V for the same price as TG(maybe cheaper). 

 

Here's some chrono data I got with 135 plated. I know not the same Bullets you're using but my ES/SD was good. 

 

3.7 gr N320/135 gr Xtreme CZ SP-01 Shadow Orange

11/01/16 @ 11:40 am 

76 degrees 
Humidity 67 %
Chrono 10' from muzzle. 
Chrono in shade w/clear view to the sky and diffusers used. 

988
994
982
977
988
984
973
993
990
962 first shot

Hi 994
Lo 962
Av 983
Es 32 
Sd 9

 

 

I've got more chrono data (w/147's) at home but I'm pretty sure the ES/SD was similar. Weird that you're having the swings you are. 

[rowdyb]

So how/why do you think you metered it so well and I'm not? If I'm having metering issues with my 1050, what should I be looking at to trouble shoot things?

 

My powder level is about 1" above the bottom edge of the hopper. Too low?

 

I look and the powder bar goes all the way forward just before the handle is all the way down. When I lift up the bar goes all the way back. I'm not hearing or feeling any clunks or whatever that are new.

Edited April 10, 2017 by rowdyb

[Steve RA]

I'd give it a try with the measure loaded to the top and see how that works.

[ChuckS]

2 hours ago, rowdyb said:

 So I assume this means I'm getting 3.6 per throw.

Have you measured the individual loads to validate your assumption?

[B_RAD]

Rowdy, sorry man. I'm no help on why yours isn't throwing consistent. Though, I do load up towards the top like someone said. 

 

I also throw a lot then weigh, then adjust, then throw a lot of pulls, then weigh. Until I get it where I need it. 

 

After that, injust weigh to ensure it's still where I want it. 

 

Maybe load the hoper at leasr 3/4 of the way. Then do about 20 pulls to try and settle the powder.   Then pull on a separate, freshly sized case and weigh that. Then adjust for more or less powder and then do several more "settling" throws. Usually takes me around 20 mins to get mine where I want it when starting a new load.  

 

Prima V is especially bad about setttling at first. 

 

 

[rowdyb]

I've never used a powder other than TG in the past 4 years, so switching powders and setting my machine up to do so is new to me.

 

I did fill the hopper up to 3/4 full. With such a low mass powder I have a gut feeling this is important.

 

Chuck, I did just that next. I took two scale pans. (And put fresh batteries in the scale). So I weighed each one individually and then all together. Each one was 3.6 and the total of ten was 3.60.

 

So there ya go...... now to rechrono on Wednesday when the thunderstorms are done and see what's up.....

[ChuckS]

12 minutes ago, rowdyb said:

I've never used a powder other than TG in the past 4 years, so switching powders and setting my machine up to do so is new to me.

 

I did fill the hopper up to 3/4 full. With such a low mass powder I have a gut feeling this is important.

 

Chuck, I did just that next. I took two scale pans. (And put fresh batteries in the scale). So I weighed each one individually and then all together. Each one was 3.6 and the total of ten was 3.60.

 

So there ya go...... now to rechrono on Wednesday when the thunderstorms are done and see what's up.....

FWIW: did a test with the measure from full to almost empty (like 10 rounds of 7-ish grains of N340 remaining) and never saw any significant difference in charge weight. N340 has a similar shape as N320.

[SISIG]

I too have encountered the extreme spread with the newer N320. I thought it was the powder measure /scale and recalibrated and verified it again now it  measures consistently. But will have to Re chrono my load again.

 

 

[rooster]

My powder drop with 320 was always dead on.  I have a uniquetek micrometer powder measure and I could switch powders and then go back to my dial setting and it would be correct.  I never let my hopper go below 1/2 full.  Go back and recheck everything.  However with this said I still got all over deviations.  I went back to my notes and one time I had over 60 fps deviation in 5 rounds.

[rowdyb]

This is starting to sound like a VV issue and not a Dillon issue...

 

Mods can move this to 9mm reloading if they see fit.

[GrumpyOne]

Rowdy, try using the same headstamp of brass for your next trip to the chrono. TG is such a fast powder, I'm betting that a small difference in case volume doesn't really matter...but it might for N320.

 

As for my loads, last time I did a chrono check, my ES was 7, and the SD was 4...3.5 of N320 with a 147 home cast bullet, at 1.150...in a Shadow.

[rowdyb]

Thank you.

 

Taking the N320 out of the equation, I'd still like to know how others QC or trouble shoot stuff with their powder measure/bar/drop/bell crank etc etc. I have the manual but that's not really doing it for me.

[GrumpyOne]

99% of them come here and ask....

[ChuckS]

30 minutes ago, rowdyb said:

Thank you.

 

Taking the N320 out of the equation, I'd still like to know how others QC or trouble shoot stuff with their powder measure/bar/drop/bell crank etc etc. I have the manual but that's not really doing it for me.

Out of curiosity, what dies are you using?

 

[RGinIdaho]

I've found that metering(within reason) is not as critical as getting the powder into its proper pressure range. My notes show single digit sd's with N320 and 125's at 4.2 and 4.3gr. Below 4.2 with 125's I was in the low 20's for SD.
 

I get single digit SD's with thrown charges and mixed brass with several different powder/bullet wt. combos. Just have to find the right charge.

 

Sounds like you are getting consistent throws at 3.6gr. Maybe the powder would do better at a higher or lower pressure range?

[rowdyb]

dillon dies for size/deprime and swage and the Redding Pro seating die and a Lee Factory Crimp die. Mr Bullet Feeder powder funnel/expander.

 

i'm really curious if what was needed at an initial powder change over was the need for a fuller hopper and enough movement/loading for the low mass powder to settle more.

 

most people are telling me they're making 130pf with 3.4 of n320 and a 147 plated. if i don't have to use 3.6 i don't want to.....

Edited April 11, 2017 by rowdyb

[ChuckS]

Just now, rowdyb said:

dillon dies for size/deprime and swage and the Redding Pro seating die and a Lee Factory Crimp die. Mr Bullet Feeder powder funnel/expander.

Try a standard crimp die and see if your SD tightens up...

[rowdyb]

that's an easy enough switch.

[GrumpyOne]

Forgot to mention...I'm at a 134 PF with 3.5 of N320.

[MemphisMechanic]

12 hours ago, rowdyb said:

that's an easy enough switch.

 

You can also adjust the FCD to behave like a traditional crimp die. Run the neck-crimping part down and thread the die body out to return it to the same "barely straightens the belling back out" setting it was at beforehand.

 

But for simplicity's sake if you have the factory Dillon die around, I'd just install that.

[rowdyb]

so why no love for the lee fcd and its possible effects on why i'm seeing wild velocity swings with n320?

[pjb45]

I use vv320 exclusively on my 1050.  I change out the powder drop to a micro.  It is true I do get some slight variations sometimes.  But over the course of multiple 3 round chrono strings it is pretty consistent.  I mean for years.

So unless you are a bench rest shooter with a trickle drop live with the variations.

 

I kept probably 20 different chrono results from Area and National matches and the variance was usually less than 1 power factor all things equal.

 

All things equal because during a very cold Nationals in Tulsa the PF drop while the next day was warmer and a different match the PF was back at the expect PF.

 

VV320 is a great powder and very consistent for me.