How do people run their barrels? Clean or with copper?

[madyarra]

Just wondering how people run their barrels? Do you clean all the copper out or give it the odd clean now and again or when the copper affects accuracy?

 

Only wondering as I've not long got a lovely custom rifle which has just bedded in after 100 ish rounds and now has increased the pressure from my load. I'm assuming it's the copper that has lined the barrel increasing resistance/pressure.

[gbal]

Keep the barrel copper (and carbon etc) free-usually a good custom barrel cleans fairly easily with a good copper remover.

 

Out of some curiosity,how do you know /measure your 'increased pressure' ?

 

gbal

[The Gun Pimp]

An increase in pressure can occur after 100 - 200 rounds - but not in all barrels.

 

I wondered how this could be.

 

The only explanation I've heard is that as the minute 'imperfections' in the barrel's surface are smoothed out, the bullet makes greater contact - rather than riding on high-spots. This 'greater contact' creates more friction and thus more pressure.

 

Copper? Yes - with a match-grade barrel get it all out if you want to maintain accuracy.

[gbal]

Hmmm....one possibility,Vince-a bit more plausible than copper build up in 100 rounds restricting the bore-not a serious suggestion,otherwise many barrels without copper removal would show "the symptoms".....but since the lands engrave the bullet, it's going to be hard to attribute anything to very minor imperfections,though it would be more increased drag relate,then reduced as they wore away....and we might expect a bigger gain in unlapped/'rougher' factory barrels...

...but I was wondering more how any such pressure would be diagnosed,let alone measured. What might the symptoms be,that would be clearly only barrel related... Like progressive velocity increase...then plateauing when "smooth"...or better yet,optimal friction

Or any other explanation,for that matter....seems a tad 'Hypothetical'....

 

 

 

...it's a dull night on TV!

 

g

[madyarra]

This is the conclusion I have came up with. I decided on an accurate load that was a grain below any pressure signs on a hot day. I then loaded 75 ish rounds. Next day I went, same conditions and went to fire the first few rounds. All over pressure with heavy extractor marks.

 

I've read on quite a few forums and seen on vids that after between 50-100 shots of a new barrel the copper will line the bore essentially shrinking the diameter thus creating more pressure for the bullet to travel and exit the barrel.

 

It's a sassen stainless barrel for the record I have pulled some rounds and started loading from a lower charge. Dropped around 2gr back up to original charge. Thanks folks

[madyarra]

Velocity also increased by up to 70fps with same charge, primer, brass, conditions

[meles meles]

If you'll allow a mere metallurgist and tribologist to express an opinion...

 

When you fire a cartridge, you push a metal object down a metal tube with intimate contact between the two. As well as performing other functions, the copper jacket of the bullet provides a lubricative bearing surface between the bullet and the barrel, easing its passage and reducing wear. So far, so good.

 

Behind the bullet are supersonic gases at high high temperature ( >2500K) and pressure (circa 55,000 psi). These will scour and cut the steel at its weakest points, the grain boundaries. Very quickly, the interior barrel surface will look like crazy paving. However, the hot gases and the tribological effects of the copper jacked bullet squeezing down the barrel leave a thin layer of copper on the barrel surface, partially sealing these vulnerable grain boundaries and protecting them from the erosion / corrosion of each shot. Up to a certain point, the copper fouling actually helps preserve barrel life and promotes a more consistent shot to shot performance.

 

Cleaning out the copper both removes this copper plating and subjects the grain boundaries to further corrosive attack from the cleaning solvent. If it dissolves copper, think what it is doing to the elements and inclusions at the grain boundaries of the barrel steel.

 

We clean our rifles only if accuracy noticeably begins to decline., say after 500 shots or so. We then do a minimal clean: a carbon solvent, a nylon brush, then a dilute copper solvent to remove some but not all of the copper. More barrels are ruined by aggressive cleaning than by being 'shot out'.

 

 

That's just our two pen'orth, oomans. It's only based upon 11 years studying metallurgy at University and 20 years being a metallurgist, some of them in a ballistics lab. If it conflicts with your opinion, ignore us...

