What kills barrel life on bigger magnums?

[supercrossbmx69]

What causes the loss of barrel life? Obviously the more the velocity the less barrel life. But lets say the barrel is well cleaned and taken care of, Is it the amount of powder being pushed down the bore?

 

[bigngreen]

Using the trigger as a giggle switch repeatedly! A couple shots then checking conditions and letting things chill will go a long ways!

 

[sdeviation]

Giggle switch ,,,lol,, i like that.
#1 reason in my mind too

 

[MudRunner2005]

Excessive heat and overbore calibers is what kills barrels. It's the nature of the beast and a vicious cycle.

 

[supercrossbmx69]

Bigngreen, thanks for your reply.

Not quite what I was asking, but I still appreciate it!

Here's my dilemma, I have like a day or two to figure this out. I just ordered a LRKM from Shawn. I'm stuck between the edge +p and the terminator +p. the main thing pushing me away from the terminator is loss in barrel life. But here's where I'm confused. In a 30" barrel, Shawn is getting about 3040 fps with 101 gr of n570, Broz in his terminator is getting 3210 fps with 111 gr of n570 (out of a 32" barrel) So obviously the terminator will lose barrel life faster. But what is causing it? The 10 grns more powder? The extra 170 fps?

This is so freakin hard to decide on which case to use!!

 

[Kiwi Greg]

Bigngreen, thanks for your reply.

Not quite what I was asking, but I still appreciate it!

Here's my dilemma, I have like a day or two to figure this out. I just ordered a LRKM from Shawn. I'm stuck between the edge +p and the terminator +p. the main thing pushing me away from the terminator is loss in barrel life. But here's where I'm confused. In a 30" barrel, Shawn is getting about 3040 fps with 101 gr of n570, Broz in his terminator is getting 3210 fps with 111 gr of n570 (out of a 32" barrel) So obviously the terminator will lose barrel life faster. But what is causing it? The 10 grns more powder? The extra 170 fps?

This is so freakin hard to decide on which case to use!!

Both will be a factor in barrel life, more powder, more speed, more heat, all through the same size hole.

Get the 338 Terminator +p & don't look back

 

[bigngreen]

How you shoot each will make the big difference, where the powder burns makes a difference, the Lapua case being larger may let more powder burn in case, I honestly think at this case capacity you won't see much of a difference between the two. I've shot Jeff's a few times, between the performance and the Lapua brass when I order mine it will be the Terminator without a doubt!

 

[supercrossbmx69]

Yea I haven't shot Jeff's but I watched him shoot it at 2k I think it was. And I had to have one!! The wait is going to suck!! But I should have a 338 raptor to play with until then, in the next few days hopefully!!! Alright you guys talked me into it!

 

[royinidaho]

Good discussion.

Question on how to get more, if not all, of the powder to stay/burn in the case. That is not in the throat.

I doubt that it is possible. Just sayin'. Not knowin'.

At least some consideration, though I don't know how much, should/could be given to the abrasiveness of the powder. As in stick vs ball. Ball 'should' erode less???

I did a bunch of "forward ignition" experimenting with flash tubes just short of the bullet base.

Observations were:

Felt recoil was lessened.
First 4-6" of barrel got way hotter way faster
Heat signature then proceeded down the barrel to the muzzle. Took some time but muzzle temp increased significantly.
Using RSI pressure gizmo showed noticeable change in pressure curve.
ES went way down
Launched many copper tubes down range.:roll eyes:

Higher bbl temp near chamber end plus inability to adequately secure flash tube in flash hole dampened the project.

Major problem was that my loading pressures were excessive to begin with thus case head expansion loosened threads too much.

Got 900 good hot loads out of the barrel. Only a few were with flash tubes.

Me thinks temperature along with pressure is the main culprit of barrel erosion.

Highly recommend using these extreme magnums for game taking not trigger tickling.

 

[Mikecr]

temperature along with pressure is the main culprit of barrel erosion

I agree with this, and remind that it's relative to area applied(of bore/groove), and added to existing temperature(of bore/groove).

