Does a clean bore affect impact and accuracy?

[grapemeister]

I shoot nothing but lead these days, and even after a 300 round practice I see know difference in accuracy. I run a dry brush through the barrel after practice or a match to take care of any leading. I've gotten lazy in the past and have gone 2 or 3 practice sessions or matches before cleaning, and still didn't see a decrease in accuracy.

For the most part, I believe the bore is self cleaning when shooting jacketed rounds. When I shot jacketed rounds I didn't really feel the need to clean a barrel, but I did every once in a while just in case I was getting a build up. If for no other reason, it was because of the brain washing I received in the army.

In the army I think we spent way too much time sitting around cleaning M16 barrels. Having said that, I don't believe you can clean too much or "over clean", unless improper tools, and really nasty chemicals are used. A basic nonhazardous cleaning oil and a good brush causing more damage to a barrel than thousands of rounds of jacketed bullets, I don't buy that either.

[Reshoot]

We at Schuemann Barrels regard a barrel to have been substantially worn out when the bore radius is enlarged by 0.0005 inches (a bore diameter increase of 0.001 inch).





http://www.schuemann.com/Portals/0/Documentation/Webfile_Barrel_Cleaning.pdf

Seriously? Schuemann Barrels considers a barrel worn out when the bore diameter increases by .001" (one thousands of an inch)?

Waayyy back when I worked for Imperial Clevite (manufacturing precision engine bearings) most bearings were produced with a tolerance of +/- .0005" (that is one half of a thousands of an inch over or under specifications).

Some were held within +/- .00025" ( that is one quarter of a thousands of an inch), like the 99% pure-silver-lined Pratt & Whitney aircraft engine bearings.

So, Schuemann's production tolerances would have to be even tighter than those for precision engine bearings.

Please, enlighten us . . . what are Schuemann's production tolerance's for the bore on their barrels.

Edited August 22, 2013 by Reshoot

[jimbullet]

I use heaps of lead projectiles and I had thought, given the fouling lead causes, that it is a necessity to clean the barrel after at least every say 500 rounds. I use a brass brush head with a plastic cleaning rod.

Following this thread and even Brian Enos himself said, that they dont clean the barrel itself but rather only the chamber, will that essentially be the same if I am using lead projectiles?

Copper projectiles, i.e. FMJ, CMJ's do not produce too much fouling in my experience - hardly at all but lead sometimes is seen on the edge of the rifling grooves.

I used to after every session just shoot a couple of FMJ's which made the bore relatively clean enough, but someone told me that by doing so, you are increasing the pressure in the barrel as the projectile is pushing all the lead and fouling which could be dangerous. Any thoughts?

[grapemeister]

I used to after every session just shoot a couple of FMJ's which made the bore relatively clean enough, but someone told me that by doing so, you are increasing the pressure in the barrel as the projectile is pushing all the lead and fouling which could be dangerous. Any thoughts?

I don't do it very often, but on occasion when I happen to have a jacketed round in my range bag, I'll run one through the barrel, and it usually cleans everything out.

Is it safe? I think it depends on what kind of leading in the rifling you are getting. If it's the kind that can usually be pushed out with a few swipes of the brush, then there should be no problem running a jacketed round through it. When I get the kind of build up that takes a lot of work to get out, I don't feel so comfortable running a jacketed round through the barrel. Keep in mind that what may look like a bunch of lead in the barrel could actually be carbon, burnt powder and other crap, and may not be leading.

The really hard leading, the kind we need to be concerned about, usually takes a long time to build up. You should start seeing it before it becomes a real problem. Be prudent in inspecting the barrel, take note of what is going on, and you should be ok.

[Bart Solo]

......after all those years in the Army cleaning my weapon to the point of surgical clean.

Roger that, Tom!

Even before I received my draft notice, I was taught the importance of cleaning and maintaining a firearm, to EXTEND the life of that bore. They started me out with an M-14 that was . . . gawd, who knows how old. And, all those recruits before me that cleaned that barrel as thoroughly as I did. I'll bet that rifle will still shoot true, wherever it is.

Then came the M-16, which I cleaned thoroughly as well. Let's see, that was 1968 and I doubt the rifle has been re-barreled yet! Of course, the military issue 1911's were cleaned just as thoroughly. The claim excessive cleaning will shorten the life of a barrel I can only describe as . . . well . . . hog wash!

I am 65, my father left me firearms that belonged to his father and they still drive tacks. Oh, and the bore on every one of them gets a thorough cleaning after every shooting session. Long gun, handgun or shotgun . . . they all get a thorough scrubbing. Shorten the life of a barrel . . .

I am the same age and have the same habit.

