I've been noticing here and there discussions about barrel life. I was wondering which of the popular US cartridges have good/bad barrel life. I know my WSM did. Do all magnums have short barrel life?

Barrel life has to do with several factors . IMO Grade of metal and heat treatment is Important in barrel life as well as accuracy ; The first and most important " Wear Factor " is Velocity which = more powder to propel the projectile down the barrel causing increased friction , coupled with hot erosive gases from Primer & powder burn. A clean bore has little to do with wear again IMO . Think of fouling as a cushion of sorts . Now to much and problems occur, not enough accuracy falls off .

How ever a fouled bore isn't the same as a pitted or shot out bore or Dirty Bore !.

Shoot Straight Know Your Target . ...

Soooo its high velocity that wears out barrles?

quote:

Wear Factor " is Velocity which = more powder to propel the projectile down the barrel causing increased friction

A couple of points here:

First off, it isn't the barrel that wears out but the throat of the barrel which is slowly eroded away until accuracy becomes unacceptable.

Secondly, if has little to do with friction but more to do with the temperature and pressure caused by the burning powder.

The important thing is the amount of powder burnt in a given barrel volume ie; a 7mm-08 shooting 140 grainers with 45 grains of powder will have a much longer life than a 7mm Rum shooting the same 140 grainers with 90 odd grains of powder.

I agree with Tumbo.. that is why I use mid range powders like IMR 4895, 4064, 3031, RL 7 and 15, W 748 when ever I can...

I read an article once on barrel life for accuracy... it mentioned the same thing, how much powder is burned down the barrel...

a 300 Ultra Mag was given a life span of 300 to 500 shots before accuracy deterioriation... where as the average 30/30 was listed having an accurate barrel life of 10,000 plus rounds...

Light powder charges with faster powders in a bolt action 223, I traded off a Ruger VT that had roughly 15,000 rounds down the barrel.. and it would still put a dime sized group at 100 yds...

about 2/3s of its life it had loads of 12.5 to 14.5 grains of Blue Dot shot thru it......

On a varmint rifle, not heating them up hot enough to brand cattle also works wonders on barrel life...

a local gun smith who does alot of work with ARs for special police and military applications, answered my question about Barrel life on a 223 barrel... he stated 10,000 rounds for accuracy.. about 20,000 for Army field use...

ya wanna guess how many rounds have gone down a barrel.. a few summers ago at Boy Scout Camp they had a couple of 1930s vintage single shot bolt action 22s on the rifle range.. none of the boys were qualifying for their merit badges with those 2 rifles.. we pulled them off the line and I looked at them with a bore scope...

both had about 4 to 6 inches of throat erosion down the barrels.... imagine how many bullets had been down a single shot 22 for that to have happened?????

Seafire2,

I always thought a .22 LR barrel lasted forever. Could improper cleaning been the cause?

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Originally posted by seafire2:
I agree with Tumbo..

As to the .22 rimfire barrels I'd have to agree that the biggest loss of barrel life is improper cleaning and lack of it.....RUST being the prime cause of brrel life loss.

Well Boys, the throats being washed out on those two rifles....

all I can say, is that they have been used extensively at Boy Scout camps for the last 65 to 70 summmers and shot extensively....

even tho each boy is given 5 bullets each time he shoots, and the rifles are single shots... each one can go thru 350 to 500 rounds in a day.. 5 days a week... for 6 to 8 weeks every summer... for about 6 to 7 decades....

Scouting clean the crap out of the barrels on any range I have seen as they teach the kids that... a hard clean at the end of each day, by bored range staff....

As I say, it is mind boggling on how many rounds that those rifles have seen down the barrel....

say 300 rounds a day.... for 40 days a year...equals 12,000 rounds each summer....

12,000 rounds times say 65 summers...780,000 rounds!

o9r 400 rounds a day, for 40 days a summer...equals 16,000 rounds each summer...
x 65 summers....1 million 40 thousand rounds....

I'd call that some high mileage barrels!!!

quote:

Originally posted by Wayfaring Stranger:
... Do all magnums have short barrel life?

Originally posted by Wayfaring Stranger:
..Soooo its high velocity that wears out barrels?

