barrel polishing / lapping

[The other DWS]

Assuming that the some rifle barrels have a reputation for being a bit rough I can see that that alone might contribute to cutting the patch on the land tops. Polishing my barrel has been suggested, as has just "shooting it in"   Lapping and/or polishing should not be a big problem,  several methods come readily to mind.

 However, has anyone ever applied the "fire lapping" method to M/L rifles? 
Typically the "fire-lapping kits" consist of 5 or 6 pure lead bullets in each grade with the grit mechanically rolled into their surfaces to be fired at low velocity.  I'm wondering about the practicality of firing a series of graduated lapping and and polishing grit impregnated patches through the bore--with thorough cleaning between abrasive grades.  It is used, but somewhat controversial, with cartridge rifles since it can cause excess erosion in the critical throat area.  However since the barrel I'm using has round bottom rifling already, and we are not shooting bare projectiles

[northmn]

Might work.  The original lapping was done with a threaded rod and bore guide.  A pure lead slug was drilled and placed between two nuts for tightening and expansion and impregnated with a abrasive compound and ran through a barrel until any tight spots were removed.  Commonly a new barrel like you have may often be steel wooled or otherwise poslihed to remove machining burrs that may cut patches.  Try something simple before you go to the more complicated.  Many barrel shoot in after 50 to 100 shots.  I used to have to thicken patches about midseason in the old Numrich barrels as they would do so.  Working buffing compound into patches for the first shots may speed up the process.  If the rifle shoots OK with slightly damaged patches so what?

DP

[roundball]

Not an authority on this subject at all...but I haven't ever tried fire lapping as I'd be worried about possibly doing more harm than good.
Over the years I've had a couple of barrels that cut patches when they were new, but settled down after a few range trips, and frankly, came to believe it was a case of the "ends" of the lands at the muzzle being sharp, not the lands down bore themselves...as the ends of the lands at the muzzle got polished from short starting a 150-200 PRBs, the patch cuts went away.

[Dphariss]

I would try a tight fitting "patch" of 0000 steel wool first. 20 strokes or so should deburr it.
OR try a dry patch over the powder then the patched ball.

Dan

[Don Getz]

I've discussed using this many times before.    Use some scotchbrite, works better than steel wool, and is easier to use.
Cut a piece of scotchbrite about 2" x 3", tape the 3" edge to a small ramrod, steel, brass, whatever you use for cleaning the gun.   Wrap the scotchbrite tightly around the rod, then trim with a scissors until it will go tightly into the bore, then
run it up and down the barrel about 100 times.  It will take that sharp edge off the lands and will polish the bore, but will
not remove steel.    I've found that it is much easier to use this than steel wool, and won't leave any of those fine steel
particles in the bore................Don

[roundball]

Use some scotchbrite, works better than steel wool, and is easier to use.

Makes perfect sense...especially coming from a well reknown barrel man !
 

[BrownBear]

There's been lots of discussion/debate over the years, and you'll find a bunch if you google it.  This is the technique I've tried a couple of times.  I'm a little leery of going too far and probably didn't push it far enough, but I didn't see all that much difference.  I've come to rely on lots of shooting, rather than using even Scotchbrite pads.  It can take 100-200 shots, but I need the practice anyway.

It's worth pointing out that the crowns on lots of rifles are awfully sharp and contribute to patch cutting and accuracy problems until you deal with it.  I've found the best solution is coning.

[The other DWS]

"much ado about nothing" eh?
 I guess if it ain't really broke I don't need to fix it.  For the 1st 5 experimental shots I was pretty happy with accuracy.  I don't know enough about patching rifled barrels to know whats right or wrong.  The short starting did take a bit more effort than I expected.  maybe just a bit polishing on the entry ends of the rifling might help?

[Dphariss]

There's been lots of discussion/debate over the years, and you'll find a bunch if you google it.  This is the technique I've tried a couple of times.  I'm a little leery of going too far and probably didn't push it far enough, but I didn't see all that much difference.  I've come to rely on lots of shooting, rather than using even Scotchbrite pads.  It can take 100-200 shots, but I need the practice anyway.

It's worth pointing out that the crowns on lots of rifles are awfully sharp and contribute to patch cutting and accuracy problems until you deal with it.  I've found the best solution is coning.

Shooting works as well. Scotchbrite or steel wool is nit going to damage a bore unless you spend a lot more time on it than I have energy for.
I recently obtained a pistol with a neglected bore, micro pit. I used 120 silicone carbide powder on a tight patch about 10-20 strokes. Not a cure but it helped a great deal looks good with a bore scope and should shoot fine. Will likely cast a slug in it and lap the thing to clean the grooves. Its one of a signed pair that are reunited again.
Steel wool predates scotch bright and old habits are hard to break 

Dan

[The other DWS]

With my little finger tip I could feel sharp edges and burrs right at the muzzle edge of the rifling.  I suspect that the muzzle crowning was not followed up carefully with a good polishing.  I used a very fine polishing grit impregnated tapered dense gray felt dremel-type "bit"  it was slightly larger than bore diameter at the shank end and slightly smaller at the lead end  (just wish I could remember where I got it) Using a low battery powered variable speed drill at low and slow I very lightly polished the crown and the lead edge of the rifling.  its silky smooth now and mirror shiny.
I just did a real careful thorough barrel clean using some puffy round make up removal pads left behind by an ex-wife.  They make a real tight fit in a 54 bore.  They have a lot of loose fibres and catch and drag real easily.  Working them up and done the bore slowly and carefully I felt no catching or dragging, no variations in pressure working the rod either way so I don't think I have any major bore problems--so far.