[madyarra]

Meles meles thanks for your thoughts, facts and opinions. I'm very open to hear any opinions and thoughts on this as apart from shooting tikkas this is my first custom barrel rifle. Just looking for guidance really. I am going to clean the rifle this time with copper solvent just to eliminate the possibility of this affecting my load but I do think after that I will be reverting back to the "if it ain't broke don't fix it routine".

[bradders]

I've read on quite a few forums and seen on vids that after between 50-100 shots of a new barrel the copper will line the bore essentially shrinking the diameter thus creating more pressure for the bullet to travel and exit the barrel.

 

Hearsay and general unfounded shooter speculation.

 

At that rate your .260 will become a .243, so no need to rebarrel, just change ammo to a different calibre

 

Pressure is generated in the firing of the cartridge, not 1/2 way down the bore, and it's funny no one has slugged a bore to find a diameter difference.....because fouling isn't accumulative and, for our purposes, immeasurable

I was at the Lapua/Nammo ammunition facility in Mesa, AZ watching them test fire .338 down test barrels in the 300M tunnel, testing ammunition for group on electronic targets and velocity through the chronos

 

We asked them how often they cleaned the barrels, and the answer was 1000rds

[bradders]

More barrels are ruined by aggressive cleaning than by being 'shot out'.

 

 

Another urban/firing point myth me thinks

[meles meles]

 

Another urban/firing point myth me thinks

 

 

Damn, we wasted so much money on our university education and developing CHARM III* then...

 

 

* CHARM III barrels hold the current long range tank to tank engagement record. First round strike against a moving target from a moving tank at 5,100m

[bradders]

 

 

Damn, we wasted so much money on our university education and developing CHARM III* then...

 

 

* CHARM III barrels hold the current long range tank to tank engagement record. First round strike against a moving target from a moving tank at 5,100m

120mm barrel vs a 6.5mm one?

I don't see the correlation between a 140gn bullet @ 2800fps vs one that weighs 20lbs a 4800fps, and MOT (Minute of Tank) isn't MOA, but we're talking pressure, not accuracy

 

I'm an empirical kind of guy, lead me to the proof

[meles meles]

The laws of physics scale.

 

A tank gun has to be more accurate than a soldier's rifle: the vulnerable points of a tank, measured in MOA, are smaller than those of a human.

 

However, as we said in our original post, if you prefer opinion over fact, ignore us. We badgers are small brained kreechers and easily dismissed.

[bradders]

The laws of physics scale.

 

A tank gun has to be more accurate than a soldier's rifle: the vulnerable points of a tank, measured in MOA, are smaller than those of a human.

 

However, as we said in our original post, if you prefer opinion over fact, ignore us. We badgers are small brained kreechers and easily dismissed.

I generally tried to, the Badger and ooman bo**ocks is somewhat tedious,

Bon Voyage

[meles meles]

*slinks away, thoroughly dismissed...*

[jcampbellsmith]

In answer to the original question. I use a foam cleaner and then a copper cleaner until the patches emerge clean. I then clean the chamber. If required I may clean the bolt log recess. I will then run a final dry patch through the bore.

I used to clean the barrel after every outing that's had a shot fired. I clean less frequently now, but will generally clean before and after every competition or load development session.

My rifles are all primarily for stalking, but they do shoot well in competitions too.

Regards

JCS

[madyarra]

I should maybe add that this is a stalking and plinking or more like whacking rifle. Not a match or competition rifle

[bradders]

I should maybe add that this is a stalking and plinking or more like whacking rifle. Not a match or competition rifle

 

Well I wouldn't worry too much about pressure, but given the frequency of use and the conditions, I'd at least run a few solvent soaked patches through it, and maybe back the charge down a bit

[Breacher]

It never ceases to amaze me that after years of debate this question has still to be answered once and for all with actual proof.

 

For what its worth...... I clean my rifle after EVERY use. If it is just one round or a few rounds after a stalk, one patch of wipe out, pause for a few minutes then a couple of dry patches. If its after a competition and I have fired more rounds, I do the same but add more patches of wipeout and a couple of passes with a bronze brush.

