Chamber dimensions to allow not cleaning

Ryan Avery

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Shoot2HuntU
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Not poking at you or anyone here but we get this a lot... and we will say this...

Would you drive your car and never change the oil and filter?

I will also say the following in no random order....

Type of powder and cartridge/case capacity is a huge variable. The bigger the case capacity and or the smaller the bore size fouling goes up. You will have to clean it more often.

Some cartridges like 308win vs bore size are vary forgiving. A 300wm or a 300 Norma won't be forgiving. Same for a 6BR vs a 243win or a 6CM. By increasing the case capacity you have turned 243w and 6CM into magnum rounds.

Type of powder and quality of powder. I do think there is a powder quality problem and or availability issues. This in turn is causing a fouling pressure problems which in turn causes accuracy and pressure issues to the point of piercing primers etc... I/we've been seeing issues with box ammo and the powder being used to load the box ammo... and it causing fouling/pressure issues. I just seen it this past November and go figure it was with a 308w gun.

You make the throat freebore diameter bigger and you effect barrel life as well as you will effect accuracy issues. Bigger doesn't mean better... tighter doesn't mean better either. If I had to pick a number I'd say .001" to .0015" on the freebore diameter vs the bullet diameter for clearance. That's as big as I would want to go and still maintain a high accuracy level. You might get away with a +.002" diameter on the throat vs bullet diameter but after that you get what you get. Loaded ammo/bullet runout will also come into play here as well.

Also not talked about is bullet quality or should I say consistency in bullet diameter/sizes.

I hate cleaning as much as the next guy but I will say this... I shoot it... I clean it. Don't clean and you will have issues somewhere down the line. Your just asking for it.

Later, Frank
Bartlein Barrels

Frank thanks for posting this. I have a few questions.

How many barrels have you personally shot out and not cleaned? Correct me if I’m wrong but haven’t you stated you can blow up a barrel by not cleaning it?

I have shot out quite a few 300 Rum barrels all went between 800 to 900 rounds with zero cleaning. I shot out a 6UM at 730 rounds zero cleaning it was shooting right up till it wasn’t with a tiny bit of land chasing.

This may sound like an attack but truthfully I’ve heard so many different cleaning procedures for each barrel manufacturer it’s hard to believe there really is a right answer.


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But lots of us don't clean and don’t have issues. So what is your explanation there? Are we all just somehow lucky?
Yep lucky.

There are just too many variables but I will stand and say... don't clean it and problems are bound to happen some where.

Also think of this... once you have an issue and it doesn't matter if it's an accuracy issue (carbon fouling can cause accuracy issues as well and not just copper fouling) but once you have an issue... a 15 minute or 30 minute cleaning session isn't going to fix it. Doing a quick clean on it you might see the accuracy come back or the pressure issue go away but don't be surprised if it only last for like 15 rounds fired.

You will be cleaning it for a while!
 
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Frank thanks for posting this. I have a few questions.

How many barrels have you personally shot out and not cleaned? Correct me if I’m wrong but haven’t you stated you can blow up a barrel by not cleaning it?

I have shot out quite a few 300 Rum barrels all went between 800 to 900 rounds with zero cleaning. I shot out a 6UM at 730 rounds zero cleaning it was shooting right up till it wasn’t with a tiny bit of land chasing.

This may sound like an attack but truthfully I’ve heard so many different cleaning procedures for each barrel manufacturer it’s hard to believe there really is a right answer.


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I've shot out barrels but sorry.... I've done routine/cleaning maintenance on them.

Also and I'll say this again... put it away dirty.... even s.s. barrels and that can cause pitting/etching to the bore.

Didn't take it as an attack.... so no worries.

This is a very difficult thing to diagnose at times... how come one guy can have one or several guns and not clean them and not have a accuracy issue and or pitting issues, or pressure issues etc...? but... then the next guy does!

This is also a reason why the ammo makers have set cleaning cycles. It can be caliber dependent. I know one place with 308w if they are pressed for time will go up to 150 rounds in between cleanings but most of the time they clean after every 50 rounds fired. This is accuracy testing not pressure testing. Most pressure test barrels they clean after every 50 rounds fired. Very rarely do they push it 100 rounds. Why? They are loading for a spec pressure and velocity. The build up of fouling will have in impact on pressures and velocities. YOU.... the individual might not see a pressure issue like hard bolt lift etc... but they will see it on the pressure readings.

I know one place loading 300 Norma... to hold spec accuracy and pressure requirements.... they are only getting 500-600 rounds out of the pressure and velocity test barrels.

Also I can't name the cartridge.... but one place learned from early testing.... they can wreck the barrel in 150 rounds with no cleaning. To get the barrels to last and hold even an accuracy requirement of 1moa.... they have to clean that caliber every 20-30 rounds fired! Then they can get about 450 to maybe 750 rounds out of the barrel but most quite shooting at 450-500 rounds.

