Match grade and lapping.

T

tjensen

New member
While at school I was told that basically the only difference between match grade barrels að standard(cheap) barrels is that the match grada barrels are lapped.
Ive lapped quite a few but my borescope does not agree with this theory.
Am I maybe not lapping enaugh or.......?

Would be interresting to hear from knowledgeable people on this.
 
tjensen said:
While at school I was told that basically the only difference between match grade barrels að standard(cheap) barrels is that the match grada barrels are lapped.
Ive lapped quite a few but my borescope does not agree with this theory.
Am I maybe not lapping enaugh or.......?
.
Click to expand...
What "they" told you at school was wrong. Think it through. A barrel is a manufactured item. Each operation performed (or skipped) will have variance, as does the inspection and grading of that operation. Beyond that, there is no "standard" for inspection and grading, hence no standard for "match." Even worse, the term "match" is no guarantee of performance -- we still do not know enough to predict just how a given barrel will perform, or why, if a barrel performs very well, it did so.
 
Yes Charles that seems obvious but...........

We went to two factories, Shaw and Douglas. In both they made all barrels the same, no special machine that made "match" barrels.
After that they air guged them and I think most if not all barrels pass that test today.
Straightened them next. Then the best were taken aside, lapped and called match.

I´m also wondering when have I lapped to much?
Also, how to go about lapping chambered barrels?

Really would like more input on this.
 
tjensen -- as far as I know, Douglas does not lap barrels, period. Stan Taylor of Douglas is a friend -- from whom I've ordered barrels -- and the difference between their "select" barrels, however they term it, is in the result of the air-gauge test. I believe their best barrels show something on the order of .0001, regular barrels may show .0003.

You really need someone more knowledgeable about the different manufacturers than I -- Butch Lambert, maybe or Frank Green, or Greg Walley, or someone quite familiar with the different shops and techniques. They may or may not see this post.

But I do know that the general answer to your question is no. There is far more difference between a "match" barrel and a "regular" barrel -- particularly a factory barrel -- than hand lapping. I would guess, but do not know for sure, that after point, you are apt to do more damage than good with hand-lapping.
 
E R Shaw doesn't make a match grade barrel.

Douglas does.

Lapping your own barrels is worse than useless and you can't properly lap a chambered barrel, period. On even the best match barrels you throw away the 'belled' portion where the lap reverses. And it IS belled, and often eccentric, on every brand of true match grade barrel.


moreopinionsby





al
 
Worse than useless?
No, thats not true.
Ive seen big difference, but of course not benchrest qality yet.
No big magic in lapping, if they can do it we can do it.
 
tjensen,
I can see you haven't gotten your feet wet yet. NO BIG MAGIC in lapping! I can tell for sure your feet aren't wet yet. Do it for a few years and come back and post your scientific results.
Papaw
 
yep, douglas doesnt lap 'em, and im not aware of anything shaw makes that is truly considered a "match grade" barrel. talk to, or read what is written by the better barrel makers who offer lapped barrels, and they will all tell you it is a difficult skill to master. better to buy a premium lapped barrel blank, and if its bad, they will normally replace it, if you hack the heck out of it lapping it yourself, and it doesnt shoot, who buys the barrel. IMO, most gunsmiths who lap barrels are doing more harm than good, even though every last one will tell you "they know what they are doing"!
 
tjensen said:
Worse than useless?
No, thats not true.
Ive seen big difference, but of course not benchrest qality yet.
No big magic in lapping, if they can do it we can do it.
Click to expand...

You pour your own laps? What material do you use? How long?

tx

al
 
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