 

I never use a boresnake. And I remove the suppressor, clean the crown and leave the suppressor off until going out again. I have heard of crown corrosion issues with dirty suppressors being left in place.

[Chanonry]

It never ceases to amaze me that after years of debate this question has still to be answered once and for all with actual proof.

 

 

Life would be toooo long.

 

but feel free

[Grum87]

Run a barrel til it accuracy tails off.

 

I've a Pacnor supermatch with over 1600 rounds through it, usually cleaned at 200-300 round intervals because I start to feel guilty about it, more than through a need to clean it.

 

To this day I've never had any copper out of it.

[DaveM]

If you'll allow a mere metallurgist and tribologist to express an opinion...

 

When you fire a cartridge, you push a metal object down a metal tube with intimate contact between the two. As well as performing other functions, the copper jacket of the bullet provides a lubricative bearing surface between the bullet and the barrel, easing its passage and reducing wear. So far, so good.

 

Behind the bullet are supersonic gases at high high temperature ( >2500K) and pressure (circa 55,000 psi). These will scour and cut the steel at its weakest points, the grain boundaries. Very quickly, the interior barrel surface will look like crazy paving. However, the hot gases and the tribological effects of the copper jacked bullet squeezing down the barrel leave a thin layer of copper on the barrel surface, partially sealing these vulnerable grain boundaries and protecting them from the erosion / corrosion of each shot. Up to a certain point, the copper fouling actually helps preserve barrel life and promotes a more consistent shot to shot performance.

 

Cleaning out the copper both removes this copper plating and subjects the grain boundaries to further corrosive attack from the cleaning solvent. If it dissolves copper, think what it is doing to the elements and inclusions at the grain boundaries of the barrel steel.

 

We clean our rifles only if accuracy noticeably begins to decline., say after 500 shots or so. We then do a minimal clean: a carbon solvent, a nylon brush, then a dilute copper solvent to remove some but not all of the copper. More barrels are ruined by aggressive cleaning than by being 'shot out'.

 

 

That's just our two pen'orth, oomans. It's only based upon 11 years studying metallurgy at University and 20 years being a metallurgist, some of them in a ballistics lab. If it conflicts with your opinion, ignore us...

My regime as well. Used to clean religiously but no longer. I anything I remove carbon and leave until there is a decline in accuracy.

Guess we do what feels right and there are always going to be differing points of view.

[furrybean]

Run a barrel til it accuracy tails off.

 

I've a Pacnor supermatch with over 1600 rounds through it, usually cleaned at 200-300 round intervals because I start to feel guilty about it, more than through a need to clean it.

 

To this day I've never had any copper out of it.

 

But when will accuracy drop off?

For me that could be half way through a detail. I clean about every 100 rounds or so

[TJC]

Listen to a George. He knows more than he rest of us combined. Simple.

 

[gbal]

furrybean raises an important point.Different shooters,from the serious competitor,to the hunter/varminter,tothe casual plinker,have different concerns,including cleaning/not and it's impact on their shooting.Implicitly too,different but quite legitimate, ideas as to what is 'accurate'. Depending too,on the size of the target,they might differ in just when they notice any decline in 'accuracy'-perhaps better here described as 'precision'-the intrinsic ability of the rig to put bullets close together (this includes ammo,of course-but we are concerned with barrel cleaning regimes).

 

For some (eg short range Bench Rest ) a group increase of .1moa would be serious-rifle is no longer competitive;hunters might not even notice that in the field,as it has very little effect on sucess,and plinkers likewise....

...I have a 243 that has had many thousands of shots through it-no need for a borescope,barrel is serious crazy paving for itsentire length....but still brings down F11s as far as it ever did,but it's 'hit postage stamp 5/5 at 200y" is long gone...not sure it would hit the postcard most shots...

 

One related observation,is that the more competitive ,precision/accuracy oriented disciplines seem to more rigourous about cleaning/copper/carbon removal-which suggests it matters for best performance.Some field shooters don't seem to have used copper remover ever....but can still hit fields....:-).

 

Is barrel cleanliness next to godliness?...well,I'm an atheist. Go figure,for your needs

 

gbal