Typically speaking magnums will burn barrels out faster right? that is, with conventional technology. ie;typical jacketed bullets and typical rifling geometry.
Introduce components like polygonal bore barrels,17-4grade SS, and drive banded bullets like GScustomHV design, and things change.
With such you can have a magnum chambering with barrel life that can match or exceed a std chambering that uses std.technology bullet/conventional bore.

Why? cause bullet to bore seal is an important factor. Prevent those hot gases from licking up around the sides of the bullet and you increase service life.
Would you expect a good accurate barrel after 3000 rounds through a 220swift barrel@4400+mv?
http://www.gsgroup.co.za/22x64.html

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Don't keep us in suspense ALF, what did your research point to as being the major factor in barrel wear? Did you reach any conclusions as to ways to prevent wear, or at least reduce it?

I've heard that shooting a hot barrel, i.e. firing a significant number of rounds in a short time period is bad, did this match up with your research?

So many questions, so little time.

Listening intently for the results of AlF's stude re: magnum vs std cartridge barrel life...

quote:

Originally posted by Tumbo:

quote:

Wear Factor " is Velocity which = more powder to propel the projectile down the barrel causing increased friction

A couple of points here:

First off, it isn't the barrel that wears out but the throat of the barrel which is slowly eroded away until accuracy becomes unacceptable.

Secondly, if has little to do with friction but more to do with the temperature and pressure caused by the burning powder.

The important thing is the amount of powder burnt in a given barrel volume ie; a 7mm-08 shooting 140 grainers with 45 grains of powder will have a much longer life than a 7mm Rum shooting the same 140 grainers with 90 odd grains of powder.

So the way I read this, a 300 WSM should have better barrel life than say a 300 RUM, 300 WBY or even 300 WM?

Like others have already so much as said.

You are far more likely to ruin a barrel by improper care than actually succeed in shooting it out.

quote:

So the way I read this, a 300 WSM should have better barrel life than say a 300 RUM, 300 WBY or even 300 WM?

Almost, but not quite. A factor no one has mentioned is pressure. The gas temperature, thus the "blow torch" effect on the leade, increases with pressure. The WSM series is factory loaded (and typically hand loaded, also) to somewhat higher pressures than most other centerfire cartridges. Five hundred rounds at 65,000 PSI might cause as much throat wear as, say, 1,000 rounds at only 52,000 PSI. So, the pressure has to be factored in (although I know of no formula that will accurately predict functional barrel wear).

Some might point out that the Weatherby cartridges have always been loaded to similar pressures as the WSM. This is true, but Weatherby's start out with a worn out throat -- that is no throat at all due to the inch or so of freebore.

FWIW: I have a .264 Winchester (supposedly an infamous barrel burner) that is more than forty years old and must have several thousand rounds through it. The first inch or so of throat looks like it is wallpapered with alligator skin, and it requires a grain or two more powder than it did when new to attain the same velocities. By any measure, this is a "burned out" barrel. Funny thing is, it still shoots MOA and always places the first shot from a cold barrel at 12 o'clock two inches high -- right where it did "last year" (for the last 15 years) when I checked the zero before heading to the hunting pasture.

HOWEVER, my very old gun is an exception in terms of the number of rounds through it as I bought it as a teenager and it was my only hunting rifle for the first twenty years. As a youngster I would also use it as a sort of "plinker" and shoot ground squirrels, rabbits, coyotes, and any other target of oportunity, even rattlesnakes. As a budding handloader, I had to try out every bullet and most available powders. All of this adds up to several lifetimes of "normal" shooting down the bore of this gun.

My point is, that a game gun typically is fired so much less that even if it is prone to wear the barrel in only a few hundreds of rounds, that is usually irrelavent as it will typically outlast the owner, anyway. So, unless you have some reason to do high volume shooting with your hunting rifle you can disregard "barrel life" as a factor, and like our National Debt, let your great-grandchildren worry about it.

Barrel life is just that ; whether it's chamber eroded or throat eroded , the barrel is gone either way .

Seafire statement .
ya wanna guess how many rounds have gone down a barrel.. a few summers ago at Boy Scout Camp they had a couple of 1930s vintage single shot bolt action 22s on the rifle range.. none of the boys were qualifying for their merit badges with those 2 rifles.. we pulled them off the line and I looked at them with a bore scope...

both had about 4 to 6 inches of throat erosion down the barrels.... imagine how many bullets had been down a single shot 22 for that to have happened?????

