I was talking with a non AR buddy last night. We were discussing powder choices for my 505 Gibbs. I’m thinking of switching to a slower powder like Reloader 25. He brought up the fact that RL25 is a double based powder and would be harder on my barrel. I’ve heard this before, but as I have never shot the barrel out of any rifle I own I’ve never seen it happen. I’ll usually shoot a new rifle a few hundred times, shoot something with it and then buy a new rifle.

All of this lead to our discussion (argument) over the barrel life of big bore rifles. I’ve read that barrel life (all other things being equal) is a factor of X pounds of powder burned though it. Now I’ve heard of guys shooting the barrels out really of over-bore cartridges like the .220 Swift, .257 Weatherby, .264 Winchester Magnum, etc. etc.

Now I’ve never heard of any one shooting the barrel out of a big bore as fast as the above mentioned cartridges. The .375 H&H holds more powder than any of the ones I mentioned, yet when is the last time you’ve heard of a .375 shot out in a few hundred rounds?

Every time I pull the trigger on my 505 I’m burning 142 grains of H4831. Is this wear and tear on my barrel equivalent to touching one off in a .220 Swift? Would switching to RL 25 make it worse? If this is not the case is there a ratio of bore size to X pounds burned?

Just thought it would be an interesting question to post….

What do ya guys think?

Matt V.

i think that if you shoot that 505 enough to burn out the barrel, you'll need to replace your shoulder as well

that is exactly what I was thinking. If you shoot out the barrel in a .505, you are a HELLUVA LOT more man than me!!!

The main factor affecting barrel life is continuing to shoot with a hot barrel. The flash temperature at primer ignition is approximately 300F and at 55,000 psi operating pressure the peak flame temperature can reach between 5000F - 6000F. Barrel steel melts around 2500F - 3000F. So letting your barrel cool in between shooting strings is key to long barrel life.

Cartridges such as the 220 Swift have very little felt recoil and are used in the varmint field where there are hundreds of targets to engage in a short period. Varmint hunters expect to wash-out barrels, but they don't have expensive quarter-ribs, barrel bands, front sight bands, and secondary lugs to replace with the barrel. Of course, the Varmint hunter may have a dozen rifles along to swap out.

It would be great if big game where so plentiful to wash-out a .500 caliber barrel. No worries regarding your barrel life.

The 505 should have a much longer life than a 50 BMG and you can imagine the use they get just in training, not to mention the heat. I don't believe barrel life should be much of a concern. Just shoot-em as much as you can and enjoy.R.

Butchloc & Marc,

I agree, I don’t think it’s humanly possible…..

Buliwyf & Rodney H,

I also agree…. I always let the barrel cool down between shots. I’m in no way worried about shooting my barrel out on my 505. I’ll probably shoot it 300 – 500 rounds in my life time.

But let’s say we were to do a scientific experiment;

Take the human factor out of the equation, put two rifles in machine type rests…….

Let’s say a .264 Winchester Magnum and a 460 WBY....

These are both relatively high pressure rounds…

Let’s use RL 25 (or some other double based powder) in each cartridge and push them to the max…..

But the 460 will have around double the charge of the 264 (this may not be exact, but humor me)………

Pull the trigger every 30 seconds…….

Which cartridge will shoot its barrel out first?

Matt V………

I belive the answer is "volume" related. An efficient cartridge like the .257 Roberts AI burns the right amount of powder creating the right amount of gas volume to push the bullet out the bore at peak velocity.

If a caliber requires large increases of powder to get minimal gains in velocity it can be considered "over-bore". The .264 Winchester Magnum(and similar cartridges) has a much higher caliber over-bore ratio than the .458 caliber so the .264 Win Mag would wash out first.

This is of couse a simplified response.

I agree....

Barrel life cannot be just a product of pounds of powder burned relative to all cartridges..

Bore volume has to have something to do with it...

Just look at what happened when Rob necked down the 600OK to 375....

I was thinking along the lines of 50BMG vs 505Gibbs in identical barrels including contour and twist. I believe the 505 would outlast most any of the fifties including the jeffery chambering. But I was considering chamber pressures and average velocties of these two. I agree that there is more erosion with larger powder charges. So I would have to think a little on the comparison you proposed. I only wish I could afford to wear out a 505. R.

I have only shot the barrels out of three big bores, one 416 Rigby and two 458 Win mags.

The Rigby took about 1000 rounds (hot Weatherby level rounds).

The 458 Winnies took a couple thousand each. The M70 was truly abused with as many as 100 rounds fired in 1.5 hours (yes it was HOT).

The 50 Beowulf on the other hand may have had as many as 300 rounds poured through it in a couple hours of fun and survived over 3000 rounds with no perceivable degradation.

I reckon your average big bore barrel;

.416, .375, .458's and various .500's and the .505 Gibbswould be good for 1500-2000 shots thats my guess.

quote:

Originally posted by ScottS:
I have only shot the barrels out of three big bores, one 416 Rigby and two 458 Win mags.

The Rigby took about 1000 rounds (hot Weatherby level rounds).

The 458 Winnies took a couple thousand each. The M70 was truly abused with as many as 100 rounds fired in 1.5 hours (yes it was HOT).

The 50 Beowulf on the other hand may have had as many as 300 rounds poured through it in a couple hours of fun and survived over 3000 rounds with no perceivable degradation.

What tipped you off? key-holing, low velocities, poor accuracy?

All I have to say is that it is clearly more rounds than I care to shoot out of one!!!

quote:

Originally posted by ScottS:
I have only shot the barrels out of three big bores, one 416 Rigby and two 458 Win mags.

The Rigby took about 1000 rounds (hot Weatherby level rounds).

