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Gunsmithing Barrel problems W/borecam pics
- Thread starter Ksracer
- Start date
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The barrel in this picture has about 200rnds on it. Load work was easy, and I was getting consistant hits on a 12" plate at 1k yds the first trip to the range.
The barrel in the other pic has been trouble. 150rnds of load work, and the best I can do is 1" at 100yds and the SD has been poor. That picture was taken at 400rnds when I bought the borecam.
Both barrels are from the same manufacturer, and are chambered for the same round,the only difference is twist. My unprofessional opinion, is that the barrel looks like Hammered Dog Shit inside, and either wasn't lapped, or cut with a dull tool. Would anybody else care to offer there opinion before I pull it off and send it back? Thanks
The barrel in this picture has about 200rnds on it. Load work was easy, and I was getting consistant hits on a 12" plate at 1k yds the first trip to the range.
The barrel in the other pic has been trouble. 150rnds of load work, and the best I can do is 1" at 100yds and the SD has been poor. That picture was taken at 400rnds when I bought the borecam.
Both barrels are from the same manufacturer, and are chambered for the same round,the only difference is twist. My unprofessional opinion, is that the barrel looks like Hammered Dog Shit inside, and either wasn't lapped, or cut with a dull tool. Would anybody else care to offer there opinion before I pull it off and send it back? Thanks
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I would send the pics to the barrel mfg and see what they say and what they're willing to do to help you. I'd expect them to say that I (if my barrel) would have to completely clean the barrel, free from copper and take more pics. I would suggest to them, again assuming it my barrel, that they lap the barrel as it appears it slipped through the cracks. I'd expect to pay shipping. While many would say F*&% that...THEY need to pay. It's been my finding that when you start off reasonable, often you get what you really want without asking.
That said, what break-in process did you go through...I'd expect them to ask.
What bullets are you using...different mfg in each barrel? I'm wondering if maybe 1 is just a poor copper. I've run into a situation where 1 particular mfg just fouled the crap out of a barrel...shot OK, just bad fouling.
the above brings up the question of...how does the poor looking barrel shoot?
That said, what break-in process did you go through...I'd expect them to ask.
What bullets are you using...different mfg in each barrel? I'm wondering if maybe 1 is just a poor copper. I've run into a situation where 1 particular mfg just fouled the crap out of a barrel...shot OK, just bad fouling.
the above brings up the question of...how does the poor looking barrel shoot?
Thanks, I sent the pics yesterday afternoon, we'll see what they say.
My break in is 3 shots, clean, a few more shots, clean again, and then several more frequent cleanings before it gets 100rnds on it. Nothing specific though. I hope they don't try to blame it on that, both barrels were done the same way with the same bullets.
It's hard to tell in the pic, but going from right to left, there appears to be a scrape or gouge, followed by a high, shiny spot, and then a copper streak, repeated hundreds of times the entire length of the barrel.
I found the 3" piece I cut off the muzzle end. I fired the first 3 shots to form some brass before I cut and crowned it, and that 3" piece already looks bad from just those initial shots.
Like I said in my post, the barrel shoots like crap, which is what led me to this point to begin with. I'm hoping they replace it.
That appears to be copper/fouling build up. Some copper in the bore is normal. If it's building up like it looks in this picture (like plating) and it's building up on tops of the lands that is usually a accuracy killer. If you clean the barrel really good and start shooting it and the accuracy is going sour in like 12-15 rounds or so then you for sure have a fouling problem. Where in the barrel is that picture taken at?
Now what is causing the problem can be many different things......
Bullets?
Bore finish and or problems?
Velocity?
How it's been cleaned?
Finish of the throat?
Lot of steel? Do you know the s/n of the barrel? This is assuming the barrel maker tracks they're barrels and lots of steel?
All of these can lead to fouling issues but you need to post more information as well as when you talk to the barrel maker give them all of this information as it can possibly help them in figuring out what is going on when you send the barrel back to them.
Later, Frank
Bartlein Barrels
Some other thoughts for ya.....
