Gunsmithing Barrel Bore Defect?

[Phil3]

I inspected a never fired barrel for an AR15, and I found what looks like a pit or small group of scratches about 3/16" inside the bore. There are two others, but not as big as the largest one. A Q-tip will not snag on it, but you can can feel it if you run the end of a small plastic tube (long nozzle on spray can of Brake-Kleen) over it. Feels rough.

I don't think this is right. ??? Also, the muzzle end does not appear to be finished. What's up with the smaller bevel cut right at the bore?

- Phil

 

[Kogapsp]

Re: Barrel Bore Defect?

Contact Krieger about the barrel. Is the imperfection at the muzzle or the breech end? Krieger stands behind their product.

kn

 

[Phil3]

Re: Barrel Bore Defect?

It is at the muzzle. I contacted Krieger...waiting for their response.

 

[Kogapsp]

Re: Barrel Bore Defect?

Hmm never seen that before.. Looks like the cutting tool went to deep.If it has anymore defects inside the barrel or send it back to have it re-crowned. Easy to do if you have a lathe.

 

[cut rifled]

Re: Barrel Bore Defect?

Looks like they used a piloted crowning tool and the bushing was a little to tight. I would just shoot it and see how it shoots if it shoots good don't worry about it.

 

[Phil3]

Re: Barrel Bore Defect?

I may just shoot it, but before I use it, want Krieger to comment on it. I am not sure what they will say if the barrel is used. This rifle was built to shoot as accurately as possible, and not to a predetermined acceptable level. As such, I would like to have everything exactly right. Also, if it does not shoot well, how can I know the barrel is at fault?

Would not the pilot rest on the lands and not contact the bore. The affected area in the bore is in the groove.

- Phil

 

[BLAWTON]

Re: Barrel Bore Defect?

Thats not a cutter mark its a gouge from something else. Looks like something that happened when it was being chambered and crowned. Like paul said it might not make any difference because of where its at being so close to the muzzle. I highly doubt it was anything kreiger did though. If it was a problem in the rifling process then there should be more of them in down the barrel.

 

[Thud]

Re: Barrel Bore Defect?

Have your smith cut 1/4" off the muzzle and recrown and go on down the road. It's look like the person who crowned it stuck thje cutter to far in and nicked the wall of the barrel nothing to cry about.

 

[Phil3]

Re: Barrel Bore Defect?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: NotAGuru</div><div class="ubbcode-body">I highly doubt it was anything kreiger did though. If it was a problem in the rifling process then there should be more of them in down the barrel. </div></div>

The barrel came out of the Krieger package as shown in the photo...they definitely did this. There may be more defects down the barrel, but I do not have the equipment to inspect. There are a couple more much less severe nicks in the barrel near the muzzle.

- Phil

 

[Phil3]

Re: Barrel Bore Defect?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Thud</div><div class="ubbcode-body">Have your smith cut 1/4" off the muzzle and recrown and go on down the road. It's look like the person who crowned it stuck thje cutter to far in and nicked the wall of the barrel nothing to cry about. </div></div>

I could have a gunsmith do as you suggested, but do not feel it is appropriate for the customer to spend more money to to fix a defect in a new product. It may be faster to do as suggested.

Krieger has not responded to my e-mail and does not answer the phone...unusual for them. They may be closed today. Will see what they say tomorrow.

 

[BOLTRIPPER]

Re: Barrel Bore Defect?

gunplumbers that jock up a blank will most always take off something from each end of the barrel....the exit hole usually gets wacked the the greater length....because of what you see....the manufacturing tooling got to hang on to something during the process of being made.....and due to the reciprocating motion of things.....the muzzle end gets the most in-and-out...

 

[Thud]

Re: Barrel Bore Defect?

Bolt you have a way wit woids....

 

[Phil3]

Re: Barrel Bore Defect?

I spoke to Krieger. According to them...,

The marks (scratches) are the result of using a crowning tool. Normally, the marks are minor and if they pass inspection, the barrel is shipped to the customer. The marks on barrels that pass inspection are very light, smoothing out and disappearing with barrel break in. The marks were not lapped out as excessive lapping can degrade accuracy and damage the crisp crown. The marks generally do not present a performance problem. It was noted that such marks are highly reflective and may look worse than they are.

They said a crowning tool is used to provide a uniform crown, and that it is a little easier and faster to accomplish that with the crowning tool.

The stated using a boring bar many times would require an additional set-up to assure that the crown is uniform 360 degrees around the bore and that the pilot on the crowning tool takes care of this a little quicker.

Was told the volume of barrels produced sometimes requires use of production type methods that still preserves their quality standards.

I am no machinist, and don't know how these tools and the process work, but this is what Krieger told me. Perhaps someone more knowledgeable than I could comment.

