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Any long time Vihtavuori users?

mtmuley

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I've read some concerns that Vihtavuori powders can contribute to premature throat erosion. Anyone here used it for an extended period and have any thoughts? mtmuley
 
I've used 2# of N570 (about 160 rounds), and 60 rounds of rl22 to form some brass in this 7STW during the process, and the throat has moved over 50 thou. Went from roughly 1/2 moa at 600 to just a twitch over 1moa. I did shoot those 60 rounds of rl22 over two days which wasn't very bright.

after some load dev at 100 yards; one sighter, then 3 at 600
1.jpg

made a stock adj then went back a week later. Two sighters then 5 at 600

2.jpg

The shit's magic with 195's but it's a flame thrower.
 
N570 is pretty good stuff, havent seen any extra errosion (sure there is standard creep) in my Norma but dont borescope either. I run mine about 80 feet slower than pressure signs start showing in 2nd fastest node i liked, so not a max load. Do see some soot or carbon residue but cleans easy and accuracy is better than i can shot with ES is low single fps for me. Use it in longer range rifles its worth the premium for the added consistency.
 
I load .300 PRC with N568 under 220 ELDX for my hunting partner. Shoots great but a little slower, but read lots that it doesn’t have near as much nitro in it as N570. I’ve read the same barrel burning/throat erosion issues, but it’s still the best load I’m finding for my PRC and 199 HH. So the decision is keep the load and sacrifice ~200 rds of barrel life or walk away? I think I’m going to try and walk the line - keep the load, shoot it enough to have good dope, but also keep a H1000/Berger load in my back pocket for bulk shooting.
 
I have four powders suitable to use. Velocity is gonna win. I guess in the grand scheme barrel life is secondary anyway. mtmuley
 
Is there a sufficient volume difference such that the more you burn the more erosion that you should get?
 
I've read some concerns that Vihtavuori powders can contribute to premature throat erosion. Anyone here used it for an extended period and have any thoughts? mtmuley
I've used Vihtavuori in 2 rifles I found a couple pounds cheap at the start of 2020, I wasn't getting the velocities I wanted in the .308 but in the 6.5 I got good results. I've loaded a couple hundred rounds with the N550 haven't noticed any erosion problems
 
The heat of explosion that I think folks are discussing here isnt a viht thing it’s individual powder specific. For example, N165 is a very cool burning powder but n570 is on the hot end of the spectrum.

RL33 is pretty close to n570 on the spectrum.

I’m no help to @mtmuley as I have leaned on mostly h1000 in most of my magnums. Retumbo is cooler burning too.
 
I have used it for the last couple rifles I have had. N565 in 6.5PRC and N570 in 28 nosler. In low volume hunting rifles I haven't noticed any problem with erosion, maybe in high volume prc rifles it would be more noticeable. Even if it burned out barrels quicker I would still use it, new barrels are not too big of a deal.
 
The heat of explosion that I think folks are discussing here isnt a viht thing it’s individual powder specific. For example, N165 is a very cool burning powder but n570 is on the hot end of the spectrum.

RL33 is pretty close to n570 on the spectrum.

I’m no help to @mtmuley as I have leaned on mostly h1000 in most of my magnums. Retumbo is cooler burning too.
I'm no help for mtmuley either, but I'm curious if you've used N165? I also have read it's a very cool burning powder. It seems to be pretty popular in the 6mm AI crowd so I've considered trying it in mine. I've heard it can be temp sensitive, at least moreso than the typical IMR powders and especially the hodgdon extreme powders.
 
I'm no help for mtmuley either, but I'm curious if you've used N165? I also have read it's a very cool burning powder. It seems to be pretty popular in the 6mm AI crowd so I've considered trying it in mine. I've heard it can be temp sensitive, at least moreso than the typical IMR powders and especially the hodgdon extreme powders.

I never have just because of the temp sensitivity claims.
 
The heat of explosion that I think folks are discussing here isnt a viht thing it’s individual powder specific. For example, N165 is a very cool burning powder but n570 is on the hot end of the spectrum.

RL33 is pretty close to n570 on the spectrum.

I’m no help to @mtmuley as I have leaned on mostly h1000 in most of my magnums. Retumbo is cooler burning too.
So burn rate must have nothing to do with the temp a powder burns then? I can guess the rounds through my RUM barrel. Be interesting to see what it looks like when the Smith pulls it off after a steady diet of RL-25. mtmuley
 
So burn rate must have nothing to do with the temp a powder burns then? I can guess the rounds through my RUM barrel. Be interesting to see what it looks like when the Smith pulls it off after a steady diet of RL-25. mtmuley

They are independent of each other at least how they are rated. RL25 is middle of the road. Hodgdon varget and H4895 are hotter than most everything and they are pretty fast burning and still two of the most popular powders in high volume competition rifles albeit in smaller cartridges.

H50bmg is particularly mean to barrels in theory because it’s hot and takes a lot of powder to get pressure!