Now HOW is the above statement in fact accurate ? With out friction as a wear factor . Seeing as most all 22 rim fires are lubed lead and well under Erosive gas temp. , Low velocity as well as pressure ???.

As I stated earlier a " Number of Factors " contribute to barrel life or lack of it .
I simply saw no reason to mention Pressure , as it's a result of increased powder capacity . There for it's the number one contributor to erosive gas wear Be it chamber or throat.

That is the NUMBER ONE barrel eater !. Armor Piercing or Steel jacket Ammo is # 2 , Dirty Bores # 3 , # 4 Projectiles of copper jacketed types , # 5 lead projectiles and last but not least CLEANING . IMO any way .

Bottom line ; Barrels are like tires some wear better than others some handle speeds wet roads others off road terrain .

How ever they ALL WEAR OUT !.

Shoot Straight Know Your Target . ...

Interesting. It seems though, that as a rule standard calibers don't wear out barrels as fast as magnums, correct?

THe reason I ask is I'm building a custom and I plan to shoot and hunt it ALOT. So I was thinking of getting it in a standard caliber as opposed to a magnum, to get the most life out of it for the $$ I'm plunking down.

Hi All, Having recently worn out a barrel (it took 20 years) I will describe how it went. The rifle is a Ruger M77 mk1 in 338 Win Mag. Up to somewhere between 4000 and 5000 rounds, I noticed no deterioration in accuracy, and could not detect any erosion looking down the barrel from breech end with the naked eye. After that , say around 4500 rounds when I cleaned the rifle I started to notice that the bronze brush was a bit looser in the breech end and for a few inches into the barrel. This was more noticable with an older brush that had worn down a bit. Not much accuracy deterioraton was experienced. This rifle typically shot 1.5 MOA with good quality handloaded bullets, it was never a tack driver. Over the next 500 or so rounds the looseness of the brush in the bore worsened until it was quite noticably looser for about 6 inches up the bore. I still could not see much evidence of erosion. I compare this experience to my old .25/06 which lost its accuracy potential with all but the 120gn bullets after 3000 rounds, and where the erosion in the throat was clearly visible. after about 5200 rounds my group sizes started to get a bit big (eg over 3 MOA), and I one day missed a target at the range. I fired a few more shots with the same result, wondering what was wrong, I eventually went up to check the target, and found one sideways 338 bullet hole in the target frame. The rifle went from shooting OK to not at all in about 200 rounds. I could still shoot the longer heavier bullets, but after another 100 rounds or so, even they didn't shoot. So my barrel didn't end up with much visible erosion, but the barrel finished up tapered, and the taper was very noticable (ie when using a cleaning brush) and extended about 1/2 way up the barrel by the end. I think the rifling was so worn in the end that it wouldn't engrave the bullet and didn't impart the correct spin. This was very different to my experience with the .25/06. Perhaps the smaller calibers are more prone to throat erosion as the powder has to funnel into a smaller bore. The rifle is with my gunsmith at the moment getting a new Lothar Walther barrel fited, so it should shoot better than new when I get it back.

quote:

So the way I read this, a 300 WSM should have better barrel life than say a 300 RUM, 300 WBY or even 300 WM?

A 300 WSM should have significantly more life than a 300 RUM simply because the RUM burns 20 + grains of powder more than the 300 WSM and both have the same bore volume.

The 300 weatherby can use about 10 grains more powder than the WSM so the difference in life shouldn't be as big as it is with the RUM.

The 300 WSM and Win Mag use a simular amount of powder, so their barrel life should be simular if used under the same conditions.

Heat is a significant factor in barrel wear, so allowing the barrel to cool between shots should help extend the life of your barrel.

This is subject I sort of enjoying exploring and hearing peoples experiences....

first, 338 User.. welcome to the forum...

As I have seen in rifles I have had that ended up with 'barrel wear' over the years.. I have noted that their accuracy can still be more than acceptable.. and kept accurate by changing the loads....

Consider the ranges you shoot at...

Using cast bullet data, or just slowing down the velocity has still made some of my rifles highly "accurate enough' results...

also changing bullet weights or styles helps out also... like in an 06, 180 gr, 220 gr and 150 gr RNs.. kept a rifle shooting accurately...

throttling down the MVs on the 150 grainers and 180 grainers to between around 2200 to 2400 fps also kept accuracy more than acceptable....

certain powders also tightened up accuracy.. but then they also slowed velocity.. like Sr 4759 and Blue Dot in the 06...

for a shot out 223 barrel, H 335 at fast velocity seems to stretch out the life span of that barrel also...

