Fire Lap Dark Bore?

[Themoose]

Just spent a good portion of three days scrubbing the bore of a 98 Krag...removed a whole lot of crud in the grooves, but they remain dark after my patches comeout clean... I would like to shoot cast bullets in my new addition and want to clean and smooth up the barrel as much as possible... I have fire lapped a few new rifles, but never a veteran with dark and rough grooves... will firelapping help or hurt? I know to check frequently when doing this to prevent removing too much material from the rifling.... anyone have some experience or tips they could share with an old geezer?

Thanks in advance for your help,

TheMoose

[Mk42gunner]

I've never fire lapped anything, so I can't tell you yes or no. What I would do before taking that step is to buy a bottle of whatever foaming cleaner is locally available and try it.

I was amazed at how much nasty stuff came out of the barrel of my favorite little No. 2 Remington Rolling Block the first time I used it. Mine is Hoppe's Elite that I bought at Walmart.

The bore on that rifle isn't dark, but it looks rough. I am beginning to think it is severely impressed leading, since it came to me with a partial box of Navy Arms made in Brazil .32 Long ammo, (which is worthless by the way).

Robert

[.22-10-45]

I fire-lapped an 1898 Krag with dark grooves. Used the NECO kit when they came out in the early 1990's. best accuracy was 1 1/2" at 50yds. After lapping, grooves shiney and bore has about .0001" taper from breech to muzzle slug miking at .3105" 100yd. groups are around 1" now.

[Themoose]

Thanks..I hope I can do as well. I used foaming cleaner , Hoppe's, Eliminator, and soaked in Kroil for two nights to get clean. Thought the lapping would help. I have LBT lap kit... guess it's time to see what it can do.Thanks again guys for your help.

[country gent]

A milder version of fire lapping is to obtain some bore dia bullets and paper patch them up to groove dia or a .001-.002 over groove dia and fire them Clean between shots. Paper is mildly abrasive by it self and can polish with out removing alot of material. It might do just what you want there

[Multigunner]

I'd try to find a smith who can lead lapp the bore. You can try lead lapping it yourself for that matter instructions should be available online.
Lead lapping should preserve the basic profile of the rifling and avoid undue wear of the throat and leade. Fire lapping seems to work fine for most, but I suspect that lead lapping would be better for the older more worn and pitted bores.

Also be sure that all Cupro-Nickel fouling has been removed chemically or electronically before trying any sort of lapping, otherwise the results may be uneven. Most modern over the counter solvents have little or no effect on cupro-nickel fouling.

[gnoahhh]

If you are desperate to remove cupro-nickel fouling, one sure way is to use ammonia- the real McCoy, the stuff that is called "stronger ammonia". It's how the old timers did it. Plug the chamber, fill it to the brim, and plug the muzzle end. Let sit for 1/2 hour and dump it out, flush well, dry and oil. If you do this, for god's sake do it outside and wear a respirator. If you get a whiff of it, it will knock you out. Ask me how I know. (But that's a story for later around the campfire.)

[shredder]

The thing with fire lapping is that it only works on the throat. Fire lapping can also move the throat forward in a hurry so be very careful with your lapping grit size. 220 will take off enough metal that you may be shocked if you have a borescope.

[Skipper]

Moose, this might be the best solution:
http://estore.thecmp.org/store/catalog/catalog.aspx?pg=product&ID=065CRI/3040R&item=&sfv=&cat=BAR&desc=&udc=&mct=&vndr=&ba=&pmin=&pmax=&note1=&note2=&note3=&note4=&note5=&max=

Have you considered a rebore?

[screwcutter]

Fire lap as a last resort, heed the cautions about throat wear, I've never done one yet.

Have seen a buddy move throat out real quick, fortunately he realized what was going on

before he went too far. I would spend another 2 weeks, make that 3 soaking for 2 or 3

days at a time with Wipeout and see what comes out. Had a 1 303 that looked clean

another that looked bad that took that treatment and came out looking good. Then shoot a

couple hundred cast boolits, or as suggested some paper-patched boolits and see how it

looks.
mr

[Frank46]

Have a 95 winchester SRC in 30-40 krag. Metal fouling was so bad you could actually see lumps on top of the lands. Took a long time even with Butch's Boreshine to get it out. Same with a BSA 22rf martini leading originally led me to believe barrel was in bad shape. Clean and scrub then clean some more. Let soak with a good solvent and repeat. Finally got the lead out though. Same with a 98 krag that was cut down, swore the more I cleaned it the deeper the grooves got. Frank

[Outpost75]

I have a Finn M28/30 Tikka Civil Guards rifle which has a "dark but strong" bore. I did not fire lap, but decoppered with Shooter's Choice copper remover and then scrubbed with Brobst JB paste and Kroil. Shot for group with cast NOE 314299 without GC, 11 grs. of #2400 and cleaned every ten rounds with Kroil and JB. After 100 rounds and ten cleanings, it was sub-moa with cast! So, shot with Sierra. 311 diameter 174 grain Matchkings and 44 grs. of RL15 and averaged under 2 inches for ten, 5-shot groups iat 200 yards using 3x Russian PE scope and reworked mount off PK machinegun. Done!

