22 rimfire lapping kit

I wrote a very detailed article on fire-lapping a .22 barrel for Precision Shooting years ago, and included "before" and "after"

accuracy testing from a benchrest set up in a 50 meter indoor range.  I also included photos of  the bore "Before and After" taken using a Hawkeye bore scope.  I fire-lapped  using the Tubb "Final Finish" fire-lapping kit for .22's exactly according to his directions. He instructs users to fire all cartridges in the kit working from coarse to fine grit, He makes no provision for assessing progress during the firing sequence.  Then clean the rifle thoroughly, and you're done. 

I wrote the article to help readers who hear from shooting buddies about casual fire lapping "helping" rifles, but who don't get the benefit of detailed, carefully-quantified accuracy testing before/after, or the ability to actually SEE the effect of fire-lapping due to the relative expense/rarity of bore scopes, although they are now becoming more available.

The rifle I chosse was a Browning copy of the Winchester 52 sporter that gave lackluster accuracy.  It did have a chamber that engraved the bullets into the lands, in match-rifle style.  When I started, the origin of the lands was sharp with little wear.  Afterwards, the land origins were severely worn down, looking like a sand dune that has been washed out to sea due to a high tide.  Areas of micro-pitting in the barrel were smoothed out to bright, smooth metal.  A couple of areas of cleaning rod damage (I bought the rifle used) showed that the damaged areas were smoothed out but not eliminated.  Overall, the rifle shot worse after lapping than it had before.  The Tubb kit process put a **huge** amount of "wear" on the throat in short order.  The barrel was ruined, but wasn't a grievous loss.  Before lapping,  it was a 0.5" average (5 rds) shooter at 50 yards, with ONE type of ammo ONLY.  (SK-Jagd High Velocity Hollowpoint.)    It would not group this well with several excellent lots of Eley Tenex or other match ammo, or  high quality US-made HV  hunting or standard velocity ammo.  Obviously, I would not use such a kit "blind" on a rifle that already shot well!

If I were to do any fire-lapping, I would only use the finest grits, and I would only do it if I could clean frequently (every 5 rds) and check my progress with the Hawkeye Bore Scope.  By being able to check out your barrel beforehand, and approachthe needs of THAT particular barrel with a planned strategy of grits to use, you might be able to improve somewhat.  However, without a Hawkeye or other good borescope, I would be very leery of doing any more than just a few rounds of fine polishing compound in hopes of smoothing the barrel if needed.

Much folklore, superstition and misinformation about cleaning rimfires abounds, chiefly erring in the direction of NOT cleaningthe barrel.   Not cleaning it will shorten its life significantly, both through wear-related erosion and corrosion.   Without going into long detail, I've made a serious study of cleaning practices for accurate rimfire barrel maintenance, and believe they should be cleaned after every shooting session.  (More on this below.)   Using a good rod/brush/solvent/patches will prevent the next session's bullets from having to plow their way through/over  hardened fouling with primer grit encrusted into it, which wears away at the barrel. 

I've consulted many REAL experts in the field; one example is an Olympic Gold Medalist who won Olympic Gold with a rifle with over 170,000 rounds through it!  He only retired the rifle from competition after about 230,000 rounds because while it remained accurate, it became more and more picky about which lots of match ammo it would shoot really well.  Throughout the barrel's life, he religiously cleaned the rifle as above, as per the barrelmaker's instructions.  He usually cleaned it at intervals of no more than about 130 rounds, IIRC, to maintain peak accuracy at all times.

Everyone's accuracy frame of reference and needs are different.  I come from a competitive Smallbore Rifle Silhouette background; for reference, 5-shot groups that average 0.5" at 50 yards is about the worst accuracy I can tolerate, and my match rifle averages well under 1" at 100 yards with good ammo in calm conditions. So, that's my frame of reference.  Of interest, Ruger 10/22 sporters have long had a mediocre to actively bad reputation for accuracy using the factory barrels.  I recently borescoped 3 Ruger 10/22 stainless-barreled sporters, and the internal finish was excellent!!!   Very smooth, no tool marks, etc.  Properly cut, sharp crowns and the chambers looked well cut and concentric (as far as eyeballing goes.) I have heard from the owner of one of the rifles, and he is very well pleased with the accuracy of his rifle using lower-tier match ammo at 50 yards, for an accurate small game rifle.  With any luck, maybe your liner won't need any smoothing.

With a freshly-cut chamber, there may be a few sharp edges remaining from chambering.  You might consider firing 1-5 shots and then cleaning with a good, straight, one-piece rod and brass or bronze core, brass bristle brushes and solvent, several times as you sight the rifle in, begin testing, etc.   This gives a chance to knock off some sharp edges that might accumulate lead fouling if left unattended.  Also, I would not expect the rifle to give its' peak accuracy until after it's had about 200 rounds through it.

FWIW, I did a test of a new Hoppes Bore Snake in a new Anschutz barrel, checking with the Hawkeye.  With 300 rounds of fouling from match ammo, the bore was a uniform grey from powder/lube fouling, with just a couple of small bits of lead accumulatedat the throat.  1 pass with the Bore Snake, using solvent, got all the powder and lube fouling out of the barrel, but didn't touch the leading.  9 more passes with the Bore Snake had no further benefits.   (So, I consider them  good for quick maintenance, but not a substitute for actual cleaning with a rod, brush, patches and solvent.)

Next, I tried 1 cleaning rod stroke with a patch and solvent, followed by one dry patch, and checked with the borescope.   About 1/3 of the (very small amount) of leading was gone.  I then added 1 stroke with a solvent-wet brush, back and forth.  I then ran 1 dry patch through the bore,checked  and all the leading was gone!   So, my cleaning regimen involves just a couple of strokes, ending with a wet patch and dry patch to leave a little solvent in the bore to protect it.  No need for lengthy cleaning rod sessions, which lowers the chance of doing any damage with the cleaning rod and shortens cleaning dramatically, with evidence-based, proven-superb results.   Naturally, should the internal condition of the bore change and require more cleaning, periodic checks with the Hawkeye will let me adjust accordingly.

Finally, I have improved the accuracy of several barrels (both rimfire and centerfire) as follows:  Take a work bronze brush, and pack "Flitz" creme polish into it, between the bristles.  Then put a thick-ish coat of Flitz on a cotton patch and roll it around the brush.  I start with a corner of the square patch in the center of the brush and roll it around, sticking the end down with loose Flitz as needed.  This gives a tapered "mop" that fits tightly into the bore, but doesn't resist cleaning too hard.  After about 10 strokes back and forth with the Flitz patch in even a clean barrel, examining it will probably show it to look quite black.  I believe part of that is due to the breakdown of the Flitz itself, not just fouling.  I do this several times at a session, starting with a clean barrel.  Depending on how your barrel is, you might need more or less sessions like this, but sometimes the accuracy improvements have been dramatic, and I  have not seen any damage occur from this method.

I hope this helps as you consider your options for your new barrel!

Sincerely,

John