Cartridges that are notorious for short barrel life are those that are over-bore, having a disproportionate amount of powder volume (case capacity) that are to be burnt in relation to bore size. Typically these over-bore cartridges run at the highest operating pressures and when combined with powders that yields higher "heat of explosion" values, as measured in kJ/Kg, flame temperatures will be higher, and thus melt/erode the barrel steel quicker, especially with quick successive shooting on the bench. For example here are 2 powders that are being used in the 9,3x62; Hodgdon Varget has a H.O.E. (heat of explosion) of 4,050 kJ/Kg compared to Vihtavuori N135 with a H.O.E. of 3,590 kJ/Kg.
Any gas blow-by situation with a bullet will worsen the torch effect.

Perhaps Alf can guide us through the complexities of chemicals and its resultant structural changes on steel. Also interesting that it now comes to light that boatail bullets do contribute to throat erosion as opposed to the previous view that the use of boatials over flat base bullets enhance barrel life. It would be great if Alf could share some of his research with us.

Warrior

one intresting factor in barrel life I believe is case shape. Yesterday I was talking to a friend who shoots alot of competive rifle. He told me that he notices a longer barrel life out of his ackley improved guns versus the standard caliber. He said he brass life is diminished as the necks burn out. His logic is with the steep shoulders some of the fire that is directed into the opposing side of the neck rather than to the throat as with the standard round.

Also I believe that the some of the rounds of yesterday that were deemed barrel burners ie 220 swift are not nearley as bad now with some of the faster burning powders.

skog

quote:

Would you expect a good accurate barrel after 3000 rounds through a 220swift barrel@4400+mv?
http://www.gsgroup.co.za/22x64.html

One thing I noticed about the test on this website was that they didn't use the same bullet types, or at least they never say they did. I guess I could have missed it, but if they didn't, it seems to me that all these results would be pretty moot.

My apologies. I'm not trying to jack the thread. Just wondering if anyone else noticed this discrepancy.

Those 30s vintage 22s probably shot thousands of corrosively primed rounds, too. I'd sthink that helped start the throat deterioration.

The .264 Winchester Magnum was designed to be the ultimate long-range game cartridge in rifles with 26-inch long barrels so as to milk the last drop of velocity out of it. Initially the cartridge was loaded with a 140 grain bullet to achieve a muzzle velocity of 3,200 fps. Very soon it became clear that its barrel life was much shorter than expected and the cartridge started to wane. Hunters much preferred the 7 mm Rem Magnum, which was later introduced in 1962 and probably still is the most popular long-range caliber today in the USA. The price for high velocity in a small bore caliber is accelerated throat erosion.

Warrior

quote:

one intresting factor in barrel life I believe is case shape.

Sorry; that old urban legend has floated around for many years and always seems to crop up when these discussions take place. Case shape is as irrelavent to barrel life as it is to pressure and velocity.

Lots of varibles, but I believe the main problems that wash out throats is shooting too fast and not allowing bores to cool..Cleaning rods used improperly is another..

I have a friend that has put 5000 plus rounds through his 300 Wby without accuracy loss and yet another who washed out his 300 Ackley Imp. in less than a 1000 rounds.

I also have seen barrels that were awful looking, washed out, pitted, chunks out of the rifleing and they shot like a house afire, so who knows..

My old 25-35 Win. must have had 10,000 plus rounds through it and it looks like the inside of the smokestack of a tramp steamer, so does my grandfathers old 30-30..both will shoot an inch or inch and a half at 100 yards everytime with iron sights, your welcome to try them if you ever in the area..

I gave up on this one many years ago and just take each rifle as it comes, when it quits shooting I will stick a new tube on it.

Why worry about such things that you have absolutly no control over and that don't really make any difference anyway! MOst rifles will outlast the average hunter/shooter anyway.

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The factors that are significant in causing throat wear are:
1. Mechanical abrasion of the bullet material that tears away steel particles,
2. Mechanical abrasion of the powder/gas mass that tears away steel particles and
3. Chemical abrasion through changes ocurring in the composition of the barrel steel.

The factors that are significant as contributory factors are:
1. Increased heat.
2. Increased pressure.

