19 replies to this topic

[mizer67]

Stupid question, but I'm barely making minor PF with a FS 4.25" M&P 9mm, 124 gr Montana Golds and 4.3 grains of N320 at 1.138" OAL.

Went as high as 4.4 grains (4.3 is VVs max load) and still was barely making 130 PF and velocity wasn't at all consistent, ES was 69 fps out of 40 rounds, and I had three rounds still fail to make minor. I weighed each charge, and I don't believe it's powder measure or scale related.

My thrown Tightgroup loads have no trouble with consistency or velocity. I don't want to push this N320 load too much farther, but it seems like I need a couple more tenths to make it safely above the minor PF floor.

Anyone have a similar experience with a slow jug of N320?

[gng4life]

I haven't loaded it yet with 124's but with the MG 95 JHP, I had to push it to make minor. I wasn't getting the ES like that but it took a bit to make it. They don't list a 95gr bullet in the VV manual but for the 90 and 100, they list 5.3 and 5.1 as max. I had to push it to 5.7 to get it about 133 PF. That was out of a 4.25" STI. No pressure signs at all with that load and it was very mild and extremely accurate.

I forgot to add: it was not inconsistent or slow, this is the same for several 4lb jugs I had.

Edited by gng4life, 06 August 2011 - 06:39 PM.

[GSWEAR]

I've never heard of a slow lot of VV powder, they are generally very consistant lot to lot but anything is possible.
I run 4.1 N320 and 124MG JHP and it makes year round in a 4 1/4" M&P with a KKM barrel and a M&P Pro, 4.0 will make pf but gets close in cold weather.
I've shot around 8 or 10K of this load and used a couple different lots with no issue.
Interested in what others have to say.

Greg

[Sarge]

In my experience stock M&P barrels are slow. Combine that with MG which are slow as well and you end up with these situations. I had to run loads off the charts to make a comfortable PF with the 9PRO I had now I make 135 with 4.1 N320 @1.13 out of my G34.

I agree that Vit powders are pretty consistent from jug to jug but I guess it is possible. Up the charge a tad and look for pressure signs. I'm sure you wont see any with N320 but look for them just the same.

[RH45]

A friend of mine shot his 5" STI Spartan at the state IDPA match yesterday, and the chrono showed 127pf. He was running the "new" Zero, 125 grain, conical, jhp, with 4.2 grains of 320, and a CCI primer at 1.135 OAL.

My load chronoed 130.5pf, out of my M&P Pro (5"). I was running 4.2 grains of 320, with a federal primer, with a Zero, 125 grain, jhp, .356, .38 super bullet, with OAL of 1.12.

I've always had slower readings at the chrono with MG bullets, over Zeros, in the pistols I've tried them in.

[windscreen]

The Spartan load was actually 1.145" (but you had a pretty good memory on the rest )

Over my CED chrono in the same temps, in the shade (but no coffin) that load made 132 PF.

-Steve

[Red Ryder]

I am getting 133 PF (using a coffin at a major match) with 4.2 grains of VV N320, 124 grain MG CMJ, loaded out to 1.150, with RP brass and Federal spp, with an XDM 4.5 inch barrel. I can't imagine that a M&P is that much slower.

[1SOW]

CZ75B-4.72" bbl: I've been using n320 for several years. With the Zero 125JHP, 4.0 @ 1.10" shows 132pf over a CED chrono.

With the 124 MG cmj, 4.1grs gives about the same @ 1.132" (:-)

Maybe your jug, but I've gone through lots of jugs with no noticeable changes. The powder is very boring in the South TX climate.

Edited to add: Fed spp, WIN brass (if it makes a difference)

Edited by 1SOW, 08 August 2011 - 08:50 PM.

[Loop51]

In my experience stock M&P barrels are slow. Combine that with MG which are slow as well and you end up with these situations. I had to run loads off the charts to make a comfortable PF with the 9PRO I had now I make 135 with 4.1 N320 @1.13 out of my G34.

