Viht N555 Guidance

[Long Cut]

Newer reloaded here and unfortunately due to the times, the ONLY powder I could find anywhere was Viht N555.

Due to Viht N555 being a new powder, Viht has very little reloading data available on their website. I’m going to follow their Min-Max chart BUT the ONLY N555 data for 140gr bullets is for Berger Hybrid Target 140’s.

My question is, will Viht’s N555 chart for Berger Hybrid 140’s work with my Nosler BT 140’s since they’re different styles of bullets?

I’ll be using this to reload my 6.5 Creedmoor.

My setup is as follows,

Lapua SP Brass - trimmed to 1.909”
CCI 400’s (only I could find)
140gr Nosler BT
Viht N555

I’m intending on loading 40-40.5g @ COL 2.717”, does this sound like a reasonable start?


Viht’s Min/Max for 140g Berger Hybrid Target bullets is 40.1g MIN & 43.4g MAX for reference. COL 2.717” for reference.

 

[spife7980]

It’ll be close enough to start with. The difference will be about the same as if you were using brass on two different ends of the volume spectrum but “start low and work up” is never bad advice. Just don’t jump right to the max.

 

[rcorby2]

Long Cut, I also just picked up some VV N555 to study as an alternative to H4350 in 6.5 CM. I'm also using new Lapua SRP, CCI BR4, but with Berger 144gn LR Hybrids. When starting to explore a new powder, I like to play it safe. Per VV website, starting is 39.7gn and max is 43.2 gn. I like to start below the max about 2gn and work up in 0.5gn increments just to test the system for where I'll find pressure signs. Using this approach I loaded up 41.5gn - 43.5gn, one round every 0.5gn. I stopped at 43.5gn, not because it exceeds the max, but because it looked like I was about to be into compressed loads at 43.5. Note, my CBTO is 2.177", about 2.870 COAL. I had no pressure signs all the way up to 43.5gn, but am doing my load development in Winter temps (40 deg F). Anyway, you are loading well in safe zone per the VV site for your bullet. "Start low and work up" is very good advice. I'm running a velocity ladder later today, single round in 0.2gn increments from 41.2gn to 43.2gn.

 

[rcorby2]

@Long Cut

Here is how the ladder velocity test went...

VihtaVuori N555 Variable charge in 0.2GN increments
Lapua Virgin SRP Brass, no neck conditioning performed - just inspected and chamfered ID/OD
CCI BR4 Primer
Berger 144GN LR Hybrid Target, CBTO 2.177", Approximate COAL 2.870", jumping 0.070"
Max charge per VV website 43.2GN
Chronograph: Labradar
Temp: 43 deg F

Prior to firing these rounds I fired a three round group to ensure I was zeroed. This initial 3 round group w/41.6GN yielded Average MV of 2620, ES=5, STDEV=3.

41.2 2591 FPS
41.4 2604
41.6 2622
41.8 2633
42.0 2650
42.2 2654
42.4 2670
42.6 2687
42.8 2700
43.0 2710
43.2 2726 No pressure signs

Based on these results, I'll take a closer look at 42.1GN and perform a seating depth study with that charge.

 

[6-erlife]

@Long Cut

Here is how the ladder velocity test went...

VihtaVuori N555 Variable charge in 0.2GN increments
Lapua Virgin SRP Brass, no neck conditioning performed - just inspected and chamfered ID/OD
CCI BR4 Primer
Berger 144GN LR Hybrid Target, CBTO 2.177", Approximate COAL 2.870", jumping 0.070"
Max charge per VV website 43.2GN
Chronograph: Labradar
Temp: 43 deg F

Prior to firing these rounds I fired a three round group to ensure I was zeroed. This initial 3 round group w/41.6GN yielded Average MV of 2620, ES=5, STDEV=3.

41.2 2591 FPS
41.4 2604
41.6 2622
41.8 2633
42.0 2650
42.2 2654
42.4 2670
42.6 2687
42.8 2700
43.0 2710
43.2 2726 No pressure signs

Based on these results, I'll take a closer look at 42.1GN and perform a seating depth study with that charge.

View attachment 7482450

if you havent found pressure yet i would keep going up till u find pressure, i found that n555 seems closer to h4831sc

 

[kindabitey]

This may help:

Rifle reloading data | Handloading | Rifle calibers | Centerfire Rifle bullets | Reload your own ammo - Vihtavuori

Vihtavuori offers rifle reloading data for numerous calibers and bullets for match and hunting purposes. Never exceed maximum loads.

www.vihtavuori.com

 

[Long Cut]

@Long Cut

Here is how the ladder velocity test went...

VihtaVuori N555 Variable charge in 0.2GN increments
Lapua Virgin SRP Brass, no neck conditioning performed - just inspected and chamfered ID/OD
CCI BR4 Primer
Berger 144GN LR Hybrid Target, CBTO 2.177", Approximate COAL 2.870", jumping 0.070"
Max charge per VV website 43.2GN
Chronograph: Labradar
Temp: 43 deg F

Prior to firing these rounds I fired a three round group to ensure I was zeroed. This initial 3 round group w/41.6GN yielded Average MV of 2620, ES=5, STDEV=3.

41.2 2591 FPS
41.4 2604
41.6 2622
41.8 2633
42.0 2650
42.2 2654
42.4 2670
42.6 2687
42.8 2700
43.0 2710
43.2 2726 No pressure signs

Based on these results, I'll take a closer look at 42.1GN and perform a seating depth study with that charge.

View attachment 7482450

Awesome data, thank you so much!

Right now I have 22 rounds loaded up
10 rounds @ 40g COAL from 2.590” to 2.800”
3rds @ 41g 2.710” COAL
3rds @ 41.5 2.710”
3rds @ 42g 2.710
3rds @ 42.5g 2.710

I had some issues being a new reloader, achieving consistent COAL within my process, but my last 6 rounds all ended up being within .002” COAL. Last 3 rounds were actually the exact same COAL.

I’ll let you know how this works for my gun, although at this time I have no chronograph unfortunately.

Load setup-
Lapua SRP
CCI 400
Nosler BT 140g

 

[Zetlock]

@Long Cut

Here is how the ladder velocity test went...

VihtaVuori N555 Variable charge in 0.2GN increments
Lapua Virgin SRP Brass, no neck conditioning performed - just inspected and chamfered ID/OD
CCI BR4 Primer
Berger 144GN LR Hybrid Target, CBTO 2.177", Approximate COAL 2.870", jumping 0.070"
Max charge per VV website 43.2GN
Chronograph: Labradar
Temp: 43 deg F

Prior to firing these rounds I fired a three round group to ensure I was zeroed. This initial 3 round group w/41.6GN yielded Average MV of 2620, ES=5, STDEV=3.

41.2 2591 FPS
41.4 2604
41.6 2622
41.8 2633
42.0 2650
42.2 2654
42.4 2670
42.6 2687
42.8 2700
43.0 2710
43.2 2726 No pressure signs

Based on these results, I'll take a closer look at 42.1GN and perform a seating depth study with that charge.

View attachment 7482450

What was your barrel length for this test?