Gunsmithing tooling marks in barrel

[veezer]

I finally got my 50bmg back from my smith that put my parts together and noticed something really strange. It has a Lilja barrel and at the muzzle end (and down in as far as I can see) I can see tool marks from what looks like where the bore was drilled out (very small lines that run perpendicular to the bore axis). They are in the area where the lands meet the grooves and are about 10 -20 thousands wide. It looks like they were lapped out in the rest of the groove. I surely didnt expect to see them. I used a small pick and ran it across them and I cant feel them, but I sure can see them. Also, about an inch from the muzzle I can see a complete ring of these marks all the way around the barrel on the inside. The ring of marks is also about 10 thousands wide. I tried to get some pics of it, but they didnt turn out very well.

Anyone have any idea why they are there and can anything be done about it?

 

[KYS]

Re: tooling marks in barrel

Shoot it and from your new position you wont be able to see those marks!

 

[Keith Johns]

Re: tooling marks in barrel

Dont rub a pin in there if its steel. Doesnt matter if you can feel them or not.



You didnt notice if they were there before you sent it off obiously?


Not sure what caused it. Maybe a pilot from something your smith used? I dunno. (EDITED: cant be a pilot if the marks are in the grooves)


But hopefully it wont matter. Shoot it and see. I know some people here don't have time to break in their barrels, but it wouldn't hurt for you to shoot n clean 5x+, then shoot a group and see how she does.

I doubt a Lilja would have came with any marks in the bore but I dont know maybe its more common than I think.

 

[CS223]

Re: tooling marks in barrel

I've seen similar marks in button-rifled factory barrels when viewed with a bore scope. Without a photo, I'd say that's what you're seeing. Look like this?

 

[trigger time]

Re: tooling marks in barrel

I cut and crowned a TC the other day that had them bad. First time I have ever seen, or at least noticed them. The main reason the guy wanted it cut and crowned was due to the fact it didn't shoot for crap. Told him that there was a high chance it would not fix it, but he wanted it done. I wonder if that didn't play a very big part in it not shooting.

 

[veezer]

Re: tooling marks in barrel

I didnt notice them until after I shot it and cleaned the barrel really well during the break in process.

Here are a few pictures of it.

 

[Jeepocabra]

Re: tooling marks in barrel

That looks like marks from the love center. Does it shoot well? If so no sweat of not show your smith.

However of they go all the way down the bore that could be caused by a worn out tool when the barrel was rifled or bored out.

 

[300sniper]

Re: tooling marks in barrel

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jeepocabra</div><div class="ubbcode-body">That looks like marks from the love center. Does it shoot well? If so no sweat of not show your smith. </div></div>

i hope the love(sic

) center doesn't leave a ring half inch into the bore on both the lands and grooves.

 

[mcfred]

Re: tooling marks in barrel

Looks like a reamer caught a chip when the barrel was made. If it shoots well then it's probably not a big deal. Kinda strange to see that from lilja though.

 

[2156SMK]

Re: tooling marks in barrel

Perhaps that barrel did not get an inch cut off the raw blank when it was chambered, fitted and crowned?
You would think that everyone knows you are supposed to cut 3/4" or more off the muzzle and perhaps that was there when it was a brand new blank, but Lilja didn't scrap the barrel because they expect the smith to cut an inch off the muzzle...

 

[Thud]

Re: tooling marks in barrel

Veezer,
You shot it how does it shoot. I think you are making a mountain out of a mole hill.
Just shoot it its no big deal.

 

[veezer]

Re: tooling marks in barrel

I've only put two rounds through it so far so I can't tell yet how well it shoots. I already had issues with the fluting having very distinct tool marks in that I had to polish out that Lilja wouldn't fix and now this. It's just disappointing to pay $600 for a quality barrel and have these issues.

 

[Garvey]

Re: tooling marks in barrel

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: trigger time</div><div class="ubbcode-body">I cut and crowned a TC the other day that had them bad. First time I have ever seen, or at least noticed them. The main reason the guy wanted it cut and crowned was due to the fact it didn't shoot for crap. Told him that there was a high chance it would not fix it, but he wanted it done. I wonder if that didn't play a very big part in it not shooting. </div></div>

He's convinced (after some nudging from me) that he needs to foul that barrel. I asked him how much he's cleaned it, what do ya think he said? "I clean it after every time I shoot it." I informed him, of those of us that shoot much farther than he ever will, that we don't do that, and that fouling that barrel will probably help tremendously. I may be the one to work up a new load for that rifle too, by the way. So we've got some shooting to do.

 

[Slinky001]

Re: tooling marks in barrel

The mark could be from a piloted crowning tool that someone used to crown the barrel.

You might want to ask your builder if he used a single point tool or a piloted one!

Brian

 

[tuckybill]

Re: tooling marks in barrel

I had a Bartlein in .257 Roberts put on old mauser here. When I got it back from the smith first thing I noticed were the circles scratched inside the bore near the muzzle. Smith told me that was where the pilot had been in the barrle when he crowned it. Ugh. In my case they only go down about 3/4ths inch...its a long 25 inch barrel so "someday" I can get it cut and re-crowned. Rifle only shoots so so. I think the pilots that all the smiths are using to damage these hand lapped barrels only go in for about a inch at most. If its all the way up and down your barrel it might not be the pilot.

I'm not a fan of Lilja barrels but I doubt they sent one out like that. Did you look and see if they were there before you sent it off? I guess it could be one that they just didn't lap it all out good enough.

I just returned a Green Mt. rimfire barrel that was perfect in every way but had deep gouges on the the lands that ran straight with the barrel axis. So deep that it wasn't where someone had dragged a bore rod through it. Had to be made under machine power. Very strange. No wonder so many bench shooters do their own barrel work and some even end up making barrels! I just wish they would remember the reason why they got in the business after they ARE in the business. Good luck with the Lilja.

 

[300sniper]

Re: tooling marks in barrel

a pilot rides on the lands so it shouldn't mark the grooves.

it could be caused from swarf when the muzzle work was being done. it could also be a mark from an test indicator stylus. i'm leaning toward swarf being the culprit since i think there should be a gap in the mark when tip of the dti stylus jumps up onto the lands.

i don't think i'd sweat it unless it doesn't shoot.