Barrel wear with Vihtavouri N540

[TonyR]

I am new to this forum, so forgive me if this topic has already been discussed.

I have a 6mm BR Norma with a 1:8 30" Krieger barrel and a Remington 700 action. I have been using mostly 29.1 to 30 grains of Varget with Berger 95 and 105 VLD's and 107 SMK's.

I want to try some slower powders such as VV N540 and N150 with these bullets, but a friend tells me that he experienced un acceptible barrel wear with the VV. I cannot find this problem mentioned anywhere so I am looking for feedback on the barrel wear issue.

Thanks

TonyR

 

[Gman]

I read somewhere on this forum, or BR Central, that the double-based 500 series powders do burn hotter. If this is true, then I would assume the throat would erode faster than with a single based powder. However, I don't have any proof of this.

 

[TonyR]

Thank you for your reply, Gman.

I should have been more specific in my post, but my firend's concern was, as you say, throat erosion from the extra heat of the double based powder.

 

[expiper]

Hi Tony....I think a lot of folks tell u-n-me a lot of things that they either read in a book or heard on the internet,,there is a lots-0-talk about flame temps,flame propagation,burnig rates,,yada,yoda,yadi...I have one bbl that I used a lot of 540 in,,at least 500rds)) during its infancy,along with just bout every other powder known to man...and every bullet from 60 to 108 gr..just about everything that I tried worked. Now that bbl has 2,800 rds on it and still shoots good enuf that if I have the opportunity to go to the 600yd nats. this april,it WILL be on one of my guns...the last 1500 rds have been mostly Rx-15,which is a double base powder also) and the throat has moved .020 since new,,and the groups are still good enuf for me.
I think the way we cean our bbls,,or dont clean)) is more important than what powder is used. OBTW...If I can get any powder to work in any of my guns I dont care if it is single-double-or triple base..or even has a lil powdered bat wing in it..I will use it ...If you have a bullet/primer/powder combo that will put em in a lil' tiny knot at the target shoot it with all the skill you have.....Roger

 

[expiper]

HI Lynn...ur rite ...that bbl is a lot smarter than I am!!!hahah...so is my recoil pad...Im just a ole' hillbilly and the only tuner I know how to use is the one to get the 6:00 oclock news with!!!,,,maby some day I will try one,,but4 now I gotta keep it simple...Im gonna let the old horse,bbl) lead me to the water....say Hi to DAD,,,,Mike called a while ago..he is fine,,,whew!!)........Roger

 

[TonyR]

Thanks to everyone who commented. I am trying to find what works best in my gun by testing different things, and I will no doubt use whatever works best regardless of the barrel wear.

I start to get signs of excessive pressure with 30 grains of Varget at the end of a 15 or 20 round string as the gun heats up. I am shooting F-Class so I am interested in how the load behaves with a long string in addition to the usual concerns about SD and ED. The 107 SMKs get up to around 2900 and the 95 Beger VLDs to 3000+ with that load after 10 rounds on an 85 degree day shooting in the shade. I like the velocity, but the SD and ES are more than I want and I would be concerned about how these loads would behave on a 90+ degree day or shooting in the sun instead of under a shed even if the dispersion was OK. I am hoping I can keep the velocity while the reducing the other things by switching to a slower powder.

I am planning to work my way down through some of the slower powders. I have some RL-15, N540, and H4350 which seems to be the right sequence from faster to slower.

Gman, thank you for the lead. I did find an old thread on Benchrest Central where a few people speculated about what might happen, but none of them seemed to have actually fired any N540.

Expiper, I hope that I am has happy with my barrel after 2800 rounds as you are with yours. I am sure I can figure out whether my gun likes N540 in less than 500 rounds so your perspective is very helpful. Good luck at the nationals.

Lynn, I have some H4350 for my 6.5-284. I was going to try some N150 after the N540 and H4350 seems to have a similar burn rate. Thanks for the suggestion. One less thing to buy.

 

[GermanS1]

Tony, modern double-base powders like N540 and the Reloder series have additives which bring erosion in line with single base powders. I use a lot of both types and haven't seen any additional erosion in the barrels used with double base powders in 6BR - I'm close to 4000 rounds in one of them and it's still doing very well.
I'm a prone shooter, so like you, I will go about 70 rounds before cleaning, this doesn't present any problems; my last 20 shots are as accurate as my first 20. I use moly coated bullets, which I believe helps maintain accuracy for the 70 shots, but in any event, the double base powders don't behave any less accurately than the single base in this regard. Temepratures here in Phoenix are pretty warm about half the year and that hasn't been a problem either. I take care to keep all ammo out of direct sunlight, however.
As expiper and others have said, find the powder that shoots best in your rifle and use it. In any event, barrels are as expendable as bullets,cheaper too, think about it).

 

[Travelor]

I use VV 550 in my 6mmBR and find I get better velocities and less pressure than Varget.

One of the service rifle shooters over on Long Rang Shooting states he gets much better barrel life with VV 550 than Varget in his AR.

 

[TonyR]

Thanks to everyone for their comments.
I have ordered some slower powders and some 450 primers and will do some ladders to see what works without worrying about the barrel wear.

 

[jo191145]

Maybe I'm nuts but I believe Viht powders might actually be beneficial concerning barrel wear.
I sure notice the first few patches while cleaning run smoother through the tube compared to most other powders.
Feels like cleaning a tube shot with moly.