Later, Frank
 
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atmat

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Yep lucky.

I've shot out barrels but sorry.... I've done routine/cleaning maintenance on them.

So how can you call it luck if you’ve never tried it? Have you personally witnessed someone try shooting a barrel out without cleaning to see the results?

My issue here is that everyone says cleaning is conventional wisdom, but few seem willing to test that theory or even gain the experience to the contrary

I would think you would have a vested interest in trying. Then you could advertise that your barrels are no-clean and have a leg up on your competition.
 

BBob

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Then you could advertise that your barrels are no-clean and have a leg up on your competition.
Yup, then that guy who has not cleaned it says it won't shoot and sends it to Frank for eval who now has to clean it to be able to evaluate it. That's not going to happen. :)
 
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So how can you call it luck if you’ve never tried it? Have you personally witnessed someone try shooting a barrel out without cleaning to see the results?
I've got too much data from ammunition test barrels that we make for ammo and bullet makers to see what happens if you don't clean them.

See my post #64.

This is an extreme example/cartridge but it is an example.....

"Also I can't name the cartridge.... but one place learned from early testing.... they can wreck the barrel in 150 rounds with no cleaning. To get the barrels to last and hold even an accuracy requirement of 1moa.... they have to clean that caliber every 20-30 rounds fired! Then they can get about 450 to maybe 750 rounds out of the barrel but most quite shooting at 450-500 rounds."
 
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Also some cartridges like 26 Nosler for example.... can build fouling up so fast that some ammo/bullet makers couldn't get enough consistent data to put it in they're loading manuals.
 
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Yup then that guy who has not cleaned it says it won't shoot and sends it to Frank for eval who now has to clean it to be able to evaluate it. That's not going to happen. :)
Yep been down that road and still go down that road.

Good example and I'll use it again. I had two guys call me with in a month of each other. 6.5PRC was the caliber for both. The one guy also sends me pictures of the throat and says... look at all the fire cracking. The barrel quite shooting and died early. I said no it's not dead! That's carbon fouling!!!!!!!!!!! He listened to me and I told him how to clean it to get the barrel back to shooting. Barrel had exactly 288 rounds on it and never cleaned it from the first round fired.

So he cleans the barrel like I told him and he shot it in a PRS match that next weekend. Called me early the next week and says... I won the 1200 and 1400 yard portions of the match. Gun shot great and held accuracy the whole time.... I need to clean the barrel where his exact words. Lesson learned.
 
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Article 4

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I've got too much data from ammunition test barrels that we make ammo and bullet makers to see what happens if you don't clean them.

See my post #64.

This is an extreme example/cartridge but it is an example.....

"Also I can't name the cartridge.... but one place learned from early testing.... they can wreck the barrel in 150 rounds with no cleaning. To get the barrels to last and hold even an accuracy requirement of 1moa.... they have to clean that caliber every 20-30 rounds fired! Then they can get about 450 to maybe 750 rounds out of the barrel but most quite shooting at 450-500 rounds."
I am aligned with you Frank - I am/was personally present when a large bbl manufacturer (most of us here run them at some point) I was working with tested with SOCOM for a contracted activity. Using predetermined MIL-STD-810 and other requirements for accuracy, POI Shift, and environmental variances as it affects rifle bbl life and overall rifle performance. These were bolt gun tests. Cliff notes on the results from 2015:
  • BBL fouling increased variances with accuracy and POI shift as round counts increased - chronograph SD's and ES's were measured as well
  • Fouled bbls/chambers/throats were more susceptible to environmental inputs and specifically temperature/humidity extremes - affected feeding and chamber pressures as round counts increased
  • Fouled and dirty chambers/throats mixed with adverse conditions (sand, mud, rain, dirt etc...) increase feed issues, bolt issues, and chamber pressures.

Like your analogy of engine oil.
Look, if you are getting what you want from your dirty bbl, fine. Again I will say, if properly cleaning and bbl does no harm and is likely going to help the life and accuracy of your bbl, why would not NOT do it.
 
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I am aligned with you Frank - I am/was personally present when a large bbl manufacturer (most of us here run them at some point) I was working with tested with SOCOM for a contracted activity. Using predetermined MIL-STD-810 and other requirements for accuracy, POI Shift, and environmental variances as it affects rifle bbl life and overall rifle performance. These were bolt gun tests. Cliff notes on the results from 2015:
  • BBL fouling increased variances with accuracy and POI shift as round counts increased - chronograph SD's and ES's were measured as well
  • Fouled bbls/chambers/throats were more susceptible to environmental inputs and specifically temperature/humidity extremes - affected feeding and chamber pressures as round counts increased
  • Fouled and dirty chambers/throats mixed with adverse conditions (sand, mud, rain, dirt etc...) increase feed issues, bolt issues, and chamber pressures.

