Vihtavuori N-570 for 338 Lapua

CCooper

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I just got 2 lbs of N-570 from Powder Valley and all I can say is this is the worst handling powder I've ever dealt with. The kernels are too LARGE. I'm a big Vihtavuori fan (it's always been the most consistent from day to day for me), but I'm a little disappointed in the size of the kernels. Is there a reason for the extremely large kernels. I've been shooting Retumbo with good results, but the day to day #'s are the reason I tried N-570. One day with Retumbo, I'll get around 2875 fps for an average and the next (similar temps.), I'll get around 2825 or less. Retumbo, so far seems to give about 50-75 fps better speed with similar pressures.
 

C.K

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Re: Vihtavuori N-570 for 338 Lapua

and you'll gain another 50 with n570 over retumbo. you'll use up the same or less of the case cap with n570.
 

CCooper

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Re: Vihtavuori N-570 for 338 Lapua

From what little testing I've done so far, I don't believe N-570 will give the same speeds as Retumbo and it seems to fill the case more. 93grs N-570 seems about the same as 95 grs Retumbo pressure wise and also seems to fill the case a little more. I'm not after speed as much as consistency, though.
 

codyc

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Re: Vihtavuori N-570 for 338 Lapua

Agree with you they are Big kernels. Need to be about half size. Little bit of a hassle getting my powder measure perfect but once I do it shoots very consistent out of my TRG.

Interested in your findings in terms of consistency.

C
 

hexades1

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Re: Vihtavuori N-570 for 338 Lapua

I do not have any experience with Retumbo but a lot of my friends use N570 with 250 Scenars here in Finland.

The bottom line is that it is actually pretty hard to load too much N570 powder with 250 Scenars -> Safe powder. People here have been getting close to 950 m/s (3166 fps) with max loads of N570 out of the factory TRG-42s. These are of course over the Vihtavuori manual maximums but if you keep an eye on pressure signs this is still within reasonable pressures. Sierra 250 Match King is a different bullet and this might not be true for it.

Typically people end up tailoring loads to apprx 900-905 m/s i.e. 3000-3016 fps. This is similar to factory Lapua loads, shoots well and recoil is kept on tolerable levels with muzzle brakes or suppressors.

I load 88,0 greins N560 as it is less dirty (less graphite coating) and I get 907 m/s without any pressure problems whatsoever. My rifle has minimum spec cahmber and 720mm i.e. 28.3" barrel so is is longer than TRG-42 tube. I get 920-925 m/s with Lapua factory ammo but TRG-42 with factoory chambers and barrels get usually 880-890 m/s with it when new.

Of VV powders N560, N570 and N170 need to be weighted. With RCBS electronic combo or with a basic electronic scale and trickler. No way around weighting. N550 can be metered with a RCBS Uniflow or Harrel but that powder is too fast for 338LM. For 308 Win laods with heavy bullets a very good powder.

Some bench rest oriented people like to use N-165 but it does not give maximum speeds.

Use what works for you. Here in Finland N560, N570 and N170 rule when loading 338LM but that is BECAUSE we do not have anything else available.

We will get soon Norma powders again after a 20 year break. Norma MRP-2 is closest canister powder to what Lapua uses to load their mil-spec ammo. Very temperature tolerant and accurate. If you can get Norma MRP-2 you might want to try it.
 

Fredo

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Re: Vihtavuori N-570 for 338 Lapua

These were my loads. Kroil and nylon brush owns the powder fouling.

VVN570, 300gr Scenar's.

3.735 OAL, Fed 215M primers in once fired Lapua neck sized.
DTA/SRS .338LM 26"

90 grains = 2,786 Avg.
92 grains = 2,851 Avg. this was .5 MOA
93 grains = 2,875 Avg.
94 grains = 2,913 Avg. crushing powder stack seating.
 
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C.K

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Re: Vihtavuori N-570 for 338 Lapua

Load data for my 338Norma Mag shooting 300gn scenar's

91.5 ramshot mag=2763 avg.

92 Retumbo=2853 avg

93.5 Vit n570=2917 avg
 

LANCER

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How are people not getting pressure signs with over 90 gr of N-570 and 300 scenars? I started my latest satterlee test at 90.2 and my first low load I had to pound the bolt open with a deadblow hammer for extraction. Flat primers, hint of ejector shadow on the brass. My previous load was 88.3 grains, 300gr Scenar, around 2700 fps velocity and almost 2800 (too hot) in 102 degree weather. (Lapua brass) I changed brass to Prime 1x fired (norma) that has 3grains additional H2O capacity than the Lapua and I was hitting pressure 3 grains below max. Crunchy seating for OAL of about 3.655 which is 20-25 thou off the lands. Brass is all shoulder bumped (FL) .002 exactly. This is out of a Barrett MRAD. I have to restart my Satterlee development on this brass and had to pull all my rounds from the first attempt. I'm also shooting in very hot weather almost always above 100 degrees and found N570 to be very temp sensitive. Has anyone tried N565 with 300's? It says that powder is formulated for 250's, and not sure if I should switch away from N570. Smaller kernels would be nice. This shit is cordwood and completely locks up my Autotrickler V3. Even just the trickler locks up occasionally with this powder when I use a RCBS thrower for the initial throw. My chamber is clean (borescoped it), I'm not jamming the lands, and barrel recently came back from Barrett for a headspace adjustment. (I unscrewed the extension and couldn't tighten it properly to correct headspace)
Any thoughts?
 

