Barrels

Dan
I presume the potential 'problems' you listed above is why the quality Button Rifled Barrel Manufacturers Air Gauge their Barrels and Grade them accordingly? Their 'select' or 'ultra match' grades are held to some impressive tolerances so at least you know what you are buying.
Yorkie.

Hi,

Apologies, I was talking to Wade from Shilen at the Shot show, and the way he described it to me was that they are more concerned with the dimensions of the starting hole, hence the usefulness of the air gauge. Obviously the more consistent that hole is the more consistent the force of the button is through the barrel, and the more consistent the dimensions and twist rate will be from barrel to barrel.

he described the difference in Match to Super match to me as the amount of time spent lapping to alleviate tight and loose spots and getting a consistent feel on the lap through the barrel. I suppose it follows suit that they would use a diiferent form of air gauge gauge again, and I'm sorry for going off on one about this.
 
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A cleaning rod with a dry patch will reveal a lot about a barrel. With a sympathetic touch you can detect very minor irregularities in the bore, as you drag it through.

This was some of the best advice I have had, from an old boy, when I started. I think it has saved me from several costly mistakes.

If buying from a dealer, also insist on being allowed to use the borescope.

If they don't have a borescope, run, don't walk, away.
 
Hi,

air gauging of button barrels is performed at the stage where the blank has been drilled and reamed, and is simply a QC test on the dimensional uniformity of the starting hole. It is not a measurement of the finished rifled barrel, and has no bearing on the dimensions of the finished barrel, nor the uniformity of the twist rate. An air gauge can only be used on a cylindrical feature.

Hi Dan
Thanks for that, i did not know that is what air gauging meant.
Shilen say on their site that their select match must have a groove diameter air gauged within .0003" of standard diameter. Does this imply they can air gauge the finished barrel?
Thanks.

Yorkie
 
Ed Shilens explanation of air gauging:

Air gauging is the method used to determine the fluctuations of land and groove heights in the interior of the barrel by using a constant flow of air through a probe. The gauge is adjusted to a given mean using a true, determined sizer head. The probe is then inserted into the barrel. The operator watches the fluctuations from the mean as the probe is moved through the bore. Our air gauges are accurate to 50 millionths of one inch.

Ian.
 
With regards to the honing of Bergara barrels, this is all done by CNC to very high tolerance, any high spots are removed leaving a very uniformed finished. I watched the whole process start to finish at the factory. I also used a set of deltronic pins on several barrels and they seemed flawless at the time...that was in 2008!


Id be happy with a button rifle barrel...cut rifle barrels, whilst accurately produced are dependant on the cutter box wear, the cutter itself being ground before or during rifling and of course ultimately the quality of the barrel material.
 
cut rifle barrels, whilst accurately produced are dependant on the cutter box wear, the cutter itself being ground before or during rifling and of course ultimately the quality of the barrel material.

Some years ago one of our very few UK rifle manufacturers (not 'smiths) decided to change their (also UK ;)) supplier of barrels and go elsewhere. I don't know the ins and outs, but understand it was not for commercial reasons.
 
AFAIK you can buy the barrels as profiled or plain blanks too. It is arguable whether cut rifling has any real superiority over a well made buttoned or hammered barrel. Certainly I wouldn't expect them to be as good as the very best, given the price.

I'll die a happy man if I know what the heck 'AFAIK' means. Can anyone enlighten me?

Am I the only person on here that gets irritated by abbreviations and poor grammar?

Kind regards,

Tim
 
I'll die a happy man if I know what the heck 'AFAIK' means. Can anyone enlighten me?

Am I the only person on here that gets irritated by abbreviations and poor grammar?

Kind regards,

Tim

I believe it means, "as far as I know"
 
Thank you Mongoose. It wouldn't be a hardship to type it in full would it?

Kind regards,

Tim
 
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