Barrel pitting?

Here is a link to a video I shot of my Winchester Miroku Model 94 Sporter. About halfway down the bore pitting seems to be present. My buddies with vastly more experience than I have determined its caused by careless factory work. The gun shoots ok and I'm still looking for a good load that shoots 3-4 inches at 100 yrds. Its had 200 rounds approx. through the bore and I keep it as clean as I can. Is this what we can expect these days from the manufacturers?

 

My circa 1983 AE still has a mirror finish. Nothing close to what you have in that barrel. I would contact Winchester and see what they say.

 

Uhg Definitely trashed and you need a new barrel. Doesn’t matter that it shoots well.. You saw bore imperfection & now you will forever be convinced the barrel is TRASH…maybe even dangerous!!

Or. Maybe not. Maybe it’s just barrel surface imperfection that is very common among manufacturer’s barrels. Maybe it will continue shooting better as you form a load it favors. And maybe, just maybe, you would never have any inclination of any problem or reason to ever scope the bore. This is why I recommend people Not use a borescope until they truly understand steel condition and how slight imperfections doesn’t doom the barrel. People convince themselves the barrel is trashed. Sometimes before they fire a single round.

Yeah, we see this in many barrels. It’s not just a “from now on” thing. It’s always been. I could show you some Savage 110 factory barrels that look horrendous! Yet, the guns shot very well.

 

All my other Mirokus are spotless. I did find a tiny bit of surface rust on my circa 80's 52B but it cleaned out without so much as a burnish. The rust was probably on me as my dessicants went south and I had to bake them clean again.

 

I'm not convinced of anything yet and I will keep shooting the rifle as I am not afraid of it. If this is the norm then thats what it is. I think the borescope is a great addition to my equipment as I never had one before and it lets me know how well I am cleaning and bore condition. The gun stays with me forever in any event. I contacted Winchester and have not received a reply yet. If nothing happens then oh well. I am taking it to the range tomorrow and trying out some low level 4198 loads and then a borescope right after so I can see what fouling has occurred. I appreciate your input.

 

Every rifle is different, but my model 94 ae doesn't usually like reduced velocity loads. My most accurate to date is the 160ftx at about 2290fps using Lever Evolution powder. It is sub moa with this and just barely better than the factory loads.

 

Sometimes chunks of metal get pulled out by the button in button rifled barrels, but that is a particularly bad example, and a sign of poor QC. Its biggest downside is your barrel will probably foul quicker than a smoother one. I second contacting Miroku.

True, but sometimes its better not to know. I've discovered a couple of pitted barrels too. Now those rifles, who I liked previously, have "something wrong" with them. They are still good shooters though.

 

Ive had way worse barrels than that shoot fine...MOST of my carbon barrels end up looking like that before too long simply because of where I live.

 

This is a timely post. Just yesterday, I was cleaning my Dad's JM (circa 2009) Marlin 336 .30-30 after developing a load. I found two loads that shot under an inch. However, I decided to inspect the barrel during cleaning as it felt "rough" when pushing a patch. It looked the exact same as the OP's barrel. There was no pitting beyond the second half of the barrel. I had figured Dad hadn't cleaned it and stored it in a high-moisture area. However, the gun probably hadn't been shot more than 40 times. It's concerning that the bore is pitted but it shot great with max loads of LVR and IMR3031 and two different bullets.

 

This is unacceptable for a new rifle. Contact Winchester and see if they will make it right and please let us know.

 

Take the bolt out and get some J & B bore paste and put it on a new bronze brush and go to work on that pitting. It will smooth up and afterwards it will get smoother from shooting.

 

I didn't see anything in the bore that seemed to be caused by careless factory work, but pitting caused by either lack of cleaning, or poor cleaning/protection techniques. Pitting is caused by lack of TIMELY cleaning and/or lack of metal protection in humid climates. After bore solvent is used, no protection is afforded, unless it's coated with protectant like RIG. Bore solvent will NOT protect bore metal from corrosion in humid climates.

 

A "good load"? Try 32 grains of W748 under a 170 grain FNSP such as Speer Hotcore. My old "Jack handle" (1949 Win 94) shoots 1 5/8" three shot group at 100 yards.

 

Cleaning is not an issue. I have been successful for 50 years and never had a gun with that type of pitting and none of my other guns in the same safe for 30 years have developed this pitting. I did have a small section of surface rust that came off easily from my 52B barrel bore. It was about 3/8 inches long in only one groove. My guns don't suffer from neglect as I clean after every use and oil. Winchester is 4 days out on my first email to them, so I'll wait a bit longer. If they can remedy it then so be it, if not I'll just shoot it anyway. I will try that 748 load at 32 grains to see if the group tightens up. I have a load at 35.6 and it isn't there yet so less is more sometimes with a 24-inch barrel over a 20 inch-carbine barrel. Oh, this is also in 32 Win Spl.