[Daryl]

If you're in a hurry, fire lap it, just make certain the crown isn't the reason they're cutting on the tops of the lands instead of it being a rough bore.  I've not seen any of the newer barrels as being anything near what I'd call rough.
I have a couple barrels that are what I'd call rough, but neither has ever cut patches with "heavy" material and .005" under balls. (heavy means .025" denim)
One of them, the Kodiak, will burn the .022" denim patch with a small ball, the .562", with over 100gr. of powder, but they aren't cut and a thicker patch is needed for heavier loads, due to the pressure.


Brand new barrels can have sharp land corners, that need smoothing. fire lapping can eliminate that in just a few rounds, or so will scothbrite or steel wool.


I've never tried firelapping a muzzleloader, but find myself wanting to try it at least once.  I've firelapped a number of modern rifles, large bore and small and always obtained postive results, even in a .17 cal. high speed number that merely used JB for firelapping to get rid of a 'spot' just ahead of the chamber.

[blackdog]

JB bore cleaning and Bore bright work great for polishing barrels and great for cleaning.  Brownells sells it and a small can will last many years.  I've seen both centerfire and ml barrels that wouldnt shoot consistant cleaned and polished with it and shoot like new, if not better.  I use it on all new barrels because there is no break in period after use.

[The other DWS]

Took it back out today along with the M/L Schuetzen and a few non-BP .22 rf schuetzens to tune up for the upcoming match this weekend.   also took my nephew and a buddy of his who have never done any M/L shooting.  we all had a great time and they got an intro to both flintlock and percussion M/L----they enjoyed the flinter the most.  Then I turned them loose with a couple martini 22rf target rifles while I was doing my thing.
   I was doing all my shooting offhand at 100 yards today since I was in tune-up mode ( definitely need more of it before friday)  I'll do more precise bench work later on.

Anyway, the little bit of muzzle deburring and polishing I did worked wonders--- no more cut patches.  10 shots at 100 gave me a pleasing group--to me at least,  about 1 1/2 wide and 8 long.  It was about 6 inches right of my point of aim, but there was a pretty stiff left to right wind. Better wind conditions and a bit of sight adjustment will take care of the worst of that.

 I think that more precision in pouring the main charge will reduce the vertical dispersion a lot  but then I tend to get more vertical than horizontal spread when shooting off hand anyway in the schuetzen matches--so I was not too surprized'

[Daryl]

Wind can be a booger - but then, so does differing light on that front sight. Lots of elevation comes from that.  Poorer eye sight also gives elevation problems due to indistinct front sight height.

[The other DWS]

"Poorer eye sight also gives elevation problems due to indistinct front sight height"    and how,  if my eyes were any worse,  I'd need a seeing-eye to do my aiming--a real gun-dog.  I need to get a re-check of my bifocal RX in my right/sighting eye ASAP.  The current rx is only 6 months old but the right eye has shifted--for the worse. 
However the aperture rear /pinhead front sights on the schuetzen M/L and the scopes on the cah-tridge single shots worked ok.   I may just need to square up the back surface of the flinter's front sight---kind of hate to--it makes it look pretty modern----but form follows function I guess

[Daryl]

The pin-head front is more useful than a blade, that's for sure, when the eyes get 'weak'.

[The other DWS]

particularly if it is inside a hood.  aperture,  hood, round red target bull, ark silhouetted pinhead---oh yeah!!! circles inside of circles inside of circles is a good thing for aging eyes

[Daryl]

I'm getting dizzy already.

[J.D.]

Sounds like you have the problem solved. However, I would like to share my experience with scotchbrite pads and fire lapping, for future reference.

I have fire lapped a coupla ML barrels, and it ain't quick. The bore needs to be thoroughly cleaned between shots, to include removing any potential lead smears. IMHO, any remaining residue will prevent the grit from working in that area, so it's all gotta come out. Every bit of it, and that takes time.

IMHO, fire lapping using a patched ball will only work the tops, corners, and probably some of the side of the lands, but probably won't get down into the bottoms of the grooves unless one uses an incredibly tight patch/ball combination. So a tight fitting lead slug, I used hollow base minis that were a couple of thousandths smaller than bore dia, charged with grit while rolled between two polished steel plates, must be used.

Fire lapping did work, well enough, but, IMHO,  compared to lapping with a cast lead slug on a threaded rod, fire lapping is slower and more trouble.

Don's advise to use a scotchbrite pad to remove sharp edges from the lands is dead on. The problem I have had with steel wool is holding the steel wool secure enough to do its job while getting a tight enough fit to the bore.

An 1 1/2-2", or so, square of green scotchbrite pad on a jag, one size smaller than the bore of the barrel you are working, will hold tight and do its job,rather quickly.

God bless

[Dphariss]

JB bore cleaning and Bore bright work great for polishing barrels and great for cleaning.  Brownells sells it and a small can will last many years.  I've seen both centerfire and ml barrels that wouldnt shoot consistant cleaned and polished with it and shoot like new, if not better.  I use it on all new barrels because there is no break in period after use.

A lot on caustic blued barrels have a lot of rust (bluing) in the barrels and JBs works pretty well fro removing or reducing this.

Dam

[Wyoming Mike]

I have fire lapped barrels.  Usually it is the final cleanup on a neglected barrel.  After the Scotch Brite and steel wool treatment, I will shoot four or five balls through the barrel with jewelers rouge for lube on the patches.

Most barrels that have been pitted trough neglect will still shoot well enough when they are cleaned up but crud up fast.  The fire lapping seems to help with the barrel crudding up so fast.

I have never done it on a new barrel but know other people who have had good luck taking the sharp edges off.

[The other DWS]

I imagine that is usually why a barrel would be "freshed out"  since the patched lead would do very little harm to a bore---if any at all.  It pretty much had to be the corrosive products of the BP fouling combined with a casual approach to cleaning that created a need for a light re-boring to clean up pitting.