Like your analogy of engine oil.
Look, if you are getting what you want from your dirty bbl, fine. Again I will say, if properly cleaning and bbl does no harm and is likely going to help the life and accuracy of your bbl, why would not NOT do it.
We're on the same page bud!
 
OP
H
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Again I will say, if properly cleaning and bbl does no harm and is likely going to help the life and accuracy of your bbl, why would not NOT do it.

Why? My motivation is to spend less money and time cleaning, spend less rounds "fouling", not worry zero/poi shift from cleaning, be able to use the rokstock without having to take the action out of the stock or clean from muzzle end, etc.

I do not have hopes to be a 1/2moa on demand shooter. 1-1.5 moa is fine for my application. If that can be achieved without cleaning a barrel, I'd rather not spend my time and money doing it.

It apparently workw for some, so I'd like to figure out what helps to allow it.

But I must say that it is not analogous to changing engine oil, because it is not an engine.
 

Article 4

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Why? My motivation is to spend less money and time cleaning, spend less rounds "fouling", not worry zero/poi shift from cleaning, be able to use the rokstock without having to take the action out of the stock or clean from muzzle end, etc.

I do not have hopes to be a 1/2moa on demand shooter. 1-1.5 moa is fine for my application. If that can be achieved without cleaning a barrel, I'd rather not spend my time and money doing it.

It apparently workw for some, so I'd like to figure out what helps to allow it.

But I must say that it is not analogous to changing engine oil, because it is not an engine.
Wait, a rifle bbl is not an engine? Whew, thanks for clearing that up.

What allows/helps not cleaning? Not cleaning.
If the idea is to never clean; don't. Problem solved.

Enjoy!!!
 
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OP
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Wait, a rifle bbl is not an engine? Whew, thanks for clearing that up.

What allows/helps not cleaning? Not cleaning.
If the idea is to never clean; don't. Problem solved.

Enjoy!!!

My intent is not to be argumentative or snarky. You asked why, and that is my answer. Of course one can go ahead and proceed without cleaning for the life of the barrel if they want to. I'd like to figure out what about the chamber dimensions allows that without having to change the load after it's established due to pressure problems, or without having other catastrophic problems.

Why use an engine oil analogy if they are not similar items?
 

idahodave

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My opinion/experience be damned....but this thread is ground zero on why folks should take EVERYTHING they read on the internet with a grain of salt.

The harder a person defends their "stance" on any given topic, the more dubious I become.

YMMV.

Dave
 

Afhunter1

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I started not cleaning out of laziness and now I’m cool! Ha ha. I haven’t touched the bore of my 17rem in 4 or 5 years. Probably up to 250-300rnds since last cleaning. I got one of those cool Garmin chrono’s the other day so I got it out to play with it. I shot my first shot and moved it 1 click left then shot my second shot and moved it 1 click left then shot my third shot and moved it one click up and shot final shot. 25gr Berger target @ 4K

CZ 527 m1 with shilen select match barrel

IMG_5971.png

I should mention that the reason it didn’t retain zero from last time out is……you know. Can’t wait to change them all out. I need one of those new mavens 1.2’s.

3931a0da28106ac5bac988c0226e8be2.jpg
 
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atmat

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I started not cleaning out of laziness and now I’m cool! Ha ha. I haven’t touched the bore of my 17rem in 4 or 5 years. Probably up to 250-300rnds since last cleaning. I got one of those cool Garmin chrono’s the other day so I got it out to play with it. I shot my first shot and moved it 1 click left then shot my second shot and moved it 1 click left then shot my third shot and moved it one click up and shot final shot. 25gr Berger target @ 4K

CZ 527 m1 with shilen select match barrel

View attachment 669080

I should mention that the reason it didn’t retain zero from last time out is……you know. Can’t wait to change them all out. I need one of those new mavens 1.2’s.

3931a0da28106ac5bac988c0226e8be2.jpg
It’s crazy how so many of us are lucky to have barrels that don’t need cleaned.
 
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Why? My motivation is to spend less money and time cleaning, spend less rounds "fouling", not worry zero/poi shift from cleaning, be able to use the rokstock without having to take the action out of the stock or clean from muzzle end, etc.

I do not have hopes to be a 1/2moa on demand shooter. 1-1.5 moa is fine for my application. If that can be achieved without cleaning a barrel, I'd rather not spend my time and money doing it.

It apparently workw for some, so I'd like to figure out what helps to allow it.

But I must say that it is not analogous to changing engine oil, because it is not an engine.
The engine oil comparison is this.... do zero maintenance... expect problems.

The number one thing we see when a customer has a problem is from no cleaning and improper cleaning.