The effect of all of these factors can be increased or reduced in several ways.

Causative factors:
1. Mechanical abrasion of the bore can be increased through increased barrel wall pressure. Examples - By using a jacketed bullet with a soft lead core that expands radially under pressure, the harder the jacket the greater the abrasion, or by using high tensile strength monometal bullets that are over size. Mechanical abrasion can be decreased by using monometal drive band bullets, by a lubricant, and by using under size monometal bullets.

2. Gas abrasion is increased as powder charge is increased and vice versa. Gas abrasion at any level can be reduced by extending the time over which the pressure curve rises, by reducing gas leakage and by the characteristics of the powder that is chosen. GSC drive band bullets are designed to reduce gas leakage to the lowest that it can be and extend the pressure curve rise because of the low engraving pressure. Expanding volume and surface area is created more quickly than with non drive band or grooved bullets.

Under size monometal bullets (including drive band bullets) allow gas leakage at the greatest level of all bullets and, although the pressure curve is also delayed, this merely extends the distance over which the abrasion will take place. Jacketed bullets fall in the middle because, at some stage into the bore, they obturate the bore and prevent gas leakage.

3. Chemical abrasion is accelerated by increased pressure and temperature of the surface of the bore. It is reduced by allowing the barrel to cool a little between shots, reducing the friction of the bullet and by using a lubricant to coat the surface. GSC drive band bullets have much lower shot start (engraving) pressures than any other grooved or smooth shanked bullet. The surface area of a GSC drive band bullet that is in contact with the barrel is less than half of that of a typical grooved bullet and grooved bullets are one step better than smooth shanked bullets. Moly coating, when done correctly, reduces chemical abrasion.

Contributory factors:

1. Heat. Drive band bullets reduce heat through lower friction and by extending the initial increase in temperature over a larger surface area of the bore.
2. Pressure. Ditto.

An unfortunate fact of life is that barrels wear out. Whatever barrel or caliber you choose and whatever the eventual life of that barrel may be, you can extend that number by controlling the way you shoot the rifle and by the components you choose. As always, the choices are yours.

To address the original question: Yes, "magnum" caliber barrels have a shorter life span than slower calibers but magnums can be made to last longer, with the right choices, than slower calibers with the wrong choices.

Alf, I would be interested to see the boat tail / flat base comparison.

Thanks to ALF and Gerard for the details and information, it is all interesting stuff.

As Ray says it is probably best not to worry too much about it and let "nature" take its course but even so it is interesting to know the details.

Anyone who spends some of their time sending a tiny projectile hundreds of yards in an attempt to hit a small dot has to be somewhat overly interested in small details so I guess we all like to know these things even if there is nothing we can do about them.

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quote:

Adiabatic flame temperature of the propellant is the most important factor, more powder means more heat, more heat means more erosion.

To combat this most critical variable in throat erosion, ie high flame temperature, one is better off with calibers with bigger bore diameters that are chambered for cartridges with smaller cases, as that translates to lower pressure levels and lower flame temperatures. That is why the big-cased small bore .264 Win Mag was so notorius for short barrel life. On the other hand, the 9,3 x62 mm is one caliber that meats these criteria rather well when compared with other faster and bigger cased cartridges. The 7x57 mm and the .308 Win are also known for giving long barrel life, largely due to smaller powder volumes to be burnt. Many military and benchrest results bear this fact out with the .308 Win.

Here are some comparisons:

6.5x55 Swedish --- bore size = .264" --- case capacity in water = 57.0 grains --- PMax = 55,114 Psi
260 Rem ----------- bore size = .264" --- case capacity in water = 53.5 grains --- PMax = 60,191 Psi
.264 Win Mag ----- bore size = .265" --- case capacity in water = 82.0 grains --- PMax = 62,366 Psi

7x57 mm ----------- bore size = .285" --- case capacity in water = 59.5 grains --- PMax = 56,565 Psi
7 mm Rem Mag----- bore size = .284" --- case capacity in water = 82.0 grains --- PMax = 62,366 Psi
7 mm STW----------- bore size = .284" --- case capacity in water = 97.0 grains --- PMax = 66,717 Psi

.308 Win ---------- bore size = .308" --- case capacity in water = 56.0 grains --- PMax = 60,191 Psi
30-06 Spr---------- bore size = .308" --- case capacity in water = 68.2 grains --- PMax = 58,740 Psi
.300 Win Mag ----- bore size = .308" --- case capacity in water = 92.0 grains --- PMax = 62,366 Psi

