Vihtavuori N140 vs. N540, Relative merits?

[Krogen]

I've been happy with Varget in .223 Rem and 308 Win. But, being an inveterate fiddler I thought I'd explore Vihtavuori's powders. To date, I've only used N310 in .45 ACP bullseye loads. Of course, that's a different animal altogether. What's your experience with and advice for use of N140 or N540 in place of Varget?

 

[Laurie]

https://www.targetshooter.co.uk/?p=3856

One of a series of tests of alternatives to the now unavailable to us in the UK H4895 and VarGet. Note 30-inch barrel F rifle with very much longer freebore allowing ca. 0.7-1.0gn higher top charges with the 77gn SMK seated out for equivalent pressures to manufacturers' figures from SAAMI/CIP spec pressure barrels.

Both N140 and N540 acquitted themselves very well indeed against the same combination with VarGet. I remain very wary however of N540 as a probably high flame temperature propellant for not a huge MV increase before pressure signs appear. I know of too many 308 Win match quality F/TR barrels burned out at modest round counts in the past with heavy N540 loads.

Depending on your bullet weights, I'd strongly endorse N140 as a VarGet replacement in 223 and also in 308 with 155-175gn bullets; changing to N150 in 308 for 175-200gn match loads, although the 'quicker' grade is preferred by some with the Berger 185 Juggernaut and equivalents.

 

[Tangent]

https://www.targetshooter.co.uk/?p=3856

One of a series of tests of alternatives to the now unavailable to us in the UK H4895 and VarGet. Note 30-inch barrel F rifle with very much longer freebore allowing ca. 0.7-1.0gn higher top charges with the 77gn SMK seated out for equivalent pressures to manufacturers' figures from SAAMI/CIP spec pressure barrels.

Both N140 and N540 acquitted themselves very well indeed against the same combination with VarGet. I remain very wary however of N540 as a probably high flame temperature propellant for not a huge MV increase before pressure signs appear. I know of too many 308 Win match quality F/TR barrels burned out at modest round counts in the past with heavy N540 loads.

Depending on your bullet weights, I'd strongly endorse N140 as a VarGet replacement in 223 and also in 308 with 155-175gn bullets; changing to N150 in 308 for 175-200gn match loads, although the 'quicker' grade is preferred by some with the Berger 185 Juggernaut and equivalents.

Would you say the same about N550 hot? I have 1kg of it and was going to use it up on my .308 to try and get some more velocity out of it (20").

 

[Laurie]

Would you say the same about N550 hot? I have 1kg of it and was going to use it up on my .308 to try and get some more velocity out of it (20").

It depends on the load, pressures and rate of fire. Heavy N500 series charges / high pressures are hard on barrels with all of these grades, especially with heavy bullets, and you often notice barrel exteriors become warm or hot to the touch sooner than with the equivalent N100 grade. (I tried some N565 in my 6.5X55 F rifle with 142 SMKs recently, and was struck by how quickly the barrel heated up compared to my usual N165 load, a very cool burning low-energy propellant.) The one possible exception to this is N555 which has a modest nominal specific energy value.

As noted in the above Targetshooter piece, N550 gives very low pressures at normal MVs in some applications. In this event, I'd assume (no proof!) wear will be modest, possibly less than with an N100 grade running at higher pressures. I've certainly shot enough 550 in 308 over the years in modest pressure loads without problems. On the other hand, my F/TR 308 shooting friends tell me of some frightening barrel life figures running the much cooler burning N150 in super-heavy small primer brass loads with 185/200gn bullets. There are no free lunches - high pressures / MVs = more heat and wear whatever powder you use to achieve them.

You may also find N550 gives heavy muzzle blast from a 20-inch barrel. Year One of F/TR saw me shooting a 24-inch barrel factory rifle with 175gn SMKs and single-based powders at 1,000 yards and getting poor results in cool UK temperatures almost certainly from the bullet being well down transsonic zone speeds at the target, nudging subsonic in some conditions. A move to the 190gn SMK and a heavy charge of N550 did wonders for my scores and elevation consistencies, but the people shooting on either side of me complained about the muzzle blast and noise.

