How bad does a rifle bore have to be before it won't shoot well?

[opos]

I had several Mosins with sewer pipe bores...really black and gunked up...tried and tried to clean them with little luck..then looked on the Mosin So. Cal site and found that one of the guys had gotten some Smith and Wesson bore cleaning gel (comes in an aerosol can which is wasteful..and in a gel form in a squeeze bottle)...Took the gel and drenched the bore with patches soaked in the gel....took a stainless steel "tornado" brush (the kind that is folded over on itself) and soaked it in gel and began the "process"...put the barrel in a can as it just ran black with gunk...re soaked the bore with gel and let it sit overnight (it will not harm anything...again with the tornado brush and more gel...more gunk every pass...took about 3 days of soak, scrub, patch,etc and the bores came really clean...sharp lands and very little pitting...when done I used lead (not zinc) fishing sinkers and found a .314 bore was pretty common across the rifles....got some .311 and some .313 bullets and found the rifles shot a nice group and the more I shot and cleaned the better things got...I figure I saved some barrels that folks might well have just dumped or not bought and found a great product as well...I use Kano Kroil in much of my hard cleaning...it's great stuff as well.

https://www.cheaperthandirt.com/prod...5511178case.do

[swheeler]

I had several Mosins with sewer pipe bores...really black and gunked up...tried and tried to clean them with little luck..then looked on the Mosin So. Cal site and found that one of the guys had gotten some Smith and Wesson bore cleaning gel (comes in an aerosol can which is wasteful..and in a gel form in a squeeze bottle)...Took the gel and drenched the bore with patches soaked in the gel....took a stainless steel "tornado" brush (the kind that is folded over on itself) and soaked it in gel and began the "process"...put the barrel in a can as it just ran black with gunk...re soaked the bore with gel and let it sit overnight (it will not harm anything...again with the tornado brush and more gel...more gunk every pass...took about 3 days of soak, scrub, patch,etc and the bores came really clean...sharp lands and very little pitting...when done I used lead (not zinc) fishing sinkers and found a .314 bore was pretty common across the rifles....got some .311 and some .313 bullets and found the rifles shot a nice group and the more I shot and cleaned the better things got...I figure I saved some barrels that folks might well have just dumped or not bought and found a great product as well...I use Kano Kroil in much of my hard cleaning...it's great stuff as well.

https://www.cheaperthandirt.com/prod...5511178case.do

I think here lies the answer,cast or jacketed.

[izzyjoe]

I bought an 91 Argentine a few years ago, with a terrible bore. It was a little rusty, but copper fouled bad. I cleaned that rifle for a week, with #9, clp, and some gi bore cleaner, and finally got it somewhat clean, but I never could get it to shoot very good groups. So I wound up trading it off for something else, but now I wish I'd have given it a little more attention, cause I really like it. But if I can buy one cheap enough I'll give it a try, and if they don't work out it makes good trade material.

[Texas by God]

I had two guns that come to mind. A BRNO made K98 and an Astra 1921/400- the bores looked like a black gravel road. With a receiver sight the 8mm would group 2-3" with Portugese FNM ball ammo. The Astra shoots like a target pistol. These two taught me you can't never tell. With that said I would probably think twice before buying unless I could brush out or try before I buy. The US Rifle 1917 is a great rifle and some feel it's the best Mauser interpretation ever. Best, Thomas.

[castalott]

I was wanting to buy a Mosin Nagant 28 but the bore was impossible...Couldn't hardly see rifling.. Cleaning didn't change a thing... The GS had a a range out back and I offered to buy some ball to shoot thru it. With each shot the barrel changed for the better... After 20 shots, the barrel wasn't perfect but amazingly good... A good cleaning then showed a perfectly good( though not perfect) bore...


go figure...

[funnyjim014]

Take off the stock. Make a dummy round to seal the chamber. Fill that sewer pipe full of Kroil oil and let it sit overnight. Scrub and repeat. You will be surprised how may good barrels are filled with gunk and deemed bad. A good indication of copper fowlin is green patches, olt of that can be a pain to remove

[seppos]

In old times the Russians used 10-25% natriumhydroxide solution to clean the rifle bores.. Should not damage the barrel.
Plug the other end and pour the solution in and keep it there over night.
Next day, pour the gunk out and wash the barrel with hot water. After it has dried up, run oil soaked cleaning patches thru the barrel.

