Damaged Crown due to Brass Jag?

[ThePlinkster]

Hey guys

I stumbled accross this video:
(A common mistake can damage your .22LR)
https://m.youtube.com/watch?v=OC5v3csxuUM

And in this video

This guy claims that a "brass jag" can damage the crown of a rifle as the jag travels in and out of the muzzle of the rifle
He claims that the brass jag can (little by little) chip away the crown of the rifle thus deteriorating the accuracy of the rifle in the long run

Do you guys reckon that this is true?

Can a brass jag damage the crown of a rifle?
(As it travels in & out of the muzzle of the rifle)

I've looked into it briefly
And I'm not sure myself
However
I do know that brass is weaker than steel
(Steel being the material that most rifle barrels are made of)
So, the barrels of our rifles are stronger than our brass jags, that's for sure

But what do you guys reckon?

Do you guys pay particular attention when your brass jags travel in and out of the muzzle of your rifles during the cleaning process?

[SCJ429]

Yes you can damage your crown with a brass Jag. Given time you can wear away steel with any number of softer metal. Pays to be careful when you pull the jag back through the muzzle after you retrieve your patch.

[Oldbloke]

Brass is softer than steel. Steel resists abrasion better than brass. The brass may wear but not the steel.

So, "No way hos'e".

Having said that any dirt that is harder than steel that is on the brass jag could theoretically afraid the crown. But would take many years.

P.S. stop cleaning your 22lr

[bladeracer]

Brass is softer than steel. Steel resists abrasion better than brass. The brass may wear but not the steel.

So, "No way hos'e".

Having said that any dirt that is harder than steel that is on the brass jag could theoretically afraid the crown. But would take many years.

P.S. stop cleaning your 22lr

When two materials run together, both surfaces wear, the "harder" surface just wears more. Even a piece of cloth with eventually wear metal away.

[bladeracer]

Normal practice is to remove the jag before drawing the rod back through the bore, but I don't consider in necessary. Personally, I prefer to use a nylon brush as the jag with a patch wrapped around it, I feel it keeps the patch in firmer contact over a greater area, and the nylon bristles do less damage than metal.

I would strongly suggest not cleaning. 22LR bores until accuracy starts to degrade. The bore becomes coated with wax lube, you should never get any leading with properly lubricated bullets in .22LR.

[No1Mk3]

I have never damaged a crown through use of a jag, Mohs Scale determines that wear will not occur in your lifetime unless you clean daily and live a very long time. What can damage the crown is use of a wood, fibreglass or nylon rod from the muzzle end with Silica particles embedded in the rod abrading the crown. This kind of damage is often seen in military rifles subjected to cleaning with a pull through where the string is allowed to ride on the edge, and although many will tell you it is the string that causes the damage it is in fact the hard grit embedded in the string. I would say that the high velocity projectile (often steel jacketed) and very hot gases from firing will damage your crown long before any cleaning damage shows up, Cheers.

[No1_49er]

(1) What can damage the crown is use of a wood, fibreglass or nylon rod from the muzzle end with Silica particles embedded in the rod abrading the crown.
(2) This kind of damage is often seen in military rifles subjected to cleaning with a pull through where the string is allowed to ride on the edge, and although many will tell you it is the string that causes the damage it is in fact the hard grit embedded in the string.

(1) Which is why muzzle loader firearms that are used for precision / target shooting will have a muzzle-guide on the cleaning and loading rods.
(2) Just like its modern iteration, the "bore snake" which functions in exactly the same way.

[Oldbloke]

Brass is softer than steel. Steel resists abrasion better than brass. The brass may wear but not the steel.

So, "No way hos'e".

Having said that any dirt that is harder than steel that is on the brass jag could theoretically afraid the crown. But would take many years.

P.S. stop cleaning your 22lr

When two materials run together, both surfaces wear, the "harder" surface just wears more. Even a piece of cloth with eventually wear metal away.

Nonsense.
Car bigends, one is cast iron the other white metal. (Lead and tin) How fast do they wear out?

Bronze bushes in old electric motors, almost no lube. Running for years.

