Help with 308 win

[moe africa]

Good Day
I've recently moved from 6.5 Creedmoor to 308 Win
The rifle is for PRS tactical class
The first loads I tried ranged from 43gr to 45gr of VV N150 with 175gr Nosler custom competitions
It's produced good velocity spreads (SDs of between 3 and 6)
Yet only 45gr produced a sub .5moa group
Once that was retested it produced a .85" group with 45gr and SD of 5.7 with an Average velocity of 2730 for 15 shots (24" bbl)
I then tested VV N540 which had extremely small velocity spreads ( SD under 3 for 3 different charges)
The groups were much smaller
The best groups and velocity spread was at an approximate pressure of 55k psi
Barrel life is a major concern down here and I would like to maximize it as much as I can
Anyone with experience regarding
1. N150 not working well ?
2. N540 in a 308 ?
Should I potentially try varget

 

[RegionRat]

Varget is a single base powder and always worth a try where appropriate.

All other things being equal, the single base powders will be less temperature sensitive and potentially give a longer barrel life. That said, your shooting tempo is the bigger variable in barrel life, so I would still go with whatever makes the rig happy and not base it on extrapolated guesses on barrel life.

 

[Alaska Bush Man]

Varget or ADI 2208
165/168 at 46.0
180 at 44.0
150/155 @ 47.5

WW Brass and CCI BR2 primers

 

[Nvcnvc]

If Varget doesn’t work with 175s, try N140 instead of N150. N150 would probably do better with 185s and 200 gn bullets.

 

[coldboreshot]

Agree. Move to N140 and test. I run this in my 175SMK load and it performs very well, even at 1000yds. Many years ago, I discovered that N140 and Varget ran grain-for-grain in my loads, back during the Obama years when you stood a better chance of finding a unicorn next to a pot of gold at the end of a rainbow, than locating Varget.

 

[10XSHOOTER]

IMR-4064 42.0-43.0 with a 175
Try a different bullet instead of the Nosler. 175 Sierra

 

[LVLAaron]

N150 is probably the best 308 powder for heavy bullets. For a 175 AR-Comp is my go to. Have you adjusted seating depth or are you just changing loads?

 

[Nvcnvc]

I heard about AR comp and got a lb to try. Is it better suited for heavies or light bullets? Thanks

 

[kevinbritvec]

You aren't happy with .5 to .85" groups and single digit SD's?

N150 is a single base powder, N540 is not. IMO, you are 100+ fps faster than you need to be. A lower accuracy node may shoot tighter for you.

Powders containing nitroglycerine spike pressures in high temperatures. Laurie Holland is a big proponent of N150 in .308. I think he knows a thing or two regarding loads in this cartridge.

 

[alphapygmy]

Try a different bullet instead of the Nosler. 175 Sierra

+1. Try 175 SMK or 175 Berger OTM. AR-Comp is awesome but probably hard to get some.
I've also had pretty good results with 168 ELDM and N150 running a lower node. It's been very easy on brass and barrel so far. Lapua SRP and 450's with 42.5 N150.
22" barrel runs low 2600's with very low SD and averages .6ish for 5 at 100.

 

[DanSavage]

Varget or ADI 2208
165/168 at 46.0
180 at 44.0
150/155 @ 47.5

WW Brass and CCI BR2 primers

Those are some pretty stout loads Bush Man! That would be over pressure in all 3 of my .308 barrels, a factory Savage, a Shilen s match, and a Shaw. They all have rather short throats though, I won’t even touch those barrels again unless throats are lengthened so I can better shoot the heavies. My barrels are all 10 twist too,,, you’d think they would throat out the chambers on the faster twist barrels with more cartridges than just .308
I have a 7 twist .223 that came with short throat too! lol

 

[padom]

IMR4064 is my go to 308win powder and has been for a very long time. Stupid accuracy..

Here some testing with a new jug of 4064 out if my 24" Krieger with the 308win Bisley chamber...

175smk OCW

https://imgur.com/61OIpCB

175 SMK final load 5x5 @ 100yd

https://imgur.com/PGBHsA0

177smk

https://imgur.com/zlO7oyO

 

[D-4297]

As others have mentioned ; You may have better luck with the 185 Berger Target and
N150 . My TR load for 600 yards was 43.2gr , using Lapua SRP Brass and Rem 7 1/2 primers , and gave me a velocity of 2655 -2665 , and the SD ran a very consistent 4.2 - 5.3 !

 

[smithmtva]

IMR 4064 or Varget seem to always work well.