Speed means nothing with barrel life. They don't really wear out, and even erosion is not the ultimate/irreversible killer of barrel performance. Afterall, you can set back a barrel several times to renew shooting performance.
What ends it, is bore/groove constriction. This due to carbon buildup, or moly buildup, and/or lifting of bore surface from heat damage. Once these arrive, they can't be undone without damaging the bore as much.

Let a barrel cool a bit between shots(~45sec),, don't let anything build up in there.
Use less powder,, cooler powder,, rational pressures.
Also, the 500series VV powders are the very hottest of powders out there. These are the last powders you would want to use if barrel life is really a concern.

 

[FEENIX]

Q: What kills barrel life on bigger magnums?

A: Most often than not, it's the nut behind the trigger. gun)

 

[Kennibear]

supercrossbmx69

Every thing said so far is sound advice. The actions of the shooter do more to kill the life of the barrel. But the question should probably be: How do I maximize my barrel life?

The difference between the two, 11 grains or so, doesn't really affect barrel life at these extremes. Some but not much. So my $0.02:

1) Overbore cartridges benefit greatly from increased barrel length. If you consider the lesser cartridge with 4" more barrel you could achieve the same velocity (or there about).
2) Ball powder has shown to lessen barrel erosion over tubular powders. Tested by the D.O.D. in machine gun barrels. Triple based powders also reduce wear, specially in cannons.
3) Bullet type and construction counts. No way us mortals can determine that. Boat tails cause more erosion than flat base.
4) the M60 barrels came with Stelite chambers to last longer. Barrel steel makes a difference but for this I put my faith in the barrel maker. Their recommendation would be Gospel for me.
5) Cleaning adds life. Over cleaning subtracts life. I clean but count on the bore solvent to cut the crud. Rod guide obviously. Rods can destroy a barrel throat in short order. But clean barrels last longer. I tried Barnes CR10 yesterday. WOW!
6) Break it in. Ask the barrel maker how. If they tell you to shoot the first three rounds while tap dancing in a tutu I would consider it.

royinidaho did what others have tried (P.O. Ackley et al). Artillery shells use flash tubes, but are not reloaded. It works, with complications. But then television was invented in Idaho too! (Farnsworth) If I could I would!

Pick a cartridge of choice. But whatever it is treat your barrel right and figure you only have a fixed # of rounds to get 'er done.

KB

 

[Hired Gun]

The only thing that beats a long heavy bullet at long range in the wind is a faster long heavy bullet. 170 FPS is a big difference. Get the faster one. If you want to drive it like a little old lady you can always load it down. I only wish I had the time and money to wear out a barrel.

If it was for me I would want it in a Chey Tac based 338. That will get the show on the road.

 

[Fiftydriver]

What causes the loss of barrel life? Obviously the more the velocity the less barrel life. But lets say the barrel is well cleaned and taken care of, Is it the amount of powder being pushed down the bore?

Pure and simple, bore temperature kills throat life. It really does not matter how much powder you burn in a chambering or how little, its how hot the barrel is and if you continue to shoot the rifle that will determine how long or short your rifle lasts.

Some of my wildcats are pretty extreme but if you keep the barrel cool and clean, they last for a suprising long time. On the other side of the coin, if you take a chambering with much less capacity, get the barrel hot and keep shooting, it will erode a throat much more quickly then a larger capacity chambering that is properly used and cared for.

Muzzle velocity has very little to do with bore wear.

Powder type also has very little difference. In the end, its how hot the bore gets and if you keep shooting the rifle. This may mean you need to keep shot strings to less then three shots and allow barrel to cool between each which is exactly my recommendation for all my customers using my extreme performance rifles.

Simply comes down to keeping the bore clean and most importantly, keep it cool.

Now, some barrel steels withstand barrel wear better then others. The harder stainless steel in cut rifled barrels tends to offer slightly longer throat life then a button pulled barrel.

Throat design also is a factor. The tighter the throat and to some degree, the shorter the throat, the longer the accuracy life of a barrel will be but again in the end, bore temp while firing is BY FAR the most important factor in barrel life.

Keep em clean and cool and they will last much longer then most would ever believe.