Steel hammer hitting copper or brass punch to knock in bearings the punch mushrooms, but hammer lasts a lifetime.

And we are worried about a brass jag, would take 100s of 000s of strokes.

Utterly laughable.

[Oldbloke]

I have never damaged a crown through use of a jag, Mohs Scale determines that wear will not occur in your lifetime unless you clean daily and live a very long time. What can damage the crown is use of a wood, fibreglass or nylon rod from the muzzle end with Silica particles embedded in the rod abrading the crown. This kind of damage is often seen in military rifles subjected to cleaning with a pull through where the string is allowed to ride on the edge, and although many will tell you it is the string that causes the damage it is in fact the hard grit embedded in the string. I would say that the high velocity projectile (often steel jacketed) and very hot gases from firing will damage your crown long before any cleaning damage shows up, Cheers.

100% correct.

[straightshooter]

Dear Plinkster
Of course it is true!
Just as it is equally true that every time you exhale you are contributing CO2 to, and thus are the cause of, the forthcoming climate disaster, should you be a worshipper of that particular religion.
Now think about what you see in the video and not what the spruiker is telling you.
He is cleaning from the breech, he is using an uncoated steel cleaning rod and the end of the rod with jag appear to be reasonably well centered in the muzzle. That means the rod is being supported within the barrel in some way that is not made apparent.
What should be happening is the weight of the cleaning rod should cause it to sag and you should have steel rubbing on steel which will cause far more damage than brass on steel both at the muzzle and elsewhere.

[SCJ429]

Nonsense.
Car bigends, one is cast iron the other white metal. (Lead and tin) How fast do they wear out?

Utterly laughable.

Have you ever seen a crank that has spun a bearing? What caused the grooves that were carved into the big end? The bearing ran out of oil and friction wore away at the steel.

You can also punch holes in steel with soft copper and lead bullet. Why can soft metals travelling at 3,000 fps damage a much harder metal?

Barrel makers always complain that they see damage to their barrels caused by poor cleaning practices.

[JimTom]

I guess it’s possible if you’re a bit hand fisted, for want of a better term. I always remove the jag prior to pulling the rod back through the barrel.

[Gamerancher]

Soft material will wear through steel.
I've seen rubber brake hoses wear through truck diff housings to the point where they leaked oil. ( Talking 1/2" thick Mack diff housings here )
Nylon air lines rub through high pressure steel fuel injector lines to the point where they leak.
Countless other examples of "soft" material wearing through steel on chassis, axles, etc.
As pointed out above, it is a total bugbear to barrel makers, the damage that is done to barrels through bad cleaning practices, ( crown damage is high on the list ), that leads to lower performance or lifespan, which is then blamed on the quality of the barrel.

[bladeracer]

If your conrod bearings are touching your crankshaft you have a serious issue. They should never touch, the rod floats on a film of oil.

Hammers are hardened.

I didn't say it would happen quickly, or that brass jags are a problem as we use them. But if the brass touches the steel, both will wear to some degree.

Brass is softer than steel. Steel resists abrasion better than brass. The brass may wear but not the steel.

So, "No way hos'e".

Having said that any dirt that is harder than steel that is on the brass jag could theoretically afraid the crown. But would take many years.

P.S. stop cleaning your 22lr

When two materials run together, both surfaces wear, the "harder" surface just wears more. Even a piece of cloth with eventually wear metal away.

Nonsense.
Car bigends, one is cast iron the other white metal. (Lead and tin) How fast do they wear out?

Bronze bushes in old electric motors, almost no lube. Running for years.

Steel hammer hitting copper or brass punch to knock in bearings the punch mushrooms, but hammer lasts a lifetime.

And we are worried about a brass jag, would take 100s of 000s of strokes.

Utterly laughable.

[bladeracer]

Friction occurred because the oil film broke down allowing the bearing to touch the crankshaft.

Nonsense.
Car bigends, one is cast iron the other white metal. (Lead and tin) How fast do they wear out?

Utterly laughable.

Have you ever seen a crank that has spun a bearing? What caused the grooves that were carved into the big end? The bearing ran out of oil and friction wore away at the steel.