 

[Tangent]

It depends on the load, pressures and rate of fire. Heavy N500 series charges / high pressures are hard on barrels with all of these grades, especially with heavy bullets, and you often notice barrel exteriors become warm or hot to the touch sooner than with the equivalent N100 grade. (I tried some N565 in my 6.5X55 F rifle with 142 SMKs recently, and was struck by how quickly the barrel heated up compared to my usual N165 load, a very cool burning low-energy propellant.) The one possible exception to this is N555 which has a modest nominal specific energy value.

As noted in the above Targetshooter piece, N550 gives very low pressures at normal MVs in some applications. In this event, I'd assume (no proof!) wear will be modest, possibly less than with an N100 grade running at higher pressures. I've certainly shot enough 550 in 308 over the years in modest pressure loads without problems. On the other hand, my F/TR 308 shooting friends tell me of some frightening barrel life figures running the much cooler burning N150 in super-heavy small primer brass loads with 185/200gn bullets. There are no free lunches - high pressures / MVs = more heat and wear whatever powder you use to achieve them.

You may also find N550 gives heavy muzzle blast from a 20-inch barrel. Year One of F/TR saw me shooting a 24-inch barrel factory rifle with 175gn SMKs and single-based powders at 1,000 yards and getting poor results in cool UK temperatures almost certainly from the bullet being well down transsonic zone speeds at the target, nudging subsonic in some conditions. A move to the 190gn SMK and a heavy charge of N550 did wonders for my scores and elevation consistencies, but the people shooting on either side of me complained about the muzzle blast and noise.

Thanks Laurie. I've got either some 155gr Secnar-L or 178gr ELD-M to use up. I'm running suppressed so the blast may be mitigated somewhat.

 

[Lefty2506]

I started using N540 when I was shooting service rifle in the early 2000s. I was running 75gr Amax at the time, and N540 gave me 2950 out of my service rifle upper, and that REALLY helped at 600 yds when shooting at places like Camp Perry where the wind is always blowing. N140 also gave really good results, but the N540 was just faster and I wanted that because it ment shorter flight times at 600 yds.

The other cartridge that I was using VV powder for back then was a 7-08 which I was shooting from a 16" Encore pistol. I can't remember which of these 2 applications I started on first, but I know they were both at about the same time. I bought the Encore in '97, and the barrel must have been rougher than a corn cob. I could get good accuracy for about 10 rnds, and then I'd have to spend 20 min scrubbing it with copper remover and JB bore paste or the groups would go to crap. My goal was to have a 200 yd deer gun, but I was disappointed that I was only getting around 2300 fps with 140gr bullets. I don't remember what all powders I tried, but Varget was one of them. I finally tried molly coating my bullets and that helped a lot with the fowling issue I was having. I finally tried N140 on a whim and shot a 5 shot 1" group at 200 yds off the tailgate of my pickup truck using a rolled up flannel shirt as a rest because I really only wanted to know what the speed was (+2400 fps). That certainly caught my attention. I ended up trying N540 and N550 in it as well, and the N550 gave me the best speed while keeping my groups at around 1 moa. I think I was up closer to 2600 fps with N550 but my memory is pretty fuzzy back that far. From that point on, VV became my first choice for any new load that I was trying to work up. I'm currently using N530 for my 6.5G (also impressive with light weight .224 bullets), N133 for 53gr Vmax, N540 for heavy 223/5.56, N550 for the 7-08, and N340 for 45acp. I'll soon be moving to N340 for 9mm also (trying to burn up the last of a keg of AA#5 that I've had on the shelf since 1997).

 

[Tireguy]

I've been happy with Varget in .223 Rem and 308 Win. But, being an inveterate fiddler I thought I'd explore Vihtavuori's powders. To date, I've only used N310 in .45 ACP bullseye loads. Of course, that's a different animal altogether. What's your experience with and advice for use of N140 or N540 in place of Varget?

I have shot N540 since the late 90s. My experience with N540 is with the service rifle and AR match rifles.

To get the most out of this double based powder, I would recommend shooting molied bullets and i utilized a carrier weight. You will find in your load development that when you push the envelope, the groups just all of the sudden shrink to right on top of each other. From my experience, your load will end up somewhere north of 26.0 grains shooting 80 grainers. When that happens, you will be extremely happy with the group size and the speed your achieving. WITH all of that accuracy and speed your barrel life will be quite less and your brass is only good for about 2 to 3 firings....if your lucky.

