stripes in barrel

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Hi was wondering if anyone ever saw what looks like stripes in a m&p 40,? I just bought a shield 9mm and it looks like the same thing is starting, I have around 300 rds in the 40 and only 100 through the shield.
 
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I'm not exactly sure what you're talking about other than those 'stripes' are the marks left behind from the bullet as it leaves your barrel.

It's a combo of copper and carbon, assuming you're shooting jacketed bullets.

It's totally normal. Other than keeping your chamber clean from carbon build up (esp. in 40cal), you don't need to worry about it. A spotless/mirror barrel does not equal better performance.
 
Thanks for the reply,I'm on my phone right now it will not let me post a picture, it looks as if the barrel had paint in it,the lands are normal but the grooves look grey or bare metal. The barrel is free of copper and lead.I will try to post a picture later once I get home.
thanks
 
Agreed with the carbon jacketed bullets. Unless you are looking at bright orange rusty spots, its sounds like the normal use of jacketed bullets to me.
 
Thanks for the reply,I'm on my phone right now it will not let me post a picture, it looks as if the barrel had paint in it,the lands are normal but the grooves look grey or bare metal. The barrel is free of copper and lead.I will try to post a picture later once I get home.
thanks

You have to use an app like Tapatalk to post pics straight from your phone.

Your situation sounds totally normal. A bullet needs to push into the barrel contours (i.e. 'lands/grooves') for your bullet to spin so it's gonna leave marks.

If you look at a fired bullet it'll have 'stripes' on it also (Google pics is your friend). You'll also notice if you take a cartridge and put the bullet end to the end of your barrel (please take your barrel out to try this), it won't just slide in. The same thing applies from the normal/chamber end because it needs the energy from the powder to force the bullet down the barrel. It's also the reason why if a round has too little powder ('squib'), it can get stuck in your barrel (i.e. not enough energy).

I'd suggest you take a firearms class since most should cover these kinds of topics. As an eye opener, google 'squib load'. It doesn't happen often but it's the kind of thing that can get you hurt when you don't know, what you don't know.

Welcome to the forum.
 

You know, in all the years I've been shooting, I don't think I've ever looked down the barrel of a dirty gun (only looked after cleaning the bore). So tonight I looked at my competition gun (9mm Core with ~ 70K rounds through it) I haven't cleaned it this week. Guess what, I have stripes too. Never would have thought. Probably always been there, I just never looked. So in the end I don't think you have anything to worry about. Now if the stripes persist after you clean the bore, then I might worry. ;)
 
Not being real big on cleaning my pistols after each time they are shot, I looked at mine. Yep, stripes are present.

Cleaned it, no stripes.
 
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Guys the barrels are clean,I noticed the stripes after shooting the guns for the first time new. I brought the 40 back to the store I purchased it at,and was told it looks safe to shoot, but no real answer as to what happened.
 
Copper fouling from copper jacketed bullets. Absolutely normal. And it is a booger to get it out sometimes. In handguns, it's not real critical as far as accuracy goes. You scrub it out and as soon as you fire it again, it's right back. In extremely accurate rifles, such as Bench Rest long range, or Sniper style shooting, those guys try to keep it down to a minimum w/ copper fouling removal products. Past a certain point, enough copper fouling can hurt the fine accuracy of very "tuned" rifles. But hand guns, no. If you can see an extremely heavy build up of copper after a lot of shooting, then get a copper fouling removal product from your local gun/ sporting goods store and remove it. Usually most handguns only foul to a point and then just don't get any worse. The more you shoot, the smoother the rifling gets. Just like a car engine, parts wear in and further wear goes down to a minimum. Most modern handgun barrels can handle well over 10's of thousands of rounds before being worn to the point of accuracy degradation.
Scrub it out w/ Hoppe's #9 and forget it. Won't hurt anything.
Have fun and be safe.
 
Guys the barrels are clean,I noticed the stripes after shooting the guns for the first time new. I brought the 40 back to the store I purchased it at,and was told it looks safe to shoot, but no real answer as to what happened.

It's not as clean as you may think. But the good news is that it is just normal copper fouling and will not hurt anything. I would just shoot it, clean it as you have been and not worry about the stripes. If you tried to remove every bit of copper fouling every time you shoot the gun you would probably do more harm than good.
 
I have been down this road, the only thing that I have found to remove the copper stripes easy and well is to use Break Free Bore Foam, fill the bore and plug both ends. Let sit an hour or three, brass brush out, repeat if needed. Lots of time and brush work if the gun is heavily laden. If not, one easy foaming may be all you need.

I dont worry much about it now, as others have suggested.

DR
 
A factory mass produced barrel for a "service" grade firearm, is not going to come off the line with a nice smoothly cut barrel. They just don't get the same attention a match/target grade barrel gets.

It's not unusual for fouling like that to easily occur while the barrel breaks in.

If the barrel continues to easily or heavily foul, barrel lapping might be in order.
 
Copper removal

What do you use to plug the breach and muzzle?

You can use what's handy, what works and what isn't affected by the copper remover: corks, rubber plugs, modeling clay (that can be tedious to remove), soft wax, or something else your imagination suggests.
Might not even need to plug the muzzle if you can fix the barrel solidly upright.

Hope this helps,
Larry
 
Now that's a clear photo unlike strata's. Normal residuals that get left behind . Clean is still like never fired clean uless you soak in is a dedicated carbon cleaner and copper cleaner. Don't worry about it every handgun will have some amount of material imbedded into the lands and groove of production barrels. Match barrels less but still something is there.

Carbon can be cleaned well with plane ole techron at an auto parts store
Amazon.com: Chevron 65740 Techron Concentrate Plus Fuel System Cleaner - 20 oz.: Automotive@@AMEPARAM@@http://ecx.images-amazon.com/images/I/41vr-MYPT%2BL.@@AMEPARAM@@41vr-MYPT%2BL

Maybe the best carbon cleaner is KG-12
KG-12 Big Bore Cleaner: Metal Protective Coating | Firearm Lubricants | Industrial Coatings

Kroil oil and JB bore paste or also two product to own and use . brownell has videos for how to use it.
 
One thing I try to do when I clean a revolver is that I try and use a larger bore brush than what it says. For instance I use a .40 brush for my .357's. Works great and gets out everything like lead and fouling. On the other hand, I used to take a copper scouring pad, pull off a long piece of what looks like a single strand and then wrap that around the brush. That works just as good. Get a decent brush, scrub it good with Hoppes 9 and then clean it out and it should clean up.
 
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