 

I generally suggest calling a company first then using their website warranty portal after you speak with them rather than simply emailing a general box. That way you can reference the call and hopefully get a name of someone as your point of contact.

1-800-333-3288 or 1-800-322-4626.

https://firearmservice.winchesterguns.com/

 

I've seen that in several barrels.I almost sent one back to Shilen when I saw the exact thing in it.That barrel is one of their Select Match in 280AI.The best group out of it so far is a .194 for 5 shots at 100 yards.Shoot one round through it and those pits are gone.I only clean it with patches because It gets basically no copper in it.I bet that barrel will shoot just fine.Bore scopes can let us see things we ordinarily wouldn't worry about.I don't have one,nor do I use chamber gauges.They cause more worry than they fix.The target tells me what I need to know about a barrel.

 

Ross Seyfried did a write-up many years ago about an old and very collectible rifle with a "bad" bore. It had been through half-a-dozen experts who all had measured it, scoped it, and declared it dead. Ross did the one thing no one else had: give it a thorough cleaning, then take it out and shoot it. And of course it turned out to me one of the more accurate rifles of its type that Seyfried had seen.

Which is a long way of saying that I agree with your opinion of bore scopes: they can be useful tools in some circumstances, but seem to be responsible for more than their share of unhappy hobbyists.

 

To the OP: the one question I always ask when this sort of thing comes up is "Would you be satisfied with the rifle if you'd never scoped it?"

In other words, was the rifle a problem and the scope a diagnosis? Or did you not realize you had a problem until you scoped it? That's how I would make the decision regarding sending it back or not.

 

No, the rifle simply hasn't been accurate enough. I never thought the barrel would be in question. The bore was brilliant with a bore light, flawless appearing. The borescope on the other hand gives more data. The borescope is just another tool. After talking with Winchester today I'm going to hold on to it for another month to see if I can dial it in. If I find the magic formula it stays home. If I can't it goes in for a look by Winchester. Thankyou everyone for the input. The rifle is below. The peeps helped with sight picture.

 

That is a gorgeous rifle. I hope it turns out the way you want.

 

I'm gonna buy a bore scope just so I can show some of you exactly what cratering looks like in VN Era opposition barrels

It's makes those look like minor surface erosion . However IF that's a New Barrel with #200 rounds down it , I'd say the Factory had better have an explanation !!. It appears that metallic debris was in deed pulled with the button jamming it into the bore ,thus scoring the finish .

 

A bore scope is cool. It made me realize how many truly sub moa rifles have terrible looking bores.
It also showed clean isn't really clean.

 

The amount of energy expended to push a bullet down a 20” rifle bore at rifle velocities is pretty huge, and variable, for a production made gun.

So when folks get wrapped around the axle on some barrel pitting, or heaven forbid case neck tension, I chuckle. A polished and lapped bore is different story.

In OP’s case, I agree a target and chrono (if available) will tell if the barrel is ok.

 

Precisely. However, just DON’T let it be concerning. This is what I was talking about. You said yourself, two loads shooting SUB-MOA, and yet, you are concerned with some flaws inside the barrel which can’t be seen away from using a Borescope. Look, I could understand if it were a gun that shot very well, but had a BIG, NASTY portion of rust, or ugly pitting on the OUTSIDE of the barrel! Again, doesn’t affect the accuracy, but MAN… what an eye-sore! THIS , however, is only an “eye-sore” in your mind. You just need to forget what a Borescope shows you, without the firearm showing any problem. You’ll end up fixating on it endlessly.

 

I don't think that is humanly possible. It's like seeing a horrible train wreck, you can never get it out of your mind. And mass produced barrels are never perfect.

I bought 2 AR15 barrels recently. One was a internet 1:8 HBAR and the other was a 1:7 from a local manufacturer. The first had a pretty smooth bore with a few small pits which I attributed to the button. The second had more pronounced tool marks and a couple of the lands had gouges which I also thought must have been button related. So I took it back and had borescope pictures of both. I spent some time in the shop with the foreman, and we looked at my barrel through his borescope. Long story short, they gave me a new barrel but I'm sure after I left they probably talked about the dick with the borescope. They new barrel didn't look much better than the other one BTW.