There is some lot variance. I was launching Berger 80s over 3000fps out of a SR and getting 2 reloads out of the brass. Some lots came in slower and then some came back in over 3k fps. There were a few folks shooting 223 bolt guns and they could muster even higher speeds and great groups. If you're concerned about brass life, this is not the way to go.

I knew a few folks shooting N540 with naked bullets looking for that "next level" with N540 and the key was molied bullets. I honestly don't even know if moly is utilized that much any more....I can't remember the last time I saw molied bullets on the line.

Jon

 

[ronemus]

I shoot N-550 with 75 gr Hornady BTHP or A-max in a spacegun with 1:7 28" bull barrels (Krieger and Bartlein) and get good accuracy and velocity (typically 2930 fps), but accurate barrel life is ~3,500 rounds. I'll be switching to Reloder TS 15.5 when my N-550 runs out, and I hope for better barrel life. Brass life is very good - I'm at 12 reloads with LC and 9 with Winchester, and still counting.

 

[kyotekiller25]

I shoot 24.7gr of N540 with 75g ELDMs from a 28" 223 bolt gun out to 1K and it gives me 2975fps and 3/4 MOA 10 shot groups at 100 yards. I can easily run it up to 3050fps at 25.3gr, but it's towards the upper limit for the rifle/combo and brass life would be sacrificed significantly. Not worth the extra 75fps.

 

[Krogen]

This is great information! Thanks for all the comments.

Laurie, your article on Targetshooter is excellent. I read through it several times, each time picking up more to chew on. Have I decided on trying N140 or N540? Not yet. I think I'll have to buy some of each.

 

[barefooter56]

It depends on the load, pressures and rate of fire. Heavy N500 series charges / high pressures are hard on barrels with all of these grades, especially with heavy bullets, and you often notice barrel exteriors become warm or hot to the touch sooner than with the equivalent N100 grade. (I tried some N565 in my 6.5X55 F rifle with 142 SMKs recently, and was struck by how quickly the barrel heated up compared to my usual N165 load, a very cool burning low-energy propellant.) The one possible exception to this is N555 which has a modest nominal specific energy value.

As noted in the above Targetshooter piece, N550 gives very low pressures at normal MVs in some applications. In this event, I'd assume (no proof!) wear will be modest, possibly less than with an N100 grade running at higher pressures. I've certainly shot enough 550 in 308 over the years in modest pressure loads without problems. On the other hand, my F/TR 308 shooting friends tell me of some frightening barrel life figures running the much cooler burning N150 in super-heavy small primer brass loads with 185/200gn bullets. There are no free lunches - high pressures / MVs = more heat and wear whatever powder you use to achieve them.

You may also find N550 gives heavy muzzle blast from a 20-inch barrel. Year One of F/TR saw me shooting a 24-inch barrel factory rifle with 175gn SMKs and single-based powders at 1,000 yards and getting poor results in cool UK temperatures almost certainly from the bullet being well down transsonic zone speeds at the target, nudging subsonic in some conditions. A move to the 190gn SMK and a heavy charge of N550 did wonders for my scores and elevation consistencies, but the people shooting on either side of me complained about the muzzle blast and noise.

Laurie,
I was told the same thing about N-550 at CAMP PERRY when I shot PALMA. I had no issues with barrel life with that powder. 155 SMK 3030 FPS 30 INCH BARREL.

 

[Laurie]

Laurie,
I was told the same thing about N-550 at CAMP PERRY when I shot PALMA. I had no issues with barrel life with that powder. 155 SMK 3030 FPS 30 INCH BARREL.

Phil, I'm not too surprised as that load will give quite moderate pressures. As I said in my post , I have years of experience shooting the 308 with N550 and been very happy with the outcomes. (I've just loaded up a range of charges in the powder under the old 175 SMK to test against the new Winchester StaBALL 'Match' so-called wonder-powder and hope to test both tomorrow.)

