Node issues

[NickolasG]

Hi AS

Im really stuck, and could use a tip or two.

So, normally I shoot:
167gr Scenar
Norma brass
N540 43.8 gr
CCI BR-2
2454 average-fps

In a Sig716 patrol (AR-10) with group size around 0.6 MOA

In Europe we have supply issues, getting forexample CCI BR-2 etc.
I was lucky to find Fed210M, and Lapua .308 brass - but! now my load needs to be rebuilded.

I’ve made several latters with N540 and N150.
N540 is for sure not a match with fed210M in this setup, with bad ES/SD and group size.
Group sizes varied from 1.1” - 1.6” MOA
I’ve also had really! Sooty brass, this was not the case with N150.

The best result was seen with ONLY:
Scenar 167gr
N150 44.9gr (0.1gr above Max load)
Fed 210M
Lapua brass
2539 average fps

Did a 0.9” MOA group
With ES/SD = 7.7 fps / 2.6 fps

Im still not happy with this.
Do any of you guys have any good advices?
- I only have access to vihtavouri powders, if suggesting other components.


… Greetings from Denmark

 

[Deleted member fkimble@charter.net]

N540 is too slow for a 167/168 weight bullet. It might work with a 190, probably ok wit a 200/+. The sooty brass tells me the load is not developing enough pressure to seal the chamber. Give 140 a try. It is approx same rate as 4895 which is an ideal 308 powder.

Frank

 

[SeabeeKen]

I would try some N-140 or N-135. Sounds as though you may be getting poor ignition on the double base N-540. It could also be as Frank said, a bit too slow. N-540 is normally a hot burning powder also. N-150 would be too slow in my opinion. Hope this helps

 

[Doghed]

I agree with the above.
I recently began building a similar load for a 308 bolt gun.
I haven't done load development yet, but I was getting one inch 15 shot groups while fire forming using N140 in Lapua Palma brass under the 169 SMK and the 168 A-MAX (CCI 450).
I don't have chrono data yet, but POI was the same as my 175 SMK load using Varget and 210M's in 5x fired Nosler LRP brass going 2575 fps.
I'm very happy with that starting point.

 

[Allen Corneau]

Since it hasn't been mentioned yet... played with various seating depths yet?

 

[Bc'z]

N540 is too slow for a 167/168 weight bullet. It might work with a 190, probably ok wit a 200/+. The sooty brass tells me the load is not developing enough pressure to seal the chamber. Give 140 a try. It is approx same rate as 4895 which is an ideal 308 powder.

Frank

What about adjusting neck tension?
1 or 2 thousands more may overcome the start preasure.

 

[bozo699]

Hi AS

Im really stuck, and could use a tip or two.

So, normally I shoot:
167gr Scenar
Norma brass
N540 43.8 gr
CCI BR-2
2454 average-fps

In a Sig716 patrol (AR-10) with group size around 0.6 MOA

In Europe we have supply issues, getting forexample CCI BR-2 etc.
I was lucky to find Fed210M, and Lapua .308 brass - but! now my load needs to be rebuilded.

I’ve made several latters with N540 and N150.
N540 is for sure not a match with fed210M in this setup, with bad ES/SD and group size.
Group sizes varied from 1.1” - 1.6” MOA
I’ve also had really! Sooty brass, this was not the case with N150.

The best result was seen with ONLY:
Scenar 167gr
N150 44.9gr (0.1gr above Max load)
Fed 210M
Lapua brass
2539 average fps

Did a 0.9” MOA group
With ES/SD = 7.7 fps / 2.6 fps

Im still not happy with this.
Do any of you guys have any good advices?
- I only have access to vihtavouri powders, if suggesting other components.


… Greetings from Denmark

NickolasG,
Welcome to the forum. Sounds like you have been given some good advice, I don’t have anything to add but I can tell you something about CCI primers. There is absolutely no difference between BR2’s and 200’s the only difference is when testing them lots that are more consistent get put in a br cup .
Best of luck to ya.
Wayne

 

[jeniusit]

Ciao AS

Sono davvero bloccato e mi servirebbero un consiglio o due.

Quindi, normalmente scatto:
167gr Scenario
Norma ottone
N540 43,8 gr
CCI BR-2
2454 fps medi

In una pattuglia Sig716 (AR-10) con una dimensione del gruppo di circa 0,6 MOA

In Europa abbiamo problemi di approvvigionamento, ad esempio per quanto riguarda CCI BR-2 ecc.
Sono stato fortunato a trovare Fed210M e bossoli Lapua .308, ma ora la mia carica deve essere ricostruita.

Ne ho realizzati diversi con N540 e N150.
In questa configurazione, N540 non è sicuramente all'altezza di fed210M, con ES/SD e dimensioni del gruppo scadenti.
Le dimensioni del gruppo variavano da 1,1" a 1,6" MOA
Ho avuto anche davvero! Ottone fuligginoso, questo non era il caso con N150.

Il miglior risultato è stato riscontrato SOLO con:
Scenario 167gr
N150 44,9gr (0,1gr oltre il carico massimo)
Federale 210 milioni
Ottone Lapua
2539 fps medi

Ha fatto un gruppo da 0,9" MOA
Con ES/SD = 7,7 fps / 2,6 fps

Non ne sono ancora soddisfatto.
Qualcuno di voi ha qualche buon consiglio?
- Se vuoi suggerire altri componenti, ho accesso solo alle polveri di vihtavouri.


… Saluti dalla Danimarca

N150 43,30 gr BR4

 

[Doom]

Since you are shooting a semi-auto gas gun with a short barrel you will probably be better served with N135 or N140 and the 167 Scenar. I would also recommend you try more neck tension.

 

[NickolasG]

Hi Everyone

Thank you for the warm welcome!
I've definitely learned a lot here, and I really appreciate it.

I understand that the general consensus is that N540/150 is too slow for my setup, and that I should try N140 or N135 instead—given my bullet weight and the fact that I’m using a short-barreled gas gun.

I've experimented with crimp and seating depth, but neither made a significant difference. I'm surprised by how much of an impact switching primers can have on ignition, but I suppose this is a great lesson in how various parameters interact.

I've now prepared a new ladder test with N140 and will be heading to the range next weekend. I’ll share the results here for those who might be interested.

 

[Jon Turner]

Since it hasn't been mentioned yet... played with various seating depths yet?

Beat me to it.