I tell people my dad is reponsible for my habit of cleaning every bore after every shooting session. My dad was a job shop machinist and a WWII vet. He was old school when it came to keeping machinery of all kinds clean. He was especially careful to make sure his sons cleaned their firearms after every shooting session. Old habits die hard.

[Chris_C]

Reshoot, if Schuemann is pulling a button through their barrels to rifle them I imagine the tolerance is extremely good. As long as the button is checked for diameter frequently and replaced when it is reduced then the process should be very consistent.

[Reshoot]

Reshoot, if Schuemann is pulling a button through their barrels to rifle them I imagine the tolerance is extremely good. As long as the button is checked for diameter frequently and replaced when it is reduced then the process should be very consistent.

What is the decimal equivalent of "extremely good"? I serious! Schuemann Barrel has established the fact that their barrels are "substantially worn out when the bore radius is enlarged by 0.0005 inches (a bore diameter increase of 0.001 inch)".

Using this information, I now know that a 0.355 inch Schuemann barrel is considered worn out when that bore reaches a diameter of 0.356 inches. So, that bore diameter is extremely important, right down to one tenth of one thousands of an inch. Otherwise, I could be buying a barrel with a diameter of 0.3555 inch, making it half worn out before the first shot.

Let me put 0.001 inches (one thousands of an inch) into perspective. Pull a piece of paper out of your printer and focus on the edge. How thick would you guess that sheet of paper to be?

The paper in my printer is 0.004 inches (four thousands of an inch). Remove 1/4 (one fourth) of that much material from a Schuemann barrel and the manufacturer considers their product "substantially worn out".

Now, you see how critical one tenth of one thousands of an inch is?

[Chris_C]

My engineering career also helps me understand how critical 0.0001 can be, given the application. This is not a machining procedure they are doing as far as I know. They are taking a hardened steel button and pulling it through a drilled bore. As I see it, as long as they keep the diameter of their buttons in check and toss them when they are worn it should be easy for them to hold the tolerance. It's not exactly challenging to measure and sort button diameters.

Schuemann has one of the best reputations in pistol barrels. They are certainly doing something right to keep the following they have.

[Reshoot]

My engineering career also helps me understand how critical 0.0001 can be, given the application. This is not a machining procedure they are doing as far as I know. They are taking a hardened steel button and pulling it through a drilled bore. As I see it, as long as they keep the diameter of their buttons in check and toss them when they are worn it should be easy for them to hold the tolerance. It's not exactly challenging to measure and sort button diameters.

Schuemann has one of the best reputations in pistol barrels. They are certainly doing something right to keep the following they have.

And that tolerance is . . . . ???

[jimbullet]

I used to after every session just shoot a couple of FMJ's which made the bore relatively clean enough, but someone told me that by doing so, you are increasing the pressure in the barrel as the projectile is pushing all the lead and fouling which could be dangerous. Any thoughts?

I don't do it very often, but on occasion when I happen to have a jacketed round in my range bag, I'll run one through the barrel, and it usually cleans everything out.

Is it safe? I think it depends on what kind of leading in the rifling you are getting. If it's the kind that can usually be pushed out with a few swipes of the brush, then there should be no problem running a jacketed round through it. When I get the kind of build up that takes a lot of work to get out, I don't feel so comfortable running a jacketed round through the barrel. Keep in mind that what may look like a bunch of lead in the barrel could actually be carbon, burnt powder and other crap, and may not be leading.

The really hard leading, the kind we need to be concerned about, usually takes a long time to build up. You should start seeing it before it becomes a real problem. Be prudent in inspecting the barrel, take note of what is going on, and you should be ok.

How long are we talking about if the pistol is on a steady lead projectile jacket at a major power factor? 1,000 rounds?

[grapemeister]

I used to after every session just shoot a couple of FMJ's which made the bore relatively clean enough, but someone told me that by doing so, you are increasing the pressure in the barrel as the projectile is pushing all the lead and fouling which could be dangerous. Any thoughts?

I don't do it very often, but on occasion when I happen to have a jacketed round in my range bag, I'll run one through the barrel, and it usually cleans everything out.

Is it safe? I think it depends on what kind of leading in the rifling you are getting. If it's the kind that can usually be pushed out with a few swipes of the brush, then there should be no problem running a jacketed round through it. When I get the kind of build up that takes a lot of work to get out, I don't feel so comfortable running a jacketed round through the barrel. Keep in mind that what may look like a bunch of lead in the barrel could actually be carbon, burnt powder and other crap, and may not be leading.

The really hard leading, the kind we need to be concerned about, usually takes a long time to build up. You should start seeing it before it becomes a real problem. Be prudent in inspecting the barrel, take note of what is going on, and you should be ok.

How long are we talking about if the pistol is on a steady lead projectile jacket at a major power factor? 1,000 rounds?

Sorry, I can't answer that question. I only load 9mm at minor power factor.