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I would appreciate input from both recent purchasers of Cardinal 6.8 SPC barrels as well as those who have considered purchasing a Cardinal barrel but have been hesitant to do so because of Tim Hick’s barrel disclaimer. As many of you know Tim cannot guarantee that his existing barrels in inventory can successfully shoot SSA combat loads due to concerns that SOME small percentage of barrels may generate excessive pressure due to the possibility of an undersize bore.
I have recently purchased a fairly large quantity of his barrels in nearly every length and configuration and gaged them with precision pin gages for minimum bore to find only one barrel that has not been within tolerance. This barrel showed signs of localized chrome buildup in several areas of the bore, which I recently reported on the forum.
When word of my measurements got out, two individuals contacted me. One asked that I perform a measurement service of his Cardinal barrel to insure the minimum bore diameter was within allowable tolerance, and the second individual asked if I would sell one of the barrels that had gaged within tolerance.
This led me to thinking that others might have similar interest in having their barrels checked or in purchasing a barrel that had passed the checks I have performed.
So my question is this:
Would there be interest by those on the forum in purchasing new Cardinal barrels that had the following done:
1. Remove the gas port burr using an industry standard deburring tool designed to remove burrs in small diameter blind holes. This would insure that the gas port burr is properly and carefully removed before the weapon is assembled. This tool is used extensively in the hydraulic valve industry to remove similar burrs in critical port and passage intersections where conventional deburring is not possible.
2. Using the owner’s supplied 6.8 bolt or a 6.8 bolt supplied by me…check the headspace of the barrel with 6.8 SPC go/no-go gages to insure headspace is correct.
3. Using precision ground Z series pin gages…measure each barrel to guarantee that the minimum bore diameter is within the correct specification of .2700� or greater. This would NOT be a measurement of the groove diameter. This also would not be a guarantee that the barrel would be able to shoot SSA combat loads. Rather, it is simply several checks designed to determine if a barrel you already have is within minimum bore specification and has correct headspace or insure that a new barrel you are buying is within minimum bore tolerance and has correct headspace. The removal of the gas port burr is an added benefit to insure that a gas port burr is not confused with a restricted or undersize minimum bore.
In the event that a owner supplied barrel does not pass the inspection process, it would simply be returned with an attached description of those deviations that were not within tolerance. Depending on the degree of variation, the barrel may still be fine for standard commercial loads or may still be marginally acceptable for combat loads...but at least you will have an accurate assessment of the minimum bore diameter and headspace of your own barrel.
Is this a service that would interest current owners and potential buyers of the few remaining Cardinal barrels available?
If so… what is this service worth? What would be a reasonable charge to perform these checks on your existing barrel or new barrel to provide the peace of mind knowing that the minimum bore is correct, the headspace is correct and the gas port burr has been removed?
If there is more than passing interest... I would consider buying additional barrels above the 17 already purchased, and performing these checks for prospective buyers.
Your comments, both pro and con would be appreciated.
Kerry
BTW, for those who may not know my background…I am a retired Manufacturing Engineer from the machine tool, piston ring and tactical aircraft industries. I was a journeyman Tool Room Machinist, CNC Programmer and owner /operator of a small four man machine shop in the St. Louis area during the mid 70s’ to mid 80’s.
I have recently purchased a fairly large quantity of his barrels in nearly every length and configuration and gaged them with precision pin gages for minimum bore to find only one barrel that has not been within tolerance. This barrel showed signs of localized chrome buildup in several areas of the bore, which I recently reported on the forum.
When word of my measurements got out, two individuals contacted me. One asked that I perform a measurement service