babyguppy

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Did you give up on the N570 and go back to Retumbo, H1000 or N560? Curious since you mentioned the 100 degree weather while shooting.
Is a 1 year old thread a zombie thread? ;)
 

Graye2

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I haven’t tested the 300gr scenars but have tested 300gr SMK’s. I had better consistency at higher MV with N570 than Retumbo. I had good consistency at 2620 ft/s in both powders but also had great results at 2670 ft/s with 90.4gr N570. My testing was done on a 26” Desert Tech. I didn’t come any where near the velocities mentioned in the original threads but I was also at 55F and not 100F. All tests were in Lapua brass.

I agree on the kernel size but after seeing the Beta V4 that should solve most if not all powder challenges.
 

LANCER

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Did you give up on the N570 and go back to Retumbo, H1000 or N560? Curious since you mentioned the 100 degree weather while shooting.
Is a 1 year old thread a zombie thread? ;)
I haven't used N-570 since last year, because I've been trying to use up my old stash of IMR 7828 SSC. That powder is a bit fast, so have to be careful, and I stopped at 80 grains under a 300 scenar. (not the ideal combo) It yields 3/8 inch groups at 100 and it hammers at 1000 yards which is the max I shoot at. Muzzle velocity is right around 2625 fps (slow but sufficient for range) No pressure signs but I think it has the potential to spike in hot weather so I keep it slow and safe.
Just got a batch of 285 ELD-M's which will be my next workup and I'll be breaking out new brass for the load. I'll be using N-570 for this as I just got another 10 pounds of it on trade. If it doesn't shoot or shows pressure way before book max, I'll then try US-869 which I've shot before and meters like water. Maybe it will like the lighter ELD-M's. Did not group very well with 300 Scenars.
 

stefan73

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    I have been trying RL-33 and Hornady 285's. Seems to work pretty well but I haven't been able to stretch its legs out.

    I am still running N570 and seeing around 2800fps pushing 300 grn Scenars and SMK's.
     
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    babyguppy

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    slightly off topic but close on the burn chart. I picked up some N560; since I read that N570 kernals (granulars?) were a bit long. I'll know more in about 2 weeks when I can run some groups. I'll be trying them out with 300 grain Berger hybrid OTMs
     

    Steel head

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    slightly off topic but close on the burn chart. I picked up some N560; since I read that N570 kernals (granulars?) were a bit long. I'll know more in about 2 weeks when I can run some groups. I'll be trying them out with 300 grain Berger hybrid OTMs
    N570 is like Lincoln logs but it’s an awesome powder.
    I use it in 338 edge
     

    JJMoody

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    Thanks. Trying to compile a bit more data on 570 with the +p chamber. Scored an 8 recently. Was looking at data for H1000 and retumbo til I picked up this jug.
     

    Steel head

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    Thanks. Trying to compile a bit more data on 570 with the +p chamber. Scored an 8 recently. Was looking at data for H1000 and retumbo til I picked up this jug.
    I kinda used midpoint retumbo data as a start point for my edge.
    I’m just shooting 265 and 285 solids but 95 grains is a decent place to start without being too low in a regular edge in my barrel.
     
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    LANCER

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    It'll work great for either one. I think they should rename N570 to Big Stupid Magnum Powder, it's the best performing option in all of my big stupid magnums.
    I'm laughing at the "big stupid magnums" remark. That's funny and I'm stealing it.
     

    babyguppy

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    ok, slightly off topic, but I wanted to follow up with my results on N560. I tested the N560 out on 250 gr Berger Elite Hunters. I didn't test on the 300 grain Berger OTMs; since I found 'my' 300 grain load with 92 grains of H1000 (.173" or .165 MOA at 100 yards using Ballistic X @ 2868 fps).
    The 250 grain Elites with N560 produced the following: (I did NOT run a 5 shot std dev or ex spread) this is a 1 shot FPS.
    FYI - TRG 42, 1X10 twist 27" barrel.
    COAL - 3.73 (Max Magazine length)
    88.5 grains - 2904
    89 grains - 2932
    90 grains - 2964 (book maximum load @ 3.68 COAL Sierra 5th edition)
    91 grains - 3005
    The N560 88.5 grains produced the best group @ .372" (.355 MOA at 100 yards using Ballistic X) 99 degrees F @ 1398 elevation.
     
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    Dogtown

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    N560 is excellent for .338LM with 250s. I get a bit more velocity than with RL25.