N320/ MG 180gr sanity check

[blue edge]

Well... the 4.8gr didn't run well. I put 50 through the gun and it didn't feel right and about 8 of them failed to go to battery. Working on that problem now....

http://www.brianenos.com/forums/index.php?...pid=859995&

May be a DUMB question, BUT did you chamber check ALL of your test rounds? At 4.8 1.185 mine makes MAJOR and RUNS till the cows come home!!!!!!

guess what the cows have not come home YET and the gun is still RUNNING!!!!!!!!!

Kevin

[Seth]

mmm..........now I know what the fuss is all about. 5.2gr is just SWEET. No pressure signs at ALL in the brass. I can't explain what I like about it... but I like it! Its cleaner than my Univ. Clays load, and a lot less percussive.

The gun ran much better with it. No battery issues once I replaced the recoil spring.

S.

[BNorth]

Seth,

I'm running 5.1 at 1.205" and Precision Delta bullets in my Edge with factory barrel. I made 166 at Area 8 and 167 at Summer blast last year.

I've since started using Zero JHP and reduced the OAL to 1.900". I haven't had a chance to run them over the Chrono yet.

Bob

[Seth]

Thanks Bob. I'm close, for sure. I have 300 rounds of the 5.2 load ready to go the range tomorrow to double check function. Once I'm completely certain it works, I'll chrono and see where I'm at.

S.

[Jim Norman]

"U" Die on all brass, solves MOST out of battery probs.

I run 1.18 5.0 with Precision Delta 180s, Get around 171 PF.

I noticied I was starting to need to increase my load last year. Got up to 5.3 and decided a new barrel was in order. Load now back where it should be.

Jim

[Seth]

Jim,

I don't need to u-die. All of my .40 brass has been roll sized. I haven't had a round that failed the case gauge.

It seems that the recoil spring was shot, as a change back to the original 14# spring solved ALL battery problems.

Thanks for the info. I'l get chrono'd asap.

Seth

[Seth]

Update:

This is a GREAT load. I've run about 500 rounds of the 5.0gr at 1.185" and its soft and clean. The gun cycles great with it, and aside from the initial problems has proven itself to be reliable and accurate.

Its a joy to clean up too! Very clean.

[SteveU]

Update:

This is a GREAT load. I've run about 500 rounds of the 5.0gr at 1.185" and its soft and clean. The gun cycles great with it, and aside from the initial problems has proven itself to be reliable and accurate.

Its a joy to clean up too! Very clean.

Yep. That's the one. Join the club.

[Seth]

I FINALLY got around to chrono. 5.2 JUST made major at 165pf. 5.0-5.1 turned in a consistent 909fps at 164 pf. Outdoor temp at about 30*.

Is it better to reduce the COL to 1.170 at leave the powder drop or bump the powder charge? The gun will feed anything, so I don't care.

S.

[pjb45]

vv320 is sensitive to temperature. A couple of years ago I chrono'd some rounds in cold weather, then the next day it warmed up and the power factor increase. At this year's Nationals, the exact same load, same barrel condition, same chrono guys, two different days had a difference of ~ 6 PF solely due to the temperature.

I generally run 1.19, 4.88-4.90 gr of vv320, MG 180, Nowlin barrel and it comes in around 171-172. Using 180 Zeros produces the same results out both the Nowlin and Kart barrels.

Two years ago, Taran was working up a load just before SS Nationals, his Schuemann always ran 10-15 fps slower than my Kart.

Over 5 National Matches, 3 A2 Matches and 3 WSSSC- 1.19, 4.88 and 180 JHP have produce at 170-172 pf out of either the Nowlin or Kart barrels. The outside temperatures ( except for last year's Nats) have all be moderate.

The National chrono guys told me the single one thing you can do to get the most accurate reading this side of using lights is to put a blast shield in front of your first screen. Sunlight seems to produce slower times than a light box.

Personally, I think 5.2 is going to be way to high when your temperatures warm up a bit.

