Fire Lapping Blue & Stainless

[1895GG]

I just received your firelapping kit and I am going to lap both a Marlin 1895G and 1895GS.  In your instructions, you mentioned about chrome bores and Ruger Stainless bores.  I do not find anything about either bore being chromed.  Can I expect the stainless to require more lapping than the blue assuming both are about the same quality of finish?

[Veral]

I have never enountered, nor had customer comments about any stainless barrels that lapped enough harder than blue to make a difference,  except Ruger stainless.  Seems to me that it would be impossible to shoot out a Ruger stainless barrel, judging by how hard they are to lap.  Have any of you shooters out there put enough rounds through one to know whether they with stand the erosion of hot powder better than blue steel?

  While I'm diverted on this subject, hot cast bullet loads will shoot out the throat of a barrel about as fast as jacketed loaded to the same intensity.  The belief that cast will never wear out a barrel only applies if mild loads are used, as has been mandatory with lead until LBT began teaching how to get more zip.  I lengthened the throat in a 30-06 test rifle by over an inch in a few months when developing my lubricants and cast bullet designs.  Ditto a couple magnum revolvers.  Stick and flake powders burn hotter and erode steel faster than ball powders, as a general rule,  and the hotter the loads the faster they cut.  I was running WAY over SAMI max pressures with most of my loads which caused the wear.  Part of the cost of doing business, one could say.

[haroldclark]

I have firelapped a Ruger 308 Stainless barrel and didn't notice any difference between it and a blued barrel.  The Ruger barrel in mention would collect copper, but otherwise shot fine.  I wanted to shoot cast bullets and had a tad bit of leading.

I used LBT firelapping cast bullets and fired 50 of them through the barrel.  After that, there was no leading or copper fouling.  After firelapping, I ran Sweets 7.62 through the barrel after firing jacketed bullets and there would be no trace of bluing from the copper.

It still shoots fine after 5 to 600 rounds of jacketed ammo.

I only have two rifles that have not been firelapped and they are both CZ 550s.  I shoot cast bullets in both, mostly.  (my 223 Remington has not been firelapped either).  I have a bunch of rifles and other guns.

Harold Clark

[Veral]

Thank you for the report.  

   It is tough to keep ones feet out of his mouth when answering questions for  public reading!   As anyone can see, I make my answers very broad to try to cover all questions related to the subject, rather than just answer  a question simply as possible, and that approach makes me more vulnerable to 'foot in the mouth' problems.  So be it.  We both know now.
   To clear up my answer considerably, Ruger stainless may be different now that they are using hammer forged barrels of their own manefacture, and for sure, the hammer forged barrels which Ruger now produces are of the highest quality.  Because they are so precisely made and smooth inside, minimal lapping is required to make them an ultimate shooter.

    With the cut rifled barrels Ruger used prior to setting up their own hammer forging machinery, internal dimensions weren't the best and many were quite rough, compared to hammer forged.  And, perhaps the steel was a different type, I don't know, but one could expect so, because hammer forging crushed the metal around a mandrel,  which could require different characteristics than for cutting the rifling.  At any rate, the cut rifled barrels used until sometime in the mid 90's, especially revolvers where a severe constriction can be created at the threads which connect barrel to frame, the lapping process can be long and tiring, but still well worth doing, because a lapped barrel is always the ultimate in precision, reguardless of poor quality or good when manufactured.  Understand that diameters increase slightly from lapping, which doesn't appear to hurt with jacketed, and certainly makes no difference to lead when I make the molds, because I cut for your individual gun.

[Veral]

Thank you for the report.  

   It is tough to keep ones feet out of his mouth when answering questions for  public reading!   As anyone can see, I make my answers very broad to try to cover all questions related to the subject, rather than just answer  a question simply as possible, and that approach makes me more vulnerable to 'foot in the mouth' problems.  So be it.  We both know now.
   To clear up my answer considerably, Ruger stainless may be different now that they are using hammer forged barrels of their own manefacture, and for sure, the hammer forged barrels which Ruger now produces are of the highest quality.  Because they are so precisely made and smooth inside, minimal lapping is required to make them an ultimate shooter.

    With the cut rifled barrels Ruger used prior to setting up their own hammer forging machinery, internal dimensions weren't the best and many were quite rough, compared to hammer forged.  And, perhaps the steel was a different type, I don't know, but one could expect so, because hammer forging crushed the metal around a mandrel,  which could require different characteristics than for cutting the rifling.  At any rate, the cut rifled barrels used until sometime in the mid 90's, especially revolvers where a severe constriction can be created at the threads which connect barrel to frame, the lapping process can be long and tiring, but still well worth doing, because a lapped barrel is always the ultimate in precision, reguardless of poor quality or good when manufactured.  Understand that diameters increase slightly from lapping, which doesn't appear to hurt with jacketed, and certainly makes no difference to lead when I make the molds, because I cut for your individual gun.