If a rifle shows some very light pitting in a otherwise shiny bore, would these pits have a noticable negative effect on the rifle's accuracy?

Sure. Any irregularities in a bore can cause accuracy and pressure problems. It can cause heavier than normal fouling which is known to raise pressures and affect accuracy. Depending on the gun, and if the pitting isn't too far advanced, you might find a shop to lap the barrel for you.

I have a M99 Savage in .250 Savage that has a barrel full of light specks of pitting. Kind of a salt and pepper effect. It copper fouls bad because of it. Shoots under an inch at 100 with 75 gr. Sierra hp, 1 1/4 with 89 gr. Speer Hot Cores. I've wondered many a time what it would do with a better barrel.
I doubt it shoots up to what it would have with a perfect bore, but many times they'll still shoot very well.

It depends. You'd be surprised at 1) how many rifles have pitted barrels (in one state of the other), and 2) how well some rifles shoot in spite of this.

I don't think you can conclude "my barrel is pitted, therfore it won't shoot accurately".

- mike

quote:

Originally posted by reindeer:
If a rifle shows some very light pitting in a otherwise shiny bore, would these pits have a noticable negative effect on the rifle's accuracy?

1. I've never seen pitting in a bright bore.....(I suppose there's always a first time)

2. Pitting can never be beneficial

3. Life don't come with a set of rules that use never and always.....and with guns it gets worse!!!

I, personally don't think what you described would have a detrimental effect on accuracy. (see item #3 above)

I agree with with Malm, but I have seen a rifle or two that shot very well with sewer pipe bores. One that stands out was an old "bubba'd" Springfield. The throat was gone, the rifling at the muzzle was worn, and it looked like somebody used coarse emory cloth for cleaning patches. Long story short, that rifle would shoot between 1 and 1 1/2 " regularly. Ya just don't never know.

quote:

Originally posted by reindeer:
If a rifle shows some very light pitting in a otherwise shiny bore, would these pits have a noticable negative effect on the rifle's accuracy?

Not necessarily (if shooting jacketed bullets!!). I had a Norwegian Krag with some noticeable pitting in the bore, but it shot 1" 5-shot groups pretty often with Sierra 140-grain bullets and a heavy load of H4831.

I never tried it with cast bullets, however.

As Vapodog said, "pitting can never be beneficial", but it is not necessarily a death sentence, either. You just have to shoot it and find out!

ever make love to a girl with freckles or moles? I have a prewar Merkel double rifle with frosted bores, looks like the bed of a dry lake. one barrel still shoots way under an inch, other just at an inch. problem with this rifle is that the two groups dont overlap with any known or tested load. they act like the north and south poles of a magnet when brought together. best is two groups of one inch about two or three inches apart.

dont knock freckles or frosted barrels.

quote:

Originally posted by Jameister:
ever make love to a girl with freckles or moles? I have a prewar Merkel double rifle with frosted bores, looks like the bed of a dry lake. one barrel still shoots way under an inch, other just at an inch. problem with this rifle is that the two groups dont overlap with any known or tested load. they act like the north and south poles of a magnet when brought together. best is two groups of one inch about two or three inches apart.

dont knock freckles or frosted barrels.

We're talking about pitted "Bores" with a "B". If you're running your projectile over freckles and moles, your way off target!

only on an AR thread can one go from pitted bores to freckeled whores in just a couple posts!!!

I once knew a freckled whore with a pitted bore. Shot well over an inch though.

I have seen very pitted bores shoot just fine on a hunting gun. I would not worry about it unless the hting grouped over 2" at 100 yards

This is exactly why I refuse to get a bore scope. I have had various guns that shoot fine with crappy looking bores. Knowing there is a real ugly defect somehow spoils the overall fun.

Its also why I never, ever take the bag off.

I've got an old Vz-24 Mauser in 8x57. The throat is gone and the bore is badly pitted for first 1/3 of its length. It still shoots 3 shot groups under 1.5" at 100 yards with the 2x scout scope! However the velocity is 300 to 350 fps low.

quote:

Originally posted by reindeer:
...would these pits have a noticable negative effect on the rifle's accuracy?

Hey Reindeer, If you are shooting at things up close(like it seems most of the responders are) then it "might" do OK. The pits will gather Jacket Material at a differential rate, meaning the Bore Condition will be changing quicker as you shoot more shots.

Out at the l-o-n-g-e-r distances, the probability increases that the groups will open quicker due to higher, constantly changing, abrasion patterns on the Bullets.
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All the "probabilities" don't amount to a hill of beans though, only On-Target results.

Shoot your rifle at the distance you intend to take shots at Game and see how well it groups. Put 2-3 shots in each Target at that distance. Then when you get done, stack the Targets atop each other in front of a bright light and see if the pattern is shifting. And of course see if the group is opening.

If it provides the accuracy level needed for the Game you Hunt, then enjoy it the way it is, re-barrel it, or trade it off.

Who ever had the rifle before you probably believed it was a "waste of time" cleaning a rifle. I've seen a few recent threads concerning that topic. One referenced John Barsness as saying, "Cleaning is a waste of time." I didn't read the article and did not see anything he has said on it though. If he actually said that, he has a whole lot to learn.

Now you know why I clean my barrels every time they go outdoors and occasionally even when they don't.
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Don't tell any of your friends about having the Pits, it makes the person with a Pitted Bore look like he just has no concept about how to care for a rifle - if it was New when he got it.

Best of luck to you.

Accuracy is nothing more than consistency. Everything needs to occur exactly the same for each shot. The throat and the muzzle are where most "inconsistencies" occur. What is in between them isn't as important.

As stated above, pits will lead to quicker fouling, which will cause variations in the bore. I've seen a few old Mannlicher-Schoenauers and Mausers with pits from using corrosive primers. I used a fire-lap procedure to make sure the pits were "smooth," and keep fouling to a minimum. They all shined up nicely, and accuracy was always sub-2 inches.

I agree that the bore-scope is one of the worst inventions of all time. Paying $700 just so you can't sleep at night worrying about your bore. A whore-scope, on the other hand, might be a useful tool.

My borescope opened my eyes to how bad a bore can be and shoot extremely well. It also opened my eyes to how badly machined and full of pits, voids and tooling marks there can be in brand new factory barrels. A bores appearance is not a good indicator of how well it will or will not shoot. There are some beautiful looking bores out there that don't shoot worth a damn, and some that are so rough you wouldn't think there would be any jacket left on a bullet once it has passed through and they shoot good, really good. Ya just never know till you shoot it.

"probably"... but it may still shoot.

can you give a go at the range?

jeffe