[Seth]

Paul,

Its supposed to be 20* plus warmer tomorrow and I'm going to try and chrono again. I have about a 1/2 dozen baggies made of of different combos and hopefully I can find one that is honestly major. I will plan to revisit it once the weathers in the 70s.

I appreciate your insight.

Edited January 29, 2009 by Seth

[kgunz11]

Mine has not varied from 90* + to 40* more than 1pf using VV N320

[trickpony]

I've got a few STI/SVI guns and I use N320 with MG 180 gr. JHP's loaded out to an OAL of 1.135" - 4.7 grains in my Schuemann Ultimatch guns is 173pf and 5.3 grains in my Infinity barrels is 172 pf.

[Seth]

More Data:

GR OAL PF

5.4 1.170 179.082

5.3 1.185 171.792

5.2 1.185 169.848

5.0 1.185 162.198

Indoors using IR screens on CED M2. Ambient Temp 28*.

Edited February 6, 2009 by Seth

[G-ManBart]

5.3 1.185 171.792

That looks like a winner to me. You won't be able to see the difference between that and the 169.8pf load and it'll give you plenty of margin for error. My Open load that has been 171-172pf everywhere under pretty varied different conditions went 166.1pf at Nationals.

[Seth]

That's the plan. Do you think there will be any statistically relevant deviation due to temp? It was f-in cold in there and any match with a Chrono will be 90+.

[G-ManBart]

That's the plan. Do you think there will be any statistically relevant deviation due to temp? It was f-in cold in there and any match with a Chrono will be 90+.

I haven't done nearly as much testing as some folks have done, but my experience has shown N320 to be pretty temp neutral with maybe a little bit of positive tendancy, but not much.

Last year I got my Trojan only a couple of months before the WSSSC so I had to do some chrono work and make sure I had a load that would run. The one I settled on chronographed at 938fps here at 6,500ft above sea level on a sunny 32*F day. When I chrono'd at the match in Mesa it was 65*F and through their chrono box. The average was 940fps....close enough for government work. The difference between sunny outdoors and an indoor chrono box, a couple thousand feet of elevation and 33*F difference in temp either cancelled each other out, or didn't factor into it at all.

I'd still check your load as it warms up, but wouldn't bother doing it until you get something like 20-30* difference in ambient temp. Chrono at the same place with the same setup and the only variable should be temp. I'd expect you might see a slight increase, but even then it'll take a decent sample size to know if it's the temp or just a coincidence. Even running ten or twenty rounds over a chrono still leaves some uncertainty. Minimum I'll use ten readings, but I prefer to get 20 and repeat the test over a couple of days just to be certain. R,

[Seth]

Any info on Minor with the same ingredients? I am shooting a steel match this weekend.

[kgunz11]

4.2 gr of N320 is pretty soft behind the 180.

[Seth]

Any idea on PF?

[kgunz11]

Nope. Just know it's not major, but it should make the minor floor. In my Edge, 4.8 is 160pf, 4.9 is 164, 5.0 is 167, 5.1 is 169. So if you use that as a guide you can theorize that 4.7 is 157, 4.6 is 154, 4.5 is 151, 4.4 is 148, 4.3 is 145, and 4.2 would be 142 or so. I would think that the way the pressure curve works on the VV N320 though that 4.2 is much lower than 142pf. When pressures start to build they rise quicker but as the taper off to the slower side they drop more substantially. Load some at 4.2 and chrono them and compare them to your current major load and let us know what you find out.

[Seth]

I kind of used the same fuzzy logic. I will chrono Thursday to see if it works. The gun is now sprung down to 9# with the bushing barrel in it. I'm thinking if this works, I'll make a couple of thousand of them and have my IDPA load.

[RePete]

Any idea on PF?

4.6gr/N320 under a Frontier CMJ gives me a PF of 170 through both the G35 and the STI Trojan.

[Seth]

But at what length? I'm seeing 170pf with 5.3gr at 1.180"

[RePete]

But at what length? I'm seeing 170pf with 5.3gr at 1.180"

1.125"