9,3x62 mm --------- bore size = .366" --- case capacity in water = 75.0 grains --- PMax = 56,565 Psi
.375 H&H ----------- bore size = .375" --- case capacity in water = 93.3 grains --- PMax = 62,363 Psi
.378 Wby Mag------ bore size = .375" --- case capacity in water = 137.0 grains -- PMax = 63,817 Psi

The ratio of bore size (area) to powder volume is critical. On this foundation we can do certain things to better the situation through loading & shooting practises and the choice of bullets. For example shooting short bullets in long-throated calibers such as the 9,3x62 and/or overly heavy bullets such as the tough steel-jacketed 320 gr WDL FMJ bullet that drive pressure levels up quickly when pushed for velocities above 2,180 fps fps, as per my pressure tests that will be published shortly.

Warrior

quote:

The factors that are significant in causing throat wear are:
1. Mechanical abrasion of the bullet material that tears away steel particles,

No offence mate, but that doesn't explain how M60 blank firing barrels wear out just as quickly as the normal barrels do ??

I got 3000 rounds threw my 30/06 Shooting 150gr bullets. Witch was pretty good I then had another barrel put on it. For labor and the new barrel cost me in the range of $350.00 With was cheaper then buying another 30/06.

Atkinson is right on this one. Barrel life will be reduced the most from getting the barrel red hot than most anything else. Most average shooters will never live long enough to wear out anything but a varmint rifle barrel. I have a 7Mag that has over 3000 through it, still shoots 3/4 in. I don't worry about barrel life, when they are shot, I buy another one. I have a 7x57 being rebarreled now.

Guys, I don’t see why this subject needs rocket science, just common sense. I think bore wear is quite simple. The more matter you blast over a patch of steel at high temperature and pressure, the faster that patch of steel is going to wear down. A smaller patch of steel will wear out sooner than a larger patch. For example, 300 RUMs wear out barrels faster than 308s when both are shot with the same bullets and at the same PSIs. Moreover, a smaller patch of steel will wear-out sooner than a larger patch of steel, everything else being equal. With large bore guns the patch of steel is larger relative to that of the small bore guns. Thus, the net wearing effect of 1000 rounds through a .22 caliber barrel is greater than a 1000 through a .308 caliber gun. For example, a 220 Swift will wear out a barrel faster than a 257 Roberts, given the same operating PSI and powders. Warrior says this best in my opinion.

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quote:

By boattailing the projectile the flow of boundry layer of the gas mass becomes turbulant and thus significantly more heat is transferred to the barrel steel increasing the potential for thermal erosion.

This is then obviously in contrast with those "tests" that were sited before, where the claim was made that a boatail bullet would actually extend barrel life. So, if the above is true, then it stands to reason that a boatail design with a slight angle and being short would be more desirable than those that features a long boatail designed to shift the CG more towards the middle in Spitzer bullets. Kind of solving one problem but creating another.

I always thought that a flat-based bullet seated to be flush with where the cases's shoulder and neck meets would be the most ideal from a combustion point of view, as well as to ensure a more stable position to engage the rifling square on, negating the possibility of the bullet to engage at an angle, unless the long-boatailed bullet is seated so it touches the rifling as Gerard suggests be done with his bullets.

Alf did your source refer to some experiments that were done or is it just a theoretical hypothesis? Also what about the propellant gas and unburnt particles that attempt to pass the bullet which gets wedged in the corners that the boatail form with the barrel - is there not an erosion effect?





Warrior

quote:

Originally posted by Wayfaring Stranger:
Soooo its high velocity that wears out barrles?

Tumbo speaks the truth!

No, it is high pressures, accompanied by high temperatures and high-velocity propellant gases. These work in combination to melt and carry away barrel steel, acting much like an acetylene torch. The bigger the powder charge relative to the bore diameter, the higher the pressure, the hotter the gases, and the faster the gases travel. This may or may not be accompanied by higher projectile velocity-but these effects are usually worse in rounds made with overly large capacities intended to produce extreme velocities.

SOME powders are/were much worse in this regard than others. One I remember was Cordite, which had a large nitroglycerine content. Even in the relatively small .303 British round, it ruined barrels PDQ!

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