9 minor N320 load

[tomv]

I'm looking for a clean 9 minor load for falling steel. I have a good supply of N320 powder so I tried 4.4 gr of that under a 115 gr Montana Gold JHP @1.142 COAL. This is the maximum charge weight from Vihtavouri load data. The ammo chronoed @ 125 PF which is way below the 136,600 predicted by their data. I used my STI DVC open gun to shoot over the chrono. Viht data is for 4" uncompensated barrel and DVC open is 5" compensated.

The ammo cycles in both my DVC open and DVC steel guns but the empties just dribble out of the guns and the slide wont lock back on the last round on either of them.

I bumped the powder up to 4.6 gr and will try that tomorrow. Before I go through the process of bumping the charge up a little at a time and checking for pressure signs as I go I'm curious about others experience using this powder / bullet combination. How far over Viht. max recommendation are people running?

[Miggz55]

I'm looking for a clean 9 minor load for falling steel. I have a good supply of N320 powder so I tried 4.4 gr of that under a 115 gr Montana Gold JHP @1.142 COAL. This is the maximum charge weight from Vihtavouri load data. The ammo chronoed @ 125 PF which is way below the 136,600 predicted by their data. I used my STI DVC open gun to shoot over the chrono. Viht data is for 4" uncompensated barrel and DVC open is 5" compensated.
The ammo cycles in both my DVC open and DVC steel guns but the empties just dribble out of the guns and the slide wont lock back on the last round on either of them.
I bumped the powder up to 4.6 gr and will try that tomorrow. Before I go through the process of bumping the charge up a little at a time and checking for pressure signs as I go I'm curious about others experience using this powder / bullet combination. How far over Viht. max recommendation are people running?

Shorten your OAL?


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[muncie21]

I don't have any data for that particular weight bullet, as my reloads for 9mm start at 124gr. 

 

With 124gr coated lead (Bayou or BBI) fired from a CZ SP01 I'm seeing around 1080-1100fps, or ~130-132PF.  This is with 4gr of N320 and OAL of 1.080-1.090.  I load these (and my 135 gr bullets) short because of the CZs short'ish throat.  Comparing my results to the VV load data, my velocities are on target with their data, and the loads are very close to published max (4.0 versus max of 4.1, depending upon bullet).  I did not however, notice any signs of over pressure. 

[CZ85Combat]

4.0gr with 124MG jhp @1.110 132pf CZ Shadow

[open17]

3.4 N320 with a Bayou 147 coated, 3.7 N320 with a 147 Montana Gold CMJ.   1.145 OAL.

Makes 130-135 pf in 9 different guns.  Never tried it with a 115 or 124.  

[zzt]

Use a slower powder.  Firing a recipe designed for a 'normal' pistol through one equipped with a comp will almost always result in lower velocity that expected.  Switch to something like N340 and your results will improve.

[ltdmstr]

As zzt stated, use a slower powder.  Rule of thumb is fast powder for limited gun (no comp) and slow powder for open gun (w/comp).  If you want to stick with VV,  I would try 3N37 or N350.  The slow burn rate will help get your velocity up and improve the performance of your compensator.

[jliew08]

Just got an open pistol myself and chrono'd my production load of 3.4 VVn320 through it.  Through a Glock 34 it chrono's at 130pf, my open gun chrono'd that load at 125pf.

 

I will be coming up with a falling steel load soon.  I have been testing HS-6 or Silhouette to make major so I think I will just drop those charges a bit and see where I'm at.  My understanding is you still want enough gas to work the comp for a minor load.  I don't think N320 is going to be the ticket as others have stated due to it being a faster burning powder.

[zzt]

j, WAC, Silhouette and HS-6 in that order (burn rate).  A lot of Open SC shooters are using WAC in the 5.0 to 5.4 range with 115gr HAPs.  That's well below Major, and well above 125PF.  It works.  Gun shoots flat and the dot doesn't move much.  A touch more with Silhouette and probably a grain more with HS-6.  My fav is Silhouette.