S

[6mm win lee]

I got a 1917 from the CMP years ago and it was black as Hilliary Clinton's heart. Scrubed the bejeezus out of the barrel to get most of the crud out of it and then fired a couple of HXP rounds to blow most of the rest. The gun must have been from a Vet organization that did not clean it. The barrel was pitted and looks like heck warmed over but it shoots good. No complaints. It is not match grade but it is tight enough to be minute of groundhog at a hundred yards.

Six

[rosst]

once had the pleasure of sighting in a sporterised No.4 Enfeild for a workmate with the worst bore i have ever seen, there was more pitting than rifling, i kid you not . . ' well this is a complete waste of my time " but man that thing could shoot with the FMJ ammo supplied . . . . for cast i want a brilliant barrel

[Ballistics in Scotland]

There are about as many ways a barrel can be bad, as a human being, and some of them matter much more than others. Simple bore erosion caused by firing is far from the worst. It occurs progressively from the throat, which is the right order, allowing the bore to tighten up on the bullet.

A rifle used for testing cordite, I think the early version with 60% nitroglycerin, is the subject of a detailed gauging record I have in front of me. After 12,000 shots it would admit the .304 pin gauge 4½in. at the muzzle and the .305in. entered 3/16in. At the breech the figures were 19in. and 1⅛in. Even the .309in. gauge entered the bore by ⅜in. more than it did when new.

This is worse erosion than most of us will ever see, let alone inflict. The velocity had fallen by more than 100ft./sec. But the mean deviation on target was 1.45 feet at 500 yards, or a little more than double the dispersion when new. That can't be converted simply to group size, but must be considerably worse than that 3in. at 100 you are looking for. More moderate but easily visible erosion shouldn't be.

Another Lee-Enfield at Woolwich was used to test single based powders, and took a considerably larger number of shots to get into similar condition. With this one it was noticed that accuracy held up pretty well if thin-jacketed, flat based bullets were used, but was much worse with heavily jacketed or boat-tailed ones.

How is cord or rod wear at the muzzle, or excessively energetic removal of atmospheric corrosion, likely to be worse than the above naturally produced version? It is likely to be predominantly on one side.

Pitting is another story, and likely to be less harmful with heavily jacketed bullets, or if you want to use cast, with paper patched ones.

[tazman]

I thank you all for these wonderfully informative replies. This information will seriously help with the purchase I am considering.
This is a great site.
Thanks again
tazman

[Multigunner]

Theres really no telling how a barrel will shoot just by the appearance of the bore, though theres a limit to how bad one can look before I'll even try firing with it.

A total sewer pipe of a Mosin Nagant with barely a trace of rifling grouped like a target rifle when using Hornady .312 bullets, while a near cherry two grove Savage keyholed every shot when using boat tail Mk8 bullets but then grouped consistently sub MOA when using 147gr boat tail bullets pulled from 7.62X54r Soviet ammo and the Hornady .312.

If theres even a trace of rifling left you can find a bullet and load combination that will give useable accuracy, but abadly eroded throat or damaged crown can prevent even strong rifling from doing its job.

I traded off a nice looking Krag carbine long ago without ever firing it after the gapping craters and streamers of Cupro nickel fouling tore the bristles off a bore brush and shredded every patch I tried to put through it.
These days I might try cleaning one like that upp, but wouldn't try firing it unless I aggressively lead lapped the bore to reduce the pitting.

[Ballistics in Scotland]

With that said I would probably think twice before buying unless I could brush out or try before I buy. The US Rifle 1917 is a great rifle and some feel it's the best Mauser interpretation ever. Best, Thomas.

That is easily enough done when someone is selling a rifle, too. It should make us very wary of "should clean up well".

Mechanically the P14 and M1917 Enfields are indeed that good, and the sights were the best on any military rifle for several decades. But it has to be admitted that they are long and heavy. What gunsmiths sometimes do with them, although I disapprove of converting one that isn't already altered or rough, is closer to the intended 1913 .276 cartridge.

