Shining The Sausage ..

 Over the years I have read articles about BORE LAPPING and 'Fire Lapping' .. I never have felt the need to indulge - but I'd guess that if you own a gun that has poorly machined rifling or bore surfaces and you decide that it's performance is below par ... you might be tempted to have a go at improving the internals - or to pass the firearm to your friendly local Gun-Smith for the Professional to expertly transform your "dog" into a golden unicorn. 

The lapping process involves casting a lead slug from the bore and fitting it to a rod then using it with abrasive compounds to pass repeatedly up/down the bore grinding-out imperfections to achieve a smoothly finished surface for bullets to ride down. - There is the second way of doing this which is to fire the gun having smeared the bullets with fine abrasive compounds that should result in an improved surface at some time later .. this 'fire-lapping' might be a better science to some degree as the chamber-end would be more polished while the muzzle end should be less abraded making for the resulting barrel-bore taper and tighten progressively ??

I am not recomending this lapping process in any way - as to me - it seems like a fast way to wear-out and use-up the life expectancy of an expensive tool .. BUT the resulting improvement in performance could well justify.

Here's a "side story" .. Back in the '70s-'80s I owned a couple of Ford Cortinas bought used from dealers - as the mileage built to around 70 thousand miles, the petrol motors freed-up and performance improved nicely - then both British made engines blew-up - Impressive eh.

When staring down the barrel of either antique Colt - I'm surmising that both of my guns have in the past been "cleaned" by someone using wire brushes spun in the bores using an electric drill .. nice.

I'm inclined to think that modern firearms shooting jacketed projectiles are best not interfered with .. particularly when there may be hard chrome plating, Stellite, Tenifer, nDLC, whatever in the tech. spec.

However if you are shooting blackpowder with LEAD 'Conicals' or spherical Balls through rifled bores, this is a whole different ball-game. - When loading lead projectiles into your revolver you are SWAGING a slightly oversized pill into the chambers to give a gas tight fit. - When fired, this ball accelerates from the chamber and jumps-the-gap into the barrel FORCING CONE and starts to OBTURATE or gas-seal itself into the bore and rifling. This is the split second in time where you have the high pressure gasses impacting on the base of the bullet to drive it forward into the world through a precisely designed and smoothly engineered bore, to spin ballistically on an accurate predetermined trajectory ..

YEAH RIGHT .. 

- Unless of course you have an old percussion revolver that Col. Sam Colt built 160 years ago - one that has had a hard life in the gold fields and rain forests of the colonies. - One that has been fired and NOT cleaned - one that has been left for long periods in a damp environment wrapped in cotton rags, for the acidic sulferous fouling to react with the ferrous metal.

That is a 160 year old .31 Caliber Black Powder Revolver that I am trying to improve while retaining it's originality 100%. - Not bad image resolution from a cell phone eh.

According to a Las Vegas U S YouTube shooting correspondant 'SNAFU' - original blackpowder guns that are mechanicaly safe to shoot should be loaded with sensible loads and indeed should be shot at every opportunity ..

My Bore Polishing 'Kit' starts with PVA gluing cotton cloth to a dowel and using it to polish/clean the black hole with metal polish on a stick.

Working from the forcing cone end of the barrel with a linear 'IN-OUT' action rather than spinning .. you can see the polishing cloth conform to the lands & grooves while it smooths the surfaces - This is not grinding a new surface by lapping with abrasives - but rather - putting on a shine. I doubt that any measurable change of dimension more than one tenth of one thousanth of a centimetre results.

My purpose would be to reduce Stiction leading in the barrel, to improve velocities and ease the chore of apres-shoot cleaning.

I have "enjoyed" truly BAD bore leading when trying to shoot swaged lead 9mm bullets from Glocks .. the issue being that swaging needs a soft alloy while it is possible to cast reasonably hard lead.

Of course - flintlock and percussion muzzle loaders need soft pure lead balls to work best.

While noting that ONLY cannon & licensed registered handguns and rifles may be shot currently in New Zealand - I suggest that an optimised bore when loaded with sensible charges and lubricated projectiles will go some way to getting a half-decent result on target.

I will opine that all blackpowder muzzleloading guns SHOULD be totally exempted from NZ Licensing and Registration requirements of  Te Tari Pureke. 

- When if ever, in the last century has any crime wave occurred from the use of a muzzle loading firearm?

Marty K.