[Bent Ramrod]

Roll your raw castings (.311 size as cast) between two strips of steel with a puddle of Clover 320 Compound on the bottom strip. Put the treated boolits in a plastic tray from a pistol ammo box.

Take one shell to the range, depriming/repriming setup, primers, powder and powder scoop, long tweezers and a small dowel. Take a box of the best shooting cast boolit ammo you have developed for the rifle so far.

Load the one shell over and over. It will get impregnated with lapping compound, and you throw it away after the lapping job is done. Put a boolit into the breech with the tweezers and push it into the leade until it stops. Put the loaded shell in afterwards. The powder charge should be a light loading of Unique or some such, just enough for 25 or 50 yards.

Fire five shots of this, then clean the bore with a Hoppe's soaked patch, then a good scrub with a Hoppe's soaked bronze brush, then more patches. Make sure you wipe down the moving parts of the gun too, to make sure no stray abrasive has migrated around. You should notice your barrel getting warmer than the powder charge would indicate. There's a lot of friction generated in those lapping rounds.

Keep doing this: five abrasive rounds, then clean thoroughly, and five more. I do this off a bench rest, firing at a target at 50 yards, just to see what is happening. After about 40-50 shots, I usually get curious enough to clean thoroughly, fire five cast boolit rounds of my best loading to see if any improvements have shown up. Five of your regular loads will noticeably heat the barrel up, indicating that some of the Clover is still in the steel, being picked up by the boolits. After ten shots, typically the barrel is only normally warm from shooting, indicating you've scoured the Clover out of the bore. If the accuracy doesn't satisfy me, I clean up and plan to come back again with another round of abrasive boolits.

Generally, with a scabby bore, there is some improvement after one of these runs, and then comes the question of how long one wants to keep the lapping up. Will it keep improving? Will more degrade accuracy back to worse than before? Where is the cutoff point? There, your "gut" has to be consulted and followed. Remember, you can always come back for another lapping session if it isn't quite good enough. Once in a while, it doesn't work. I had a .32-40 Winchester barrel with good dark rifling that no amount of fire lapping would help. Turned out it had a blunderbuss muzzle from too much sloppy cleaning rod technique.

Not to put too fine a point on it, this doesn't add up to a relaxing morning at the range. But it is shooting, rather than pushing and dragging a lap through the bore in a hot, dusty garage or shop. I've never spoiled a barrel doing this, and sometimes the accuracy has been significantly improved. I've done this with pitted bores and with reline/rechamber jobs that for some reason aren't shooting up to snuff. I have never tried to lap (fire or hand) a new barrel before firing it, or a new blank before fitting it to a gun. There is no sense in that whatsoever.

Cleaning with a brush every five shots is a must. There is no lube on the boolits, except for the grease in the Clover Compound. You will get leading, and it will happen at just those places that are the roughest and most in need of lapping. A layer of lead will protect the surface underneath and you will just wear the good areas without fixing the bad ones. Keep cleaning, and stay aware of what you are doing. The process doesn't "do" itself. I think these people who say fire lapping ruins bores have had way too much fun banging a bunch of fire-lap loads downrange. That's not how it works.

[JHeath]

Knowledgeable guys swear by the electronic fouling removers like Outer's Foul-Out. Haven't used one yet. But I wouldn't touch the bore until I tried that. Supposedly it removes all the fouling so completely that you really know what you have. Layers of metal and powder fouling can be almost impossible to remove by ordinary means.

[JSnover]

What screwcutter said. Lapping and firelapping are great if you've already tried everything else.
Ammonia will get the copper out but DON'T leave it in too long or it will attack the steel.
When you're sure the bore is clean, shoot it. If you think it can do better try the paper patch.

[bdicki]

I have a Finn M28/30 Tikka Civil Guards rifle which has a "dark but strong" bore. I did not fire lap, but decoppered with Shooter's Choice copper remover and then scrubbed with Brobst JB paste and Kroil. Shot for group with cast NOE 314299 without GC, 11 grs. of #2400 and cleaned every ten rounds with Kroil and JB. After 100 rounds and ten cleanings, it was sub-moa with cast! So, shot with Sierra. 311 diameter 174 grain Matchkings and 44 grs. of RL15 and averaged under 2 inches for ten, 5-shot groups iat 200 yards using 3x Russian PE scope and reworked mount off PK machinegun. Done!
^^^^^^ This

[aap2]

All of the above advice is good. I have always tried to buy guns (mostly old ones) with "mint" shiny bores assuming that the dark and slightly rough bores would not shoot well or lead badly....This isn't always true especially with boolits and the reduced loads that we often shoot. I have several rifles with "dark and slightly rough" bores that shoot just fine after an initial cleaning to remove the crud. They are about as accurate as a nice shiny bore and don't lead with boolits. I have never lapped anything but my 2 cents worth would be: clean the bore the best that you can and shoot it before doing anything aggressive. You might be surprised ay how well it shoots.

