Average throat wear?

[steve123]

Does anybody know what would be the average throat wear per 100 rounds shot for 105-115 6mm VLD's running around 3100fps?

Maybe this cannot be answered accurately because of the many factors involved,so how much has yours worn?

Guys with other calibers feel free to share yours also.

Steve

 

[Victor N TN]

Re: Average throat wear?

Check your chamber with a max length cartridge and measure it. In 100 rounds do it again. <span style="font-weight: bold">For repeatability use an ogive comparator instead of OAL. </span> You probably won't get a good readable figure until you pass 4 to 500 rounds. A lot will depend on the powder you're using. Some tend to burn the throat slightly more than others.

In the past I have had as much as .003" in 500 rounds. I extended the bullet seating length and the groups came back together.

 

[kyreloader]

Re: Average throat wear?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Victor N TN</div><div class="ubbcode-body"> A lot will depend on the powder you're using. Some tend to burn the throat slightly more than others. </div></div>

Is this conjecture or is this known? If so, what powders are known or have been shown to burn the throats faster?

 

[ChrisGarrett]

Re: Average throat wear?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kyreloader</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Victor N TN</div><div class="ubbcode-body"> A lot will depend on the powder you're using. Some tend to burn the throat slightly more than others. </div></div>

Is this conjecture or is this known? If so, what powders are known or have been shown to burn the throats faster? </div></div>

Higher energy powders will burn hotter and eat away the throats faster than lower energy powders, powder denisty/weight being equal.

The VihtaVouri 5xx series of powders comes to mind.

Also, I've read that throat errosion (TE) for any cartridge is a function of bore diameter divided by powder charge in pounds, IIRC. Smaller calibers with lots of powder will do more TE harm than bigger calibers with not a lot of powder, or as much powder.

Chris

 

[steve123]

Re: Average throat wear?

I'm getting a new Schneider barrel here in a couple weeks.This time around I'm going to do some careful measuring to find out how much the throat is wearing.

The barrel that was on the gun before had about 500 rounds through it when I bought the gun.I found a load that worked well and 2000 rounds later the throat was worn way forward.

Steve

 

[ChrisGarrett]

Re: Average throat wear?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: steve123</div><div class="ubbcode-body">I'm getting a new Schneider barrel here in a couple weeks.This time around I'm going to do some careful measuring to find out how much the throat is wearing.

The barrel that was on the gun before had about 500 rounds through it when I bought the gun.I found a load that worked well and 2000 rounds later the throat was worn way forward.

Steve </div></div>

I shoot both a 7 RemMag and 338 Lapua Mag, so both of those are notoriously tough on the throats of barrels.

I always tell people here to load to the distance you intend to shoot. No sense loading hot if you're not going to stretch it out. Besides cutting down on recoil and gun powder, you save your throat a bit.

Chris

 

[SuperXJeff]

Re: Average throat wear?

Well and not to mention there is no point on earth of shooting any kind of 30 cal magnum unless you are going to shoot pretty far. The idea of loading a 300 Win mag down to 30-06 velocity is asinine. yet I see guys do it all the time.

2500 rounds and the barrel ( throat) was shot... Lets see... Was it a 6.5x284? if you bought it from your best friend you know that it had 500 rounds fired through it. anybody else and round count becomes suspect. There are hot calibers that burn up barrels in 2500 rounds but not that many. That said if it only lasted 2500 rounds it may have lived up to it's average barrel life. I can tell you for a fact that lots of barrels are sold as excellent shape pull offs that have had 1500 hot shells fired through them as a Hawkeye bore scope will show you that in a hurry. Trouble is most of us do not own one. Your caliber will determine throat wear and I suspect the more overbore a round is, The faster the throat will burn up. Anytime you burn an extra 20 -30 grains of powder to get 100 feet per second that heat has to come from someplace.


A guy can have an awful lot of fun burning up a barrel. A good barrel is like a good dog. You love it but you know that you will most likely outlive it and have to get another and you fear you will never find one as good as the last one! Jeff

 

[steve123]

Re: Average throat wear?

Chris,

First thing I'll do is find the higher accuracy node for velocity via ladder testing at 300 yards.Then adjust seating depth.I'm pretty sure it will be about the same as my last barrel,maybe not,who knows.The velocity the gun and bullet likes best will be what I use.

These darn 6x47L's are capable of insane velocities without a sticky bolt.I was able to send 105's to 3300fps before the bolt got sticky.I shoot tactical matches and I need a load that shoots good at 100Y and 1000Y.I'll find a load that is acceptable for all scenarios.

So I've excepted the fact that I have to pay the price for speed.A new barrel every year and half or so.

Thanks for your advice.Have you any idea how far the throats have worn forward on your rifles?

Steve

 

[steve123]

Re: Average throat wear?

Jeff,

Haha,I've got a big 30 that sends 240's at 2925 fps.No loading down too much for me.

No I'm not exactly sure the barrel had 500 rounds through it but he's an honest sort of guy.

That's funny that you mention 6.5-284.I had a new Krieger 6.5-284 put on my 1000Y benchrest rifle to try first a couple years ago.It lasted 1200 rounds.So at 2500 rounds through the 6x47L I'm feeling good!That same gun now has a 6x47L barrel on it.

How much wear do you guys get on the throats of your rifles from new to worn?

Steve

 

[kyreloader]

Re: Average throat wear?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ChrisGarrett</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kyreloader</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Victor N TN</div><div class="ubbcode-body"> A lot will depend on the powder you're using. Some tend to burn the throat slightly more than others. </div></div>

Is this conjecture or is this known? If so, what powders are known or have been shown to burn the throats faster? </div></div>

Higher energy powders will burn hotter and eat away the throats faster than lower energy powders, powder denisty/weight being equal.

The VihtaVouri 5xx series of powders comes to mind.

Also, I've read that throat errosion (TE) for any cartridge is a function of bore diameter divided by powder charge in pounds, IIRC. Smaller calibers with lots of powder will do more TE harm than bigger calibers with not a lot of powder, or as much powder.

Chris </div></div>

Conceptually I can see that as the case, but I have yet to see this documented or compared. I have also read where slow powders are easier of the throat, but again conceptually I could understand but have yet to see if documented.

My question is has anyone (highpower shooters maybe), shot out 1 barrel with N133 then shot out another barrel with N530 and compared the round count for example?

Or, has any 6.5x284 shooter shot out a barrel with H4350, then another with H1000 and compared the round count for example?

300 WM shooter, shoot out a barrel with RL 22(double based), then shot out one with Retumbo/H1000, any difference?

 

[DRAM40A1]

Re: Average throat wear?

I shoot the 115 out of a Schneider 6XC barrel. I started .010 off the lands and after 1600 rounds, I'm jumping .042.
I'm only running them 2950 but it has been shot pretty fast at times. BTW, I am using moly.

 

[Victor N TN]

Re: Average throat wear?

I did have a paper (published magazine article) that I can't find right now. But it said that the VihtaVouri powder (N-140) did not burn as hot or cause as much erosion as the Winchester ball powder that it was tested against.They compared They compared 2 each of the Vit powders (100 series) IMR, Hogden, and Winchester. This article was several years ago. My memory is kind of sketchy on the other powders. But I believe the caliber in question was 308. If I remember correctly the finish results were VihtaVouri powders finished first, then IMR, Hogden and Winchester last.

Like I stated earlier the article was several years ago and I won't swear as to exactly what powders were used. But the statements above are the best I can remember.

I hope this helps answer some of your questions.