Home Forums Hunting & Shooting AR and Tactical Rifles Fine Scratches in barrel. Fixable? Cause(s)?

I bought a used Remington R-15 that turned out to have a rough barrel bore.When I got it I immediately cleaned it and it seemed like whoever had it before had never heard of bore solvent & patches. It was pretty dirty. It actually shoots fine- I'm able to get 1 MOA 5 shot 100 yard groups with my hunting handloads. What I am seeing with a bore light are tiny, very shallow scratches in the barrel grooves that go straight rather than following the rifling contour. When cleaning the bore I get much more copper fouling than on other .223 barrels. I don't see any pitting. I don't feel and snagging of the patches. When I run a patch down the barrel it just doesn't have that smooth travel I am used to. The last couple of inches of barrel near the muzzle are pretty smooth which is probably why it still shoots decently. I've used some JB bore cleaner but haven't gone nuts using it. Sweet's 762 cleans it up nicely but takes about 5-10 repeats of the wet swab, let sit 5 minutes, dry swabs then repeat until blue no longer shows.

Could it have come from the factory like this? I suspect some dingbat prior owner took a SS bore brush after it but I'd think the scratches would still follow the riflings. Anyone seen this before? Any ideas of the cause?

Should I consider fire lapping it or JB the hell out of it to polish the bore? Should I just get a new barrel? I'm actually willing to live with it since it is accurate enough for the predator calling I do.

If it shoots to your satisfaction, shoot it. I've got a 18 inch cheap-o barrel on an AR that pretty much bug holes with 69 grain GoldMedal ammo, holds minute of coyote or groundhog out to 300 with 55 grain v-max, but is a bear to clean. Borescope shows chatter, reamer marks, scratches, etc. Bore looks like 9 miles of bad road, but it shoots, so I quit using the bore scope and just clean it every couple hundred rounds.

If it shoots, do just that, shoot it. After 6,000-10,000 rounds the barrel will be trash then put a quality barrel on it and be happy you got such great mileage out of a cheap barrel.

Just shoot the damn thing. After a while, the bullets will be enough to fire lap the bore. If you are looking for sub moa 10 shot groups, you may want to just replace it with something else. It entirely depends on what you want to use the rifle for. However, since you already admitted to shooting 5 shot 1 moa groups with your "hunting" loads, id say you are just fine.

Friend just told me getting & using a bore scope was the worst mistake he ever made!

His best shooting Anschutz match barrel looks like crap with "ridges" running the diameter of the barrel all up & down it! It is totally filthy with lead patches randomly distributed throughout the barrel because he never cleans it. It can't shoot good!


But it will clean the metric 50m target with 95+% Xs.

Sounds like I need to "cool my jets" and get on with life. Thanks for the input. I needed that.

There's a whole lot of truth right there

This. In fact I just had a very respected guy scope one of my barrels. Said chamber rough as a corn cob and bore had inclusions all over.. NOT a cheap barrel blank to start with. Think along the lines of Krieger cost etc...

Then said it should shoot just fine though. And on a bit of testing it shows good promise especially for a lightweight tube.

The other thing folks don't need is a chronograph... I can't tell you how much they have lied to me on ES/SD that should be great groups and are not.... I learned right quick use the chrono to find area of MV, if you are maybe over pressure, to get an IDEA of drops and wind drifts. Then trust ONLY what you see on paper at that distance.

Good post Jeff..

Borescope is a good thing, lots of info.

Now, how you interpret and use that info is another thing.

Info is never a mistake. Not understanding and incorrectly applying that info could be.

DF

If it shoots great leave it alone.

I do know one thing - short stroking a metal brush where the bristles turn around in the direction they are being pushed / pulled can scratch a. Barrel... just as you describe.
DO NO DO IT... with a brush. JAG’s are ok. SO many people reverse the direction of a metal brush it isn’t funny....

You can use JB bore paste without harming the barrel to see if it removes the scratches - provided you don’t go nuts with it.
If you want to lap it, you need lapping compound - but you better know what you are doing or you can ruin the barrel


If it were me I’d bore past (JB), and then use ultra bore coat to get the fouling down and leave it alone..

This!

The chrono is a good example - a decent chrono is a vital piece of handloading gear, but some guys get lost in the weeds trying to chase a magic SD number, insisting SD must correlate to accuracy. Knowing velocity and the related statistics is good, but interpreting that info in the wrong way is not.

I see guys at the range doing that chit all the time. They say they are "ladder testing". Looking for the lowest possible sd and es. All the while shooting 5" groups. Then saying, "i dont care what group size im getting now, once i find the best numbers, that will be the best the rifle will shoot with that load". I just shoot the fugger and go with the tightest, most consistent looking load. Generally my chit shoots better too. These new members wont bring their rifles to the clubs shoots either. I wonder why?

I think you said it much better than I did. But same thing. Folks have assumptions. like on a borescope. They expect a mirror finish. What they need is to have an absolute tack driving rifle or 3. THEN get a scope and look and see what you see. Then compare to horrible shooting guns. Assuming you have worked all the other variables on the horrible ones like bedding, crown, loose screws, bad scope, muzzle worn from cleaning rod etc..

And ladder shooting has NOTHING to do with a chrono IMHO. Its looking for a barrel vibration node. No specific speed can cover that...though sometimes I run the chrono at the same time for giggles.

And yes likely came like that. BIL has a Remington AR that has a ROUGH bore. But moly coated ballistic tips shoot in it. Why he won't use heavier ones for less deer damage is beyond me but I digress. It doesn't like barnes ttsx bullets but changing bullets to ones it shoots is cheaper than swapping barrels.

I have fire lapped 3 rifles. Two improved in accuracy the third was unchanged. They all are easier to clean. I plan on shooting a bunch of test loads to work up another accuracy load with a new powder soon. Since the rifle is for hunting it is not a big deal to clean/decopper it every 2-300 rounds which might be once a year. I do more shooting during load workup than in the field (unless they're running!). I don't have a bore scope or chronograph so I rely on 100 & 200 yard groups.

I don't see fire lapping really hurting, though it can take away life of barrel. Accuracy I can't see it ever hurting, and sometimes helping.

When we have issues with fouling we take diamond paste and a cleaning rod to the bore. patch on a worn out jag. 1 and 6 micron IIRC. Though right now I can't recall which is finer...

Cleaning for most shooting is over rated. IIRC there was some research done that more or less says it gets so much fouling and then no more can happen.

I will say if I want carbon gone I shoot a rifle HOT, and then put solvent in it right away. Once carbon is cold and hard it has to be polished out. Seemed to work ok on our ARs every so often soak the bore while ti was really hot. Never did end up with a carbon ring that way.

Coat all my bores now, eventually, with ultra bore coat. Even ones I"ve had salt bath nitrided.

If you want single digit SD use 2520 if you want chitt groups with that low SD use 2520.. I use a chrono to verify speed, usually don’t pay much attention to SD. Now I have had some off the wall SD with RL 15.. I do pay attention to the ES though..

I ignore it all. After all where the holes on the paper are at yardage tells you more than the chrono will.

IE ignore SD and ES.

In the end though if you look at numbers I"m generally never really low or high on them on average... but those sneaky low SD/ES numbers have never related to accuracy on paper at distance for me.