Had a guy send in a 223 bolt gun about a year ago. Shot 750ish rounds thru it with out cleaning. Put it away dirty for like 6-9 months. Finally went to clean it... he took the suppressor brake off of it and while cleaning it and started getting all the carbon off the face of the muzzle... it was all pitted/corroded. He got lucky... no pitting in the bore and the crown wasn't damaged. Again why does it happen to one guy and not another or in one spot vs another spot.

Same thing with the bore... can't tell you how many used rifles I bought or looked at and the bore was pitted/corroded and it was from not doing any cleaning.

If your not worried about velocity changes, and your good with a 1.5moa accuracy good to go. If you see problems and or not meeting your goals/spec then you will have to do something to fix it.
 

atmat

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The engine oil comparison is this.... do zero maintenance... expect problems.

The number one thing we see when a customer has a problem is from no cleaning and improper cleaning.

Had a guy send in a 223 bolt gun about a year ago. Shot 750ish rounds thru it with out cleaning. Put it away dirty for like 6-9 months. Finally went to clean it... he took the suppressor brake off of it and while cleaning it and started getting all the carbon off the face of the muzzle... it was all pitted/corroded. He got lucky... no pitting in the bore and the crown wasn't damaged. Again why does it happen to one guy and not another or in one spot vs another spot.

Same thing with the bore... can't tell you how many used rifles I bought or looked at and the bore was pitted/corroded and it was from not doing any cleaning.

If your not worried about velocity changes, and your good with a 1.5moa accuracy good to go. If you see problems and or not meeting your goals/spec then you will have to do something to fix it.
Do you have any data on cleanliness vs precision you can share? How dirty before precision starts to slip? What are your recommendations for frequency of cleaning?
 
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Do you have any data on cleanliness vs precision you can share? How dirty before precision starts to slip? What are your recommendations for frequency of cleaning?
Pick a caliber.

How many rounds are on the barrel? That's a variable. A new barrel vs a barrel with a high round count on it will be different.

How the barrel was made is a variable and what the bore and groove sizes are and chamber spec are a variable.

A magnum type caliber will tend to be worse vs a non magnum caliber. So a 308win vs a 300wm or a 6.5CM vs a 6.5PRC etc...

So lot's of variables!

Type of powder being used? That's another one.

I know of two test that were just done last November and last month. I won't name the ammo makers... one caliber was 6.5CM and no the ammo maker was NOT... Hornady! Ammo barely shot under 1moa. Powder created a lot of fouling... Almost a hundred rounds of ammo where pulled... all the powder dumped and reloaded with the old standby of H4350.... ammo went to shooting sub .5moa.

The other test done was with 308win ammo. First barrel had 1400 rounds on it. The old lot of ammo had Varget in it. Shot great accuracy wise and no pressure issues. The new lot of ammo had a ball powder in it. Same ammo maker... new ammo when the barrel had around 200ish rounds on it started to produce excessive pressure to the point they pierced 3 primers. An older barrel with Varget powder had over over 3k rounds on it and before it was cleaned had around 550 rounds on it and again using Varget for powder with no issues.

From an accuracy perspective in 308win I know one place if they are pressed for time will go as much as 150 rounds in between cleanings. Usually no more than 50 rounds in between cleanings.

300wm I know of a gov't test facility that went 100 rounds in between cleanings when they ran a specific test in regards to MK248 Mod O ammo and MK248 Mod 1 ammo. It was a barrel life and pressure test... after 90 rounds they fired a controlled lot of ammo thru it.... 10 rounds for accuracy to track the barrels. Most barrels in 300wm you will only get 800-1200 rounds out of them. A standard for special forces was to pull 300wm barrels mandatory at 1500 rounds fired.

The current spec for 300 Norma for gov't sniper ammo is this... .65moa average with no single group to exceed 1moa. 10 shot groups and I want to say being cleaned after every 50 rounds fired but not sure about that. I will tell you 300 Norma is worse then 300wm barrel life wise. I'll say your lucky if you make it to a 1k rounds. Peak accuracy will probably be done by 800 rounds. On the ammunition pressure/accuracy test barrels to hold .65moa spec above... they are pulling the barrels around 500-600 rounds. When that throat starts getting rougher pressure will start to go up and cause issues. Barrel might still hold accuracy for a while yet but when you see the pressure and velocity change it's a warning sign that the barrel is on it's last legs. They are loading to a spec pressure and a spec velocity along with a spec accuracy.

I judge my guns this way... if the barrel will not go at least 100 rounds in between cleanings and hold accuracy... the barrel is off the gun. Most matches I run I'm putting anywhere from 60 to around 100ish rounds thru the gun in a single day. I will clean it that night before going to shoot the 2nd day of the match etc...
 
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