What I could find online for an older list of various powder ratings, N570 is 3950 I believe, RL33 is 3900:

1.) Vihtavuori N530 4100 kJ/kg
2.) Vihtavuori N540 4100 kJ/kg
3.) IMR 4895 4080 kJ/kg
4.) Hodgdon H4895 4060 kJ/kg
5.) Hodgdon VARGET 4050 kJ/kg
7.) Vihtavuori N550 4050 kJ/kg
10.) IMR 4227 4040 kJ/kg
11.) Vihtavuori N560 4020 kJ/kg
12.) Accurate Accurate 1680 4018 kJ/kg
13.) Norma URP 4017 kJ/kg
14.) Hodgdon 50BMG 4010 kJ/kg
15.) Ramshot Enforcer 4005 kJ/kg
16.) Alliant Reloder-10x 4000 kJ/kg
17.) Hodgdon H322 4000 kJ/kg
18.) Vihtavuori N110 4000 kJ/kg
19.) Alliant Reloder-15 3990 kJ/kg
20.) Alliant Reloder-17 3990 kJ/kg
21.) Alliant Reloder-22 3990 kJ/kg
22.) Hodgdon BL-C2 3990 kJ/kg
23.) Alliant Reloder-19 3980 kJ/kg
24.) Hodgdon H335 3980 kJ/kg
25.) Winchester WXR 3980 kJ/kg
26.) Hodgdon H380 3970 kJ/kg
27.) Norma 203B 3957 kJ/kg
28.) Ramshot X-Terminator 3950 kJ/kg
29.) Ramshot TAC 3950 kJ/kg
30.) Norma 200 3940 kJ/kg
31.) IMR 4007 SSC 3935 kJ/kg
32.) IMR 8208 XBR 3920 kJ/kg
33.) Ramshot BigGame 3920 kJ/kg
34.) Alliant Reloder-7 3910 kJ/kg
35.) IMR 4198 3910 kJ/kg
36.) Ramshot Hunter 3910 kJ/kg
37.) Hodgdon Benchmark 3900 kJ/kg
38.) Norma 203 (old) 3900 kJ/kg
39.) Norma 201 3894 kJ/kg
40.) IMR 4320 3890 kJ/kg
41.) Accurate Magpro 3880 kJ/kg
42.) Hodgdon H414 3880 kJ/kg
43.) IMR 3031 3880 kJ/kg
44.) IMR 4064 3880 kJ/kg
45.) Winchester 760 3880 kJ/kg
46.) Norma MRP 3873 kJ/kg
47.) Hodgdon H4831SC 3870 kJ/kg
48.) Hodgdon H4831 3870 kJ/kg
49.) Hodgdon H4198 3860 kJ/kg
50.) Norma 202 3852 kJ/kg
51.) Norma 204 3852 kJ/kg
52.) IMR 7828 3850 kJ/kg
53.) IMR 7828 SSC 3850 kJ/kg
54.) Vihtavuori N130 3850 kJ/kg
55.) Winchester 748 3840 kJ/kg
56.) Alliant Reloder-12 3830 kJ/kg
57.) Alliant Reloader-50 3820 kJ/kg
58.) Accurate Accurate 2495 3810 kJ/kg
59.) Accurate XMR 3810 kJ/kg
60.) Alliant Reloder-25 3810 kJ/kg
61.) Hodgdon H870 3810 kJ/kg
62.) Accurate Accurate 4350 3790 kJ/kg
63.) Vihtavuori 24N41 3785 kJ/kg
64.) Ramshot Magnum 3775 kJ/kg
65.) Norma 217 3766 kJ/kg
66.) Hodgdon H4350 3760 kJ/kg
67.) IMR 4350 3760 kJ/kg
68.) Accurate Accurate 2015 3754 kJ/kg
69.) Vihtavuori N140 3750 kJ/kg
70.) Vihtavuori N150 3750 kJ/kg
71.) Winchester Supreme 780 3750 kJ/kg
72.) IMR 4831 3720 kJ/kg
73.) Accurate Accurate 2230 3710 kJ/kg
74.) Hodgdon Retumbo 3710 kJ/kg
75.) Hodgdon US 869 3700 kJ/kg
76.) Vihtavuori N170 3700 kJ/kg
77.) Accurate Accurate 2460 3690 kJ/kg
78.) Vihtavuori N120 3650 kJ/kg
79.) Vihtavuori N133 3650 kJ/kg
80.) Vihtavuori N160 3650 kJ/kg
81.) Hodgdon H1000 3630 kJ/kg
82.) Vihtavuori N165 3600 kJ/kg
83.) Vihtavuori 20N29 3580 kJ/kg
84.) Accurate Accurate 3100 3550 kJ/kg
85.) Accurate Accurate 3100 3550 kJ/kg
86.) Vihtavuori N135 3550 kJ/kg
87.) Accurate Accurate 2700 3545 kJ/kg
88.) Hodgdon Hybrid 100V 3545 kJ/kg
 
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