I agree that Vit powders are pretty consistent from jug to jug but I guess it is possible. Up the charge a tad and look for pressure signs. I'm sure you wont see any with N320 but look for them just the same.

I am getting 133 PF (using a coffin at a major match) with 4.2 grains of VV N320, 124 grain MG CMJ, loaded out to 1.150, with RP brass and Federal spp, with an XDM 4.5 inch barrel. I can't imagine that a M&P is that much slower.

How sensitive to temp is N320? I am running 4.2gn of N320 over a MG 124JHP @ 1.140" in a G34. I chrono'ed that load yesterday (temp was around 92, heat index was over 100) and 10 shot average PF was 128 for the first 10, 129 for the 2nd and 129 for the 3rd group.

That seems low to me. I saw velocities as low as 1007 fps and as high as 1055. I expected that load to be in the 130-132PF out of the G34.

[Sarge]

My limited testing showed 320 to be virtually immune to temperature changes. Always 134-135 no matter the temp, humidity, elevation, etc.

You could have a slow jug or getting bad readings from the chrono. Put in fresh batteries. Then blacken the MG bullets with a sharpie and see if anything changes.

[Loop51]

My limited testing showed 320 to be virtually immune to temperature changes. Always 134-135 no matter the temp, humidity, elevation, etc.

You could have a slow jug or getting bad readings from the chrono. Put in fresh batteries. Then blacken the MG bullets with a sharpie and see if anything changes.

I think it may be the chrono...I have used this same jug to load 147gn Zero's and they were VERY consistent. I have to ask the stupid question though, whats the point in marking them with a sharpie? lol

[CBags04]

My limited testing showed 320 to be virtually immune to temperature changes. Always 134-135 no matter the temp, humidity, elevation, etc.

You could have a slow jug or getting bad readings from the chrono. Put in fresh batteries. Then blacken the MG bullets with a sharpie and see if anything changes.

I think it may be the chrono...I have used this same jug to load 147gn Zero's and they were VERY consistent. I have to ask the stupid question though, whats the point in marking them with a sharpie? lol

So the bullets contrast more against the screen.

[Loop51]

My limited testing showed 320 to be virtually immune to temperature changes. Always 134-135 no matter the temp, humidity, elevation, etc.

You could have a slow jug or getting bad readings from the chrono. Put in fresh batteries. Then blacken the MG bullets with a sharpie and see if anything changes.

I think it may be the chrono...I have used this same jug to load 147gn Zero's and they were VERY consistent. I have to ask the stupid question though, whats the point in marking them with a sharpie? lol

So the bullets contrast more against the screen.

Learn something everyday...

[mizer67]

I don't think it's the chrono, but will try changing batteries.

I say this because I ran 100 rounds of my 4.2 gr Tightgroup 124 gr MG load at 1.138" OAL over my chrono the same day I did the N320 load tests, and got an avg. velocity of 1,103 fps, with a SD of ~6.7 and ES of 32. It was reading those rounds, and they're about where I would expect them to be, velocity wise.

[CocoBolo]

There is a preponderence of evidence that indicates that something is either wrong wtih your load or your gun, or you bought some "immatators powder", there could always have been a mistake at the packager.

Take the scientific approach:

1. Verify that your powder scale is accurate, by checking it against one or more scales of a different type. (electronic vs beam)
2. Now that you have verified the weight load 10 for testing.
3. Verify the diameter and weight of the Montana gold bullets.

It is good that you have some loads that you can use for a sanity check however shoot those over the crono in the same session that you crono the suspect N320 loads.

By the way getting titegroup to Crono the same PF twice is like a miracle, it has to be the same temprature. It is reverse temp sensative to the extreme.

Locally 3 of us shoot MTG's in CZ Shadows at 135 pf with 4.0gr of N320. We all bought our N320 from different places, Grafs, Powder Valley, and one local at different times of the year, consistent results across the board.