I have a former F/TR shooting friend who ran nothing but the old 210 Berger BTs and N550 over many years until he retired from the discipline and it worked very well for him providing a good trade-off between performance and barrel life. The 'problem' with N550 is that very high MVs are available in 308, which is a great thing as long as people understand there will almost certainly be a cost to them once they pass a certain performance point. There are those who know exactly what they're doing in such loads and take every last available fps knowing that barrel life will be modest, even poor, and accept that, but there are others who don't appreciate this - they love the performance, boast about their MVs, then switch mode to moaning loudly to anyone who'll listen when the barrel is suddenly shot out! But as I also said in the post, I also know of people today obtaining the last potentially available bit of MV from heavy bullets and lower energy single-based powders in Lapua 'Palma' small-primer brass in 308 F/TR, and finding that last 50 or 100 fps is very expensive in barrel life simply because of the pressures they're running at allied to the bullet weights. So, I don't say to people they shouldn't use N550, but warn them to keep pressures sensible. We really have little excuse these days with very accurate, reliable chronographs.

N540 might have been a different matter for you though especially with a bit higher MV. In the early days of F/TR many of us in the UK worked up 155gn Scenar loads with this powder. I was running them at 3,075 fps (30-inch barrel) and the barrel was 'gone' in under 1,500 rounds. (To be fair, nobody knew about MVs and pressures rising after a couple of hundred rounds down the barrel in those days, so the final MV may have been higher.) Two friends with identical Bartleins to mine (we bought them as a single transaction) ran 'hotter' and got 1,000-1,100 rounds. Remember we pairs-shoot in the UK so no red hot barrels from fast 'string shooting' either, and some matches we shot were in damn cold conditions too. Although Viht gives N540 the same nominal specific energy rating as most other N500s, I still have a prejudice that it is a very hot propellant based on those early F/TR days, which may well be unfair to it.

 

[barefooter56]

Phil, I'm not too surprised as that load will give quite moderate pressures. As I said in my post , I have years of experience shooting the 308 with N550 and been very happy with the outcomes. (I've just loaded up a range of charges in the powder under the old 175 SMK to test against the new Winchester StaBALL 'Match' so-called wonder-powder and hope to test both tomorrow.)

I have a former F/TR shooting friend who ran nothing but the old 210 Berger BTs and N550 over many years until he retired from the discipline and it worked very well for him providing a good trade-off between performance and barrel life. The 'problem' with N550 is that very high MVs are available in 308, which is a great thing as long as people understand there will almost certainly be a cost to them once they pass a certain performance point. There are those who know exactly what they're doing in such loads and take every last available fps knowing that barrel life will be modest, even poor, and accept that, but there are others who don't appreciate this - they love the performance, boast about their MVs, then switch mode to moaning loudly to anyone who'll listen when the barrel is suddenly shot out! But as I also said in the post, I also know of people today obtaining the last potentially available bit of MV from heavy bullets and lower energy single-based powders in Lapua 'Palma' small-primer brass in 308 F/TR, and finding that last 50 or 100 fps is very expensive in barrel life simply because of the pressures they're running at allied to the bullet weights. So, I don't say to people they shouldn't use N550, but warn them to keep pressures sensible. We really have little excuse these days with very accurate, reliable chronographs.

N540 might have been a different matter for you though especially with a bit higher MV. In the early days of F/TR many of us in the UK worked up 155gn Scenar loads with this powder. I was running them at 3,075 fps (30-inch barrel) and the barrel was 'gone' in under 1,500 rounds. (To be fair, nobody knew about MVs and pressures rising after a couple of hundred rounds down the barrel in those days, so the final MV may have been higher.) Two friends with identical Bartleins to mine (we bought them as a single transaction) ran 'hotter' and got 1,000-1,100 rounds. Remember we pairs-shoot in the UK so no red hot barrels from fast 'string shooting' either, and some matches we shot were in damn cold conditions too. Although Viht gives N540 the same nominal specific energy rating as most other N500s, I still have a prejudice that it is a very hot propellant based on those early F/TR days, which may well be unfair to it.

I understand Laurie. The only issue I had with the N-550 was that it got hotter as it aged and I wasnt smart enough back then to notice it a I would now and test it each year. Accuracy wasn't affected also due to the TANGENT OGIVE bullet jump tolerance. Camp Perry was hard on people and equipment at times due to the heat and humidity combined with string shooting. Those were the days! I am working on a mid-range 223 REM F-TR rifle and will start with the N-540 with the 70 VLD or 73 BT TARGET BULLET. Just to see if I can still do it before I step up to a barrel with a twist rate for our 85.5 LRHT bullet.