Relapping the barrel could help/solve the problem but no guarantee.
Also what are you using to clean it and what is your method?
Also speaking for us here and for other manufacturers.....contacting the manufacturer first is what you should do before posting problems and posting pictures. Otherwise conclusions are made and the maker can start getting a bad rap etc....people will start throwing stuff out there like poor machining, bad steel etc.....and with out knowing all the details conclusions can be made incorrectly.
I understand your looking for help but give the maker a chance first.
If they are a decent manufacturer and it's anything they did they should stand behind it.
Later, Frank
Relapping the barrel could help/solve the problem but no guarantee.
Also what are you using to clean it and what is your method?
Also speaking for us here and for other manufacturers.....contacting the manufacturer first is what you should do before posting problems and posting pictures. Otherwise conclusions are made and the maker can start getting a bad rap etc....people will start throwing stuff out there like poor machining, bad steel etc.....and with out knowing all the details conclusions can be made incorrectly.
I understand your looking for help but give the maker a chance first.
If they are a decent manufacturer and it's anything they did they should stand behind it.
Later, Frank
Thanks for taking the time to share, Frank. I'm not trying to bash anybody, I intentionally didn't mention a name. It was just simply the weekend, so I sent them the pics Monday morning and they have requested the barrel back for inspection.
I use BoreTech products with a brush, patch, soak, repeat process. I have cleaned this barrel far more often than any of my others. I can't say for sure that cleaning it improves accuracy, but shots 2-10 after cleaning usually have a low SD, and then it climbs back into the teens, which is another problem I've been battling.
That pic was taken about 15" down the bore, but it looks mostly the same from throat to muzzle. The tops of the lands actually look clean, it's the grooves that are the problem.
1 thing I do remember from chambering it, is that my .2434 diameter throating reammer left a 360deg "ring" at the end of the free bore. Like the reamer was a couple thou larger than groove dia. I should have given it more inspection at the time.
Bullets have been Noslers and Berger's, same lots as the first barrel.
Again, thanks for your time, definitely all good points to consider.
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Ksracer, I figured you we're trying to bash anyone as you didn't list the makers name. I thru it on there mostly so others would read it also. It's just good business to go to the maker first is what I was trying to point out.
If you are using the same bullets as in the other barrel....then we can rule out the bullets and lot of jackets etc....
Sometimes the fouling will usually start about mid way down the barrel as the copper that got shaved off is in particle/dust form and from the heat it gets turned into a liquid type state the.The material is in suspension and as the copper cools it comes out of suspension and will stick to the bore. Again usually it starts in the middle section of the barrel and goes towards the muzzle. Again I say usually but not all the time. If it's starting all the way back at the throat and runs thru the whole barrel like that....it would be interesting to see what the bore looks like after it's cleaned.
A 360 degree ring at the end of the freebore? Are you talking in the grooves or on top of the lands? What I think you are saying is in the groove correct?
Boretech shouldn't be hurting anything. So I'll rule out cleaning from your description.
Later, Frank
If you are using the same bullets as in the other barrel....then we can rule out the bullets and lot of jackets etc....
Sometimes the fouling will usually start about mid way down the barrel as the copper that got shaved off is in particle/dust form and from the heat it gets turned into a liquid type state the.The material is in suspension and as the copper cools it comes out of suspension and will stick to the bore. Again usually it starts in the middle section of the barrel and goes towards the muzzle. Again I say usually but not all the time. If it's starting all the way back at the throat and runs thru the whole barrel like that....it would be interesting to see what the bore looks like after it's cleaned.
A 360 degree ring at the end of the freebore? Are you talking in the grooves or on top of the lands? What I think you are saying is in the groove correct?
Boretech shouldn't be hurting anything. So I'll rule out cleaning from your description.
Later, Frank
Frank, as usual, there is more to the story than can be communicated at 1 time through a single post.
This is a pic of the cut off piece from the muzzle that I was able to find in the scrap bin yesterday. After chambering, i fired 3 rounds through it for brass samples before I cut, threaded, and crowned the barrel. What doesn't show up in this pic well is the surface finish in the grooves. It looks like you tried to pet a cats fur the wrong direction and it stood on end.