The 458 Winnies took a couple thousand each. The M70 was truly abused with as many as 100 rounds fired in 1.5 hours (yes it was HOT).

The 50 Beowulf on the other hand may have had as many as 300 rounds poured through it in a couple hours of fun and survived over 3000 rounds with no perceivable degradation.

Hmmm, based on past postings, my bullshit meter was just pegged.

PaulH,

bent the needle here too! Soon as I saw the signature I expected something like that!

My money says about two rotator cuff surgeries per 505 Gibbs barrel, maybe three.

Try about 120 grains of VihtaVuori oy N 160. Ran a 650gr bullet right at 2200fps for me.

regards,

Rich
DRSS
505 Gibbs shooter

/

ptaylor,

Reduced accuracy. Gunsmith explained the Rigby to me as I hadn't thought it was that bad, but I was wrong. The Winnies degrade from 2 MOA to ove 4 MOA when I had the barrels inspected.

I really don't get the shoulder comments, my head always fails before my shoulder (long long before my shoulder).

most persons can't shoot out a bigbore rifle... period...

Alf's chart makes that pretty clear, huh?

SOME people think that their sloppy shooting is as a result of profound flinch the gun being worn out

quote:

Originally posted by ScottS:
I have only shot the barrels out of three big bores, one 416 Rigby and two 458 Win mags.
.

yeah, okay scotty...

I'm not particularly recoil sensitive and I like big bore rifles but when shooting at the range,I find that I shoot a hard recoiling rifle much better if I let a bit of time elapse between shots.I find that groups start to open up if I do otherwise.

For me,at least,that seems to automatically void out the overheated barrel issue.

I have never owned one but I hope they are not anything like black powder rifles that lose their accuracy in short time without any apparent reason.

Speak for yourself Jeff. The barrel throats were badly erroded on those rifles, particularly the Rigby. Sorry but bore scopes don't lie. None of the rifles were ever overly accurate, the 458s started out around 2 MOA (we won't discuss shooting cast in them at velocities over 1800 fps) and the Rigby was an honest 2.5 MOA rifle. They degraded rapidly as they got to the shot levels I stated. Now don't get me wrong they had rifling in the barrels, so if a smooth bore is your definition of shot out, they certainly would not have qualified under that definition.

The only rifle I have ever owned that keyholed was a M1896 Krag Springfield custom that had God only knows how many rounds through it's military barrel, and it had rifling left too.

Regarding Alf's chart, personally I think it is over generalized. Perhaps it is referring to the number of shots necessary to have a smooth bore. To through one wrench into the system I have two 303 barrels and one 30-06 barrel both of which aren't shot out and far exceed the shot levels that Al'f chart says they could go The 303's have 5000+ rounds on them (Alf's chart says 4000) and the 30-06 also has 5000+ rounds on it (Alf's chart says 3000). Go figure. All three of those barrels have some throat erosion, but not enough to significantly affect accuracy (and they get real hot when shooting too).

Got a 30 Carbine that probably has 30,000+ rounds through it, is nearly a smoothbore, and still shoots 2.5 MOA all day (which happens to be about as good as I can shoot with it's peep sights). That rifle really throws a monkey wrench in Alf's chart.

ALF,

Thank you very much for the chart…….it is very informative…..

So it appears I guessed correctly……

For any given powder as bore size increases so does barrel life……and slower powders are harder on any given bore size……..

I guess it is sort of like a water hose, the finer the stream the more cutting effect it has…..

Matt V.

Doesn't the barrel composition have an impact on barrel life?

I am remembering WAY back now - when the US military was specing out sniper rifles. One of those specs was that the rifle barrel remain accurate for 10,000 rounds. The caliber, at the time, was 338 Lapua.

As I recall, the only manufacturer that met that particular spec was Accuracy International.

Also, doesn't higher velocity have a big impact on barrel wear? Higher velocity = more friction = more heat?

Well I have burned the barrel out of 2 .50BMG's K&P and Pac-Nor SS. Both shot heavily in competition. By 1200 rds they were toast through and through. I'd imagine since your burning half the amount of powder in a .505 Gibbs that a barrel should last 1800-2500 rds. I think of it as a large plasma torch. The hotter the burn, duration, and diameter of the bore all combine to cause metal corrosion and flame erosion. By the way, the muzzels of both guns showed a curious funnel effect of the corrosion. I used to cut the barrel back 1 inch each 500 rds and re-crown each time I saw a drop off in accuracy. It worked.
I suspect the .375/.600OK will have a usefull barrel life of about 200 rds. I can alredy see some corrosion. -Rob

ok, scott...got the name and phone number of your gunsmith handy? Care to post a picture of any of your rifles laying on today's dated newspaper? Not that we all believe you are a lying sack of monkey dung or anything...ok, we do! Prove us wrong!

Maybe, Judy, or Axel or Poseur can do it for you.

regards,

Rich
DRSS

Didn't Harry Selby have his .416 Rigby Mauser rebarreled due to wear? Or was it for some other reason?

A friend had a 30-06 and he said the barrel was shot.....said he had 6,000 rounds thru it.....He wanted a new Douglas barrel installed so I put one on for him and he was happy.

I kept the old barrel as after I cleaned it well it looked like new.....absolutely no signs of wear or erosion at all!!!!!

In short......there are always a few guys that somehow just think they need a new barrel.

I also had a friend that bought a new barrel for his Remmy 870.......he said the old barrel was getting paper thin!!!!!!

Where's that bullshit meter?

Vapo,
I think this thread wore the meter out!!!

quote:

Originally posted by ireload2:
Vapo,
I think this thread wore the meter out!!!

I see that!!!!!