It was felt that after learning of the parts in my rifle, and with use of this barrel and quality ammo, the gun should be capable of .5 MOA or better (if I can do my part).

I was asked to shoot the gun and report back on performance, assuring me they stand behind their product and want to be sure I am satisfied.

Will advise on performance.

- Phil

 

[BOLTRIPPER]

Re: Barrel Bore Defect?

come to think of it ...i got a hart that got some trench marks near the business end....it do real well..

well run with it....you are on record as reporting the hairball....if it don't group just remind them of YOUR cost of chambering and crowning.

 

[Hateca]

Re: Barrel Bore Defect?

That's exactly what it looks like. The nick was caused by the cutter hitting the barrel aft of the pilot on the cutter. This is usually caused by the barrel not being properly indicated for run-out and only hits the barrel on one side.

This shouldn't have any effect on accuracy and will most likely disappear after a few rounds down the barrel.

 

["Partridge"]

Re: Barrel Bore Defect?

man i dont know.i would not be happy with that barrel.i hav not purchased alot of custom barrels but none of them had any noticable marks like that.you get what you pay for.and i know that you payd for a quality barrel as close to perfect as you could afford.krieger is reputed to be top of the line.i think i would have to return it and ask for a replacement or refund.just my two cents.that would bug the piss out of me knowing there was a little defect in the muzzle.

 

[Phil3]

Re: Barrel Bore Defect?

The barrel was made to my specs, so not sure I could even return it, since Krieger has deemed it OK. At least until it seen how well it shoots.

- Phil

 

["Partridge"]

Re: Barrel Bore Defect?

I would still talk to someone in customer service. Unless you specified that you wanted a bugger in the end of your barrel I would not be satisfied. Before I shot it I would definitly come to some kind of terms with the guys at Krieger. Within the realms of reality, you are a paying customer. A customer that thought they were getting an above average product based on their marketing. I would rather keep a customer than run him off. We just purchased a Shilen barrel probably for about half of what you paid that looks superb from one end of the barrel to the other. We just hope that it shoots as well as it looks. Good luck with your barrel and we hope that it shoots as well as Krieger states it should.

 

[Phil3]

Re: Barrel Bore Defect?

UPDATE: I was talking to Krieger about reloading dies for their chamber and mentioned the mark in the barrel. I was told that was not so uncommon due to use of a crowning tool (as stated before), but it came to light, such a mark would be on the land. I said my mark was in the groove. I sent another photo to best illustrate that, and asked if that changed the last recommendation on what to do with the barrel (shoot it).

Krieger contacted me via e-mail and voicemail, within an hour of me contacting them. They said a mark like that in the groove is not normal and something they want to see. They do not know how it got there. They said they will prepare a replacement barrel, personally inspect it carefully, and send it out asap in protective packaging. I was asked to send the existing barrel back.

While the barrel should not have left Krieger in the condition it did, the entire experience illustrates solid customer support and an unwavering willingness to stand behind their product and make things right for their customers. I will be ordering future barrels from them.

- Phil

 

[Blackhawk95]

Re: Barrel Bore Defect?

Cool, Im glad they took the time to discuss the problem and resolve it so quickly..

Thats the kind of people you want to deal with.

Jerid

 

["Partridge"]

Re: Barrel Bore Defect?

further proof of getting what you pay for.i am glad that krieger is standing behind the barrel.

 

[wnroscoe]

Re: Barrel Bore Defect?

Pushing the numbers Krieger does, one's apt to slip by every now and then. I've had the opportunity to chamber numerous barrels from numerous manufactures. I can say this without reservation or regret, Krieger is the absolute king. Purchase with confidence. I ordered two more today, five total in under a week. I’ve never received a bad one but, like I said, ones bound to slip through every now and then.

 

[Phil3]

Re: Barrel Bore Defect?

I spoke to two people at Krieger, and both came across as genuinely concerned, and agreed to make things right. They want to see my existing barrel, for examination and an understanding of what may have happened.

Krieger is decent sized, having 35 employees and annual sales of just under $4,000,000 a year, according to records found on the Internet. Very well have gotten a bad one out of the many.

- Phil

 

[Tangodown911]

Re: Barrel Bore Defect?

How much will it cost you for the swap in smith labor? What did they say about that?

 

[Phil3]

Re: Barrel Bore Defect?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tangodown911</div><div class="ubbcode-body">How much will it cost you for the swap in smith labor? What did they say about that?</div></div>

I don't know, I never asked. I installed and removed the barrel. The gas block, gas tube, free float handguard, bipod, and barrel nut have to be dealt with on install or removal. Either way, it takes about 10 minutes (really). I might ask them about shipping charges to send the barrel back.

- Phil