As far as the "360 ring". Its not really "in" the grooves, but where the free bore transitions to the grooves. It looked like the grooves were smaller than the straight free bore portion of the reamer, and the 1.5deg leade angle left a "forcing cone" that the bullet had to squeeze through to get into the grooves. Before I sectioned the muzzle piece this week, since it's a 4 groove barrel, I was able to measure the groove diameter with a split ball type small hole gauge. I also slugged it with a piece of lead. I'm consistently getting .3415. I'm not sure if that normal, but it seems small to me.
I started this thread to gain knowledge about a problem, and get some feedback as to possible causes. You have been an excellent source, Thank You again, sir.
Ksracer, First your welcome! this is a 6mm correct? I'm just making sure I got the numbers right.....and your getting .3415" for the groove size or are you trying to measure the throat/freebore area?
I still say the fouling looks excessive by looking at the pictures. and that's what's causing your accuracy issue but now to try and determine what is causing the fouling issue is the hard part.
Later, Frank
I still say the fouling looks excessive by looking at the pictures. and that's what's causing your accuracy issue but now to try and determine what is causing the fouling issue is the hard part.
Later, Frank
My bad. I fat fingered the keypad on my phone. I'm measuring the groove diameter at .2415. I could be off a few tenths either way, but it is not .243. I don't know what the tolerance on bore size is, maybe that's not a big issue.
P.S. I chambered my spare barrel yesterday (it's one of yours) and had a few questions about break-in, so I called. I believe the gentleman's name I spoke to was Mark, he was very helpful. Thanks again.
Ksracer, O.K. .2415" makes sense. If what you measured is truly .2415" then the grooves are at a min. .0015" under size. Could it be causing your problem? Possible. I will say I have shot tight bore and tight groove .30cal. barrels and there is no accuracy difference between a tight bore and a standard bore at least with a .30cal.
If the grooves are truly under size it's going to drive your pressures up. It's going to squeeze the bullet more!
If we can help let me know.
Yes I skipped out early yesterday to so some shooting. Mark is the one you talk to and is an awesome dude! He is primarily a short range benchrest shooter and currently holds 2 or 3 world records! We took him to his first F -Class match last year at the Nationals and has never shot in a match out to a 1k yards and he had a blast. He is now building a F Class gun!
Later, Frank
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I'm certainly no expert, but it sounds to me like they cut the barrel with intentions to lap it to final diameter, then it got missed somehow.... mistakes happen in manufacturing. Is it normal to lap 0.0015" off? Well, actually it would only be 0.00075" per side, but since I'm not a barrel maker, I'm not sure if that's normal.
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Trying to lap that much out of a barrel you are asking for headaches! Finish lapping is meant as a final polish and not really meant to change sizes. Yes it will take a .0001" or .0002" out but if a barrel maker is starting to lap more out especially a .001" and I know some have done it they are going to start having or will be creating bore uniformity issues over the length of the barrel. It's hard to keep the lapping compound to go thru the whole length of the barrel with uniformity. Usually you start bell mouthing the ends of the barrel which leads to accuracy issues.
I'd be interested to know what the bore size is (tops of the lands) as well out of curiosity sake.
Later, Frank
Well, Ups showed up unannounced Thurs with a new barrel for me. Nothing else in the box except a no-charge invoice. I enquired further and they said when they looked at it, nothing really stood out that would have caused it, just that something's can't be explained. I measured the groove size on the new one right at .243. I personally believe the old one was a touch undersized, and the bullets were shedding extra copper as they were squeezed into the grooves. My break in procedure probably wasn't adequate to remove it before it started to build up and it snowballed from there.
Good on the MFG to get you squared away. I think, at least hope, that most makers would be willing to replace a bad bbl .
Nothing is perfect, but some are close. It's the customer service that keeps us purchasing their products.
Nothing is perfect, but some are close. It's the customer service that keeps us purchasing their products.
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