You can also punch holes in steel with soft copper and lead bullet. Why can soft metals travelling at 3,000 fps damage a much harder metal?

Barrel makers always complain that they see damage to their barrels caused by poor cleaning practices.

[straightshooter]

Gamerancher
I don't believe you are a practising journalist so you should limit the hyperbole and tell the whole story not just the bits that tend towards a misleading understanding or a belief in magic.
Only an idiot (and unfortunately there are quite a few of them around) would believe that it's the actual rubber brake hose and not the abrasive materials that find their way in between the rubber and your 1/2" thick diff housing that do the damage.
Similarly for your nylon air lines.
For those still confused but interested read up on how and why a lap works.

[bladeracer]

Gamerancher
I don't believe you are a practising journalist so you should limit the hyperbole and tell the whole story not just the bits that tend towards a misleading understanding or a belief in magic.
Only an idiot (and unfortunately there are quite a few of them around) would believe that it's the actual rubber brake hose and not the abrasive materials that find their way in between the rubber and your 1/2" thick diff housing that do the damage.
Similarly for your nylon air lines.
For those still confused but interested read up on how and why a lap works.

Back in the days when we were just getting into steel-braided brake lines on the racebikes, they weren't rubber-coated. You had to be very careful routing them away from everything as they were essentially chainsaws and would eat through anything as your suspension moved up and down.

But even pure water will wear away very hard surfaces over time.

[Gamerancher]

Straightshooter, I was replying to Oldbloke saying "No way Jose" that softer material will cause wear in steel.
I don't believe it is some sort of "magic" either, it is mostly caused the action of smaller abrasive particles acting on the steel.
BUT, it won't happen without the softer material acting in conjunction.
Perhaps you are the journalist taking things out of context???

[Bugman]

Settle down people. Now on a lighter side, my Sako 17HMR instruction say that cleaning it should not be done with a brush, just a patch and the appropriate cleaning agent. Could it be that a brush could easily damage the barrel etc? Food for thought.

[Wm.Traynor]

I guess it’s possible if you’re a bit hand fisted, for want of a better term. I always remove the jag prior to pulling the rod back through the barrel.

Me too. It's easy and the jag is never screwed tightly on to the rod either.

[Oldbloke]

We are not talking 4,000 rpm.
Its a few strokes a week,, if that.
The jag isn't traveling at 3,000 fps. More like 1 fps.

Read this
https://en.m.wikipedia.org/wiki/Mohs_sc ... l_hardness


Its the dirt, not the brass.

[JohnV]

If you go gently while cleaning no damage will happen . Make sure the jag fits nice and flush on the outer edge of the rod thread .
Only push the jag out enough to drop or remove the patch . Pull back gently .

[LawrenceA]

Chip the steel no way. Barrels are tough and not brittle.
Brass wear steel No way. Brass is too soft.
BUT Grit can imbed in the brass which can abrade steel over time. This is what damages crowns.
This is why laps are made from soft metal and why most top end rods are stainless steel.
If grit imbeds then it imbeds in the barrel and wears the rod.

Anyway that is my 2 cents

[JohnV]

Chip the steel no way. Barrels are tough and not brittle.
Brass wear steel No way. Brass is too soft.
BUT Grit can imbed in the brass which can abrade steel over time. This is what damages crowns.
This is why laps are made from soft metal and why most top end rods are stainless steel.
If grit imbeds then it imbeds in the barrel and wears the rod.

Anyway that is my 2 cents

I agree it's the potential grit that can cause an issue over time . How you clean has a lot to do with it also . Did you know that some primers contain powdered glass . That's the hot sparks you see coming from some ignited primers magnums being the worst and Federal 210 Match being about the mildest .

[Oldbloke]

I agree it's the potential grit that can cause an issue over time . How you clean has a lot to do with it also . Did you know that some primers contain powdered glass . That's the hot sparks you see coming from some ignited primers magnums being the worst and Federal 210 Match being about the mildest .

That's a very good point. Glass is a great abrasive and certainly has potential to eventually do damage. Think cabinet makers glass paper.

The ground glass is added in order to increase the impact sensitivity of the primer compound.