[Themoose]

Thanks for all the advice fellows... I am holding off on doing anything right now...I got to the range for the first time with the newly acquired rifle... it has been sporterized and with the sights provided, shot about 18" high at 25 yards with jacketed factory ammo.. A friend was there with his original Krag carbine and had me try a few of his cast 200 grain loads that shoot well in his rifle... I shot them @ 50 yds and they shot a perfect keyhole...... will take the rifle back to the bench, clean thoroughly, oil bore and slug the barrel and do a pound cast of the chamber and throat...(just got my LBT throat slugs in the mail yesterday)...nothing good comes easy.... this is just a slight bump in the road...not worth getting impatient at this point... sorry for the ramble... I figure if I write this last part down, I will begin to believe it.. and slow down and take it a step at a time...sooner or later it will come together..... thanks again

[Char-Gar]

Use one of the foam cleaners like Wipe-Out. It will take four or five applications to clean an old rifle down to the steel. When the patches come out clean, the barrel is clean.

A clean rifle with a dark bore likely has some fine micro pits from a previous life with corrosive ammo. These pits break up the light reflection. It is no big deal if the rifling is still strong. Just shoot it, in time those little pits will fill up with lead and lube and the barrel will look more shiny if that make a difference, which it does not to me.

These old darker bores most often will shoot cast bullets as well and the new shiny ones.

Now here is the "take away": Stop worrying about problems that most likely don't exist. Shoot the rifle and let the target be your teacher.

Addendum: I reread your original post and saw that your rifle was a Krag, a rifle with which I have some familiarity. The problem with your friends Krag and the keyhole bullets was the bullets were to small. Krag barrel groove dimensions vary quite a bit. Regardless of bore groove diameter, Krags have a large throat. Just size your bullets .312 or .313 if the rounds will chamber easily with a bullets that size and your targets and life will be good.

The last Krag rifle left Springfield Arsenal 113 years ago. Expect a very large quantity of difficult to remove metal fouling. The Wipe-Out really does speed up the job significantly.

[Themoose]

Thanks again to all. Last night and this morning I did more cleaning and did a pound cast of the throat and slugged the bore...not a perfect job, but it looks like the throat is .313-.314 and the bore .311.... only faint grooves seen on barrel slug... will keep on cleaning and try larger bullets... thanks again for everyone's input.

[Outpost75]

A throat of .313-.314 and barrel groove diameter of .311 with bore about .302-.303 is fairly typical.

You want a cast bullet in which the forepart or bore-riding portion is large enough to be lightly engraved by the tops of the lands.

You can test this by poking the nose of a bullet into the muzzle. If the barrel has NOT been "counterbored" the rifling should be intact all the way to the muzzle crown, so if you can feel resistance and see marking on the nose of the bullet when withdrawn, that is just right. If the bullet cannot be pushed into the barrel with hand pressure, but dummy rounds chamber and extract without de-bulleting, this does no harm. The bullet nose may be lightly engraved as long as it is not shoved back more deeply into the case.

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If the bullet nose enters easily all the way to the first driving band, this means that the forepart is too small and that the forepart of the bullet will not be supported by the lands. This causes the nose to "slump" or bend during in-bore acceleration and accuracy goes right out the window.

From the dimensions you gave, Swede Nelson's version of #314299 from NOE will be a PERFECT fit. You need look no farther. In my 7.62x54R rifles for a light gallery load I use the bullet as-cast and unsized from wheelweights, tumbled in Lee Liquid Alox or LSStuff 45-45-10 with either 7 grains of Bullseye or 11 grains of #2400.

For 100 yard target shooting use a gascheck and increase the load to either 8.5 grains of Bullseye, 16 grains of #2400, 22 grains of 4198, 24 grains of RL7, or 26 grains of 4895, 4064, RL15 or Varget.

For 200-300 yard target shooting increase the alloy hardness to 15 BHN using a 50-50 mix of wheelweights and linotype, then load 30 grains of RL7 or 3031, or 30-35 grains of 4895, 4064, RL15 or Varget, as accuracy indicates. These charges also make good hunting loads.

In a sound Krag these loads will be safe, but should not be exceeded.