It could be like one of my open guns it always shot 170pf, then one day I crono and it was 160pf, so I started adding more and more and more powder and could not get to 170pf. Tried the loads in another gun 200 pf. Yep, the barrel got just worn enough the gas was going around the bullet. If I had been smarter then I would have switched to .356 bullets and kept running it.

[mizer67]

Where I live in FL, this time of year, the temp. never varies by more than a few degrees for a high, and rarely more than 15 degrees between high and low temps, so temp sensitivity is not a major concern as I haven't yet progressed to travelling beyond local matches.

I received the N320 from Powder Valley recently. It's unlikely it's fake.

MGs 124 CMJs weigh spot on 124 grains for the 10 I sampled. Diameter is also fine.

I gave away my old scale recently to a new reloader I'm teaching, but the checkweights weigh as they should.

Thanks for the help, though, CoCo, and everyone. Guess I'll keep working on a load. Maybe this powder will be better in my .40s.

[Sin-ster]

Slight necro-thread...

I run a very similar mixture of components as the OP-- 124 grain MG JHPs, and N320. I made power factor SUPER comfortably in my G17 with 4.2 grains @ 1.155, cruising to 131 PF in a coffin.

When I got my 9 Pro, I started with 3.9 grains just to work up to it; I was also loading to 1.140, as I am now. Long story short-- it SEEMED like the 5" barrel was getting notably more velocity.

But looks can be deceiving...

I ended up with 4.1 grains @ 1.140 for the 9 Pro, and had an even more comfortable PF of 132. Turns out the lot of N320 I had was... hot. Must have been. Only thing that makes sense.

I took the exact same cartridges that tested in the coffin @ 131 and ran them through the same G17, that hadn't been shot since to verify my chrony. Sure enough, spot on with where it had been before-- 130 PF across 25 rounds. ES, SD, Average, Hi, Lo-- almost identical.

I then ran my newest lot of N320 over the same chrony, with the previously mentioned load. 126 PF. Eek. I upped the charge to 4.2 and tried it again; 128 PF. Not good enough.

Baffled, I ran both the 4.1 and 4.2 load @ 1.140 through the G17. 129 and 132 PF, respectively.

IOW, the hot lot of powder aside (it did not come from my usual source, and who knows how it had been stored), my experience correlates with the OPs, almost to a T. MG may be "slow", as some have noted-- but the 1:16 twist barrel in the M&P is slow for sure.

4.3 incoming-- very, very carefully. I don't anticipate problems, and I'm running Federal SPP-- so if there's any over pressure, it should be obvious. We shall see...

[Sin-ster]

Whelp, 4.3 without a problem-- although I can tell it's getting close the hairy edge, at least according to the soft Federal SPP. No flattening or smudges, but I'm starting to see the occasional tool mark from the breach face.

131 PF across 30 rounds; 4.3 grains N320, MG 124 JHP, 1.140 COAL.

I had some at 4.275-ish (measured across 10 throws) that were 130 on the nose; leaving my powder hopper set there, for the sake of the occasional bridged charge.

[Tul9033]

Here's my results:
124gr MG JHP
4.2 VV N320
1.12 OAL
S&W 5" M&P Pro
130.1 PF

While I found VV to be super consistent and accurate it just wasn't putting out the power. Wasn't noticeably cleaner than TG. Costing twice as much and being a stick powder which metered OK I've decided to switch back to Titegroup.

[recoilguy]

I got a 132PF with a CZ SP-01 Tac using

MG 124 FMJ
4.1 VV N320
AOL 1.123
Fed SSP

I am very happy with this load. I have not Chrono ed any other loads of mine. I should really compare but since I have settled on the described load I have shot almost all my other loads and have only reloaded to this recipe. I should recheck my results soon because I am now on a different jug and it appears there may be some variation. Although I went away from TG to VV N320 because I was told there would be very little if any. The price diffence ammoritized over 1700 rounds / pound is so minor it is barely a factor at all. Interesting reading about the different results in the different guns.

RCG

Edited by recoilguy, 23 March 2012 - 01:35 PM.