[tazman]

Well I found out how bad a barrel can be and still shoot reasonably well. I purchased a Winchester made 1917 Enfield rifle.
When I was looking through the bore at the gun shop, the bore looked reasonably bright and smooth. I could see the rifling no problem.
I took it from the gun shop, directly to the rifle range. I put about 30 rounds through it trying to get it sighted in with no success. It turns out very few of the bullets even hit the target. These were match loads that shoot under .5 at 100 in my other rifle.
When I got home I started cleaning the weapon. This was far and away the dirtiest, most copper fouled rifle I have ever seen. Some one must have coated the bore with toothpaste or something in order to get it to look as good as it did.
I spent several hours Friday and more today trying to get it cleaned out. I finally succeeded this morning. Needless to say the bore was pitted. It has also been rusted. It had tiny pin holes in the bore surface all over the place and was just generally rough.
I decided I might as well try it out and see just how bad I got taken so I took it to the range today with a variety of ammunition.
I started with 150 grain FMJ loads at 25 yards. Not too bad
I moved to 50 yards, still not too bad.
I switched over to 220 grain round nose bullets and there was the key. I started getting 1.5 inch groups dead on point of aim.
I moved to 100 and shot several groups of 3-4 inches with the 220 grain bullets. The 150 grain FMJ averaged about 5 inches at 100yds.
I got out some 168 grain match loads and fired 5 shots at the center of a piece of poster board. I didn't touch it even once. I couldn't believe this.
I moved back to 25 yards to see where the impact point was. Turns out, there wasn't one with the match bullets. The rough barrel was stripping the jackets so badly half the bullets were hitting the target sideways. The others weren't hitting it at all.
I switched back to the 220 bullets and proceeded to shoot the center out of the target so I know the barrel hadn't gotten too dirty or copper fouled.
I didn't realize the match bullets jackets were so thin and fragile that a rough bore would destroy them.
I guess I will stick with the heavy jacketed hunting bullets since those work quite well in this rifle even though I can't believe they do given the pitting in the bore.
It shoots well enough with the 220s that I am satisfied with it's accuracy.
I can always rebarrel it later.

[oscarflytyer]

in 35 yrs and a BUNCH of milsuprs, only ever had one that was trashed. And it was totally gone. I think it was last cpl of inches of bore due to neglect and/or bad cleaning procedures... keyholed jackets at 25 yds and was a wing a prayer and bad bet that a round would find the 18"x18" paper at 50 yds! I recently bought a Savage 340C in 222 Rem that I thought might have the last 1 1/2" of bbl corroded/shot out. Fortunately, after a lot of carbon solvent, pretty little round holes at 100yds - all good.

[dubber123]

Tazman, a little firelapping would likely do wonders. I have an 1894 Swede carbine, one of the little 17" barreled ones, not a M38, that has a dark, fully pitted bore. It has proven hopeless with cast, but after a firelapping shoots full power jacketed loads under 1" at 50 yards.

[Scharfschuetze]

Tazman, a little firelapping would likely do wonders. I have an 1894 Swede carbine, one of the little 17" barreled ones, not a M38, that has a dark, fully pitted bore. It has proven hopeless with cast, but after a firelapping shoots full power jacketed loads under 1" at 50 yards.

I was going to suggest going the same route.

I've used the Wheeler kit for removing tool marks and what not from new barrels. It should smooth out your barrel pretty well and probably cut down on some of the jacket fowling that you are bound to get with that rough barrel. It might even allow you to shoot those match grade bullets out of the rifle.

[kawasakifreak77]

They can be pretty bad & still shoot.I gotta regular ole 91/30 mosin that is nicknamed "the sewer pipe" & for a good reason. Its bore is so rough you can't patch it. It'll just rip up the patch going down the bore. Crazy thing will shoot a consistant 2 moa with yugo heavy ball. Its the darndest thing...Flip side to that is, I just bought a K31 with a mirror bore that will barely hold 4 moa. My other two will easily do 1.5 moa with GP11 & one will do sub moa with my handloads.Never know 'til ya shoot it man.

[JWFilips]

Well I have a J.P. Sauer Und Shon 98 Mauser Bore was trash Throat was out to .330"
Here is the bore and here are the best target I have shot with a downed sized NOE 340 Bullet


I find with a worn bore; a long boolit which is sized .002" to .003" larger seems to bring them back to life

[bouncer50]

Funny thing some of the worst bore can shoot better then a good bore. I have two a 98 Mauser and M1 Grand that have Salt & Pepper bores and they shoot great.