[Char-Gar]

Thanks again to all. Last night and this morning I did more cleaning and did a pound cast of the throat and slugged the bore...not a perfect job, but it looks like the throat is .313-.314 and the bore .311.... only faint grooves seen on barrel slug... will keep on cleaning and try larger bullets... thanks again for everyone's input.

Krags were the first small bore smokeless round the Springfield Arsenal made and they had a learning curve. There were acustomed to loosey goosey lands and groove specs in the barrels, depending on black powder and a soft lead bullet to expand to fill the grooves.

Townsend Whelen write in "Days of the Krag" that the first one that fell into Army hands had a wide variety of barrel dimensions. He said some of them went as high as .316 in the grooves. I have never seen one that big, but do have a four digit SN Krag with .3125 grooves. It shoots very well with .313 bullets for the big throat.

Early Krags ran from .3095 to .3125 in the grooves, at least the ones I have measured. These Krags turned lousy accuracy with the smokless jacketed rounds with .308 bullets, so Springfield called in Harry Pope to figure out what was the problem, as they wanted rifles for Palma Match competition and the Krags just were not cutting it. Harry almost had a stroke about the loosey goosey barrel specs and they corrected that. Later Krags came out spot on .308 in the grooves. That did the trick.

Cast bullets are just the ticket for these larger bore Krags. As you found out .313 to .314 throats are pretty standard, a few have been found as large as .315. You should use cast bullets as large as you can that will still chamber easily. For me that means .313 bullets, but with of my Krags I have to neck turn the brass to be able to use bullets this size and still have room for the neck to expand a smidge and turn loose of the bullet upon firing. The improvement in accuracy has been well worth the effort to neck turn some cases.

If after all the handloading magic if you are not getting the accuracy you want, look to the fit of the action in the stock as the culprit. Krags have no receiver lug to prevent the action from moving back in the stock upon firing, but depend on the back of the magazine box bearing on the wood to do that. A firm fit there is essential to accuracy. If there is a space there, a shim or some glas beding compound will cure that.

The NOI bullets that Outpost suggest is a top notch bullet for the Krag. I use another just because I have several of them and they are sterling Krag bullets. I use 311407 Mod also made by Swede at NOE. It is lighter at 165 grains and is a modification of the Loverin design having an as cast body of .314 and the top two bands .302 -.303 to grab and ride the lands.

[LAGS]

I have made Bore Laps for several rifles by using worn out Bore Brush an JB Weld.
It worked well and I was able to lap out most of the Frosting in old Mil surp Barrels with out distroying the rifling totally.
I lapped them with the Epoxy Lap, and SemiChrome polish or Flitz Polish.
Just clean the bore really good, coat the bore with Johnsons paste Wax, then plug the barrel with a patch.
Coat the old bore Brush very Liberally with the JB Weld, and insert it in the bore down to the plug on a cleaning rod.
Most of the time you can when hardened, Pull the plug out, but somtimes you have to drive it out from the chamber end with a Brass rod.
It doesnt remove the Pitting, but it does polish over the top edges of the pits, so the bore is smoother.
If you have ever seen rust on metal, it swells up where it is eating the metal.
Without the really sharp edges on the pits, your barrel will work "Better", even if it is not Perfect

[historicfirearms]

Char Gar's post is spot on as usual. Go shoot it and see how it does before firelapping. My old Krag had a dark bore and pitting in the grooves but it was a great shooter. Don't let a little pitting bother you.

[Themoose]

I am not planning on firelapping the bore... I have put in another $12 for Outer's foaming bore cleaner(can't find Foul Out)... picked up a couple thousand patches and a half dozen bronze brushes at Gettysburg gunshow yesterday... spent another six-eight hours yesterday scrubbing with the foaming cleaner, terminator and even filled the bore to soak with ammonia for 30 minutes.... still getting out brown patches after brushing... thinking it is perhaps rust from pitting in grooves. The lands are mirror bright....While at the gunshow yesterday I did pickup a Bubba'd 1898 Krag and beside missing an extractor spring and having the rear sight screws filed off flush with the barrel.....found what appears to me as an almost pristine bore after two cleanings with the foaming bore cleaner....I sold an old project rifle on the way into the show, complete with an extra barrel and walked out with a new(to me) project rifle with $1 left over... who knows, this may have been a reward for all the work I'm putting into the dark bore.... what I am looking forward to is shooting the two rifles side by side and seeing how they group... can't get much better than that... Happy Memorial Day to all and especially our men in uniform, their families, my fellow veterans and their families.... time to thank those who gave everything for their country and brothers in arms...

[Mk42gunner]

Sounds like you labor is bearing results. Keep at it.

The first thing I thought of when I read "brown patches" was you are finally getting down to some of the rust, and are starting to get it out.

Robert