[LawrenceA]

I agree it's the potential grit that can cause an issue over time . How you clean has a lot to do with it also . Did you know that some primers contain powdered glass . That's the hot sparks you see coming from some ignited primers magnums being the worst and Federal 210 Match being about the mildest .

That's a very good point. Glass is a great abrasive and certainly has potential to eventually do damage. Think cabinet makers glass paper.

The ground glass is added in order to increase the impact sensitivity of the primer compound.

WOW!!
Did not know any of that.
Thank you

[Oldbloke]

Keep in mind there isn't a lot and most of it would be instantly melted into glass beads and ejected out of the muzzle. And since its a glass bead there are no sharp edges to abraid.

But there is certainly potential there. How much is anybodies guess. Its been used for many years. Embed it into a jag or brush it could easily be a problem if there us enough. As far as the carbon in the barrel, I think its fairly low risk. But you would need to test its ability to abraid I guess. (Hardness on the moh scale)

[Die Judicii]

Nonsense.
Car bigends, one is cast iron the other white metal. (Lead and tin) How fast do they wear out?

Bronze bushes in old electric motors, almost no lube. Running for years.

Steel hammer hitting copper or brass punch to knock in bearings the punch mushrooms, but hammer lasts a lifetime.

And we are worried about a brass jag, would take 100s of 000s of strokes.

Utterly laughable.

OB,

Big end bearings in cars are lubricated with the oil which theoretically should have no grit contained in it due to filtration.

The bronze bushes you speak of would normally be "sintered bronze" which has lubricant in itself.

And,,,, there is a big difference between "impact" and "abrasion".

Somebody (above) mentioned rubber and nylon brake lines wearing through a cast steel diff housing.
This will readily occur especially so if there is an abrasive agent combined. eg. sand/mud/water/grease/oil plus friction/vibration/rubbing = soft wearing away or abraiding the harder material.

[on_one_wheel]

Imagine the wear a piece of interference fitted copper slammed through the barrel accelerating from 0 at the lands to 3000 fps at the crown followed by a blast of extreme heat must do, especially when with each subsequent shot the barrel gets another coating of burnt and in some cases unburned powder, carbon and whatever crud spits out of the primer. Then think about the super heated gas that explodes out through the crown behind the projectile with its burning powder, carbon, copper and crud all mixed with the gas like a super pressurised, super heated high velocity abrasive s**t storm.
Its incredible how long barrels last when you consider the sort of abuse they are subjected to.

A brass jag is the last of my concerns when it comes to my barrels life or crown damage.
I'm not afraid to scrub my barrel with a bronze brush and pull a bare jag back through after pushing through patches.

[Oldbloke]

Nonsense.
Car bigends, one is cast iron the other white metal. (Lead and tin) How fast do they wear out?

Bronze bushes in old electric motors, almost no lube. Running for years.

Steel hammer hitting copper or brass punch to knock in bearings the punch mushrooms, but hammer lasts a lifetime.

And we are worried about a brass jag, would take 100s of 000s of strokes.

Utterly laughable.

OB,

Big end bearings in cars are lubricated with the oil which theoretically should have no grit contained in it due to filtration.
You are of course correct, but think of the incredible pressure involved and the 3000 rpm for 1000s of hours. And a jag, at 10 or so stokes pm

The bronze bushes you speak of would normally be "sintered bronze" which has lubricant in itself.

And,,,, there is a big difference between "impact" and "abrasion".

It is different, but my point was the differences in the forces involved.

Somebody (above) mentioned rubber and nylon brake lines wearing through a cast steel diff housing.
This will readily occur especially so if there is an abrasive agent combined. eg. sand/mud/water/grease/oil plus friction/vibration/rubbing = soft wearing away or abraiding the harder material.

brass is much softer than barrel steel, so if there is no "dirt/abrasive, then the steel will not get worn/abraded However add say some alluminium oxide or carborundum (both very hard on the MOH scale) you will definitely get barrel wear

In summery IMO, if the brass jag is clean you will not wear the barrel crown. But if dirt is added, depending on the dirts hardness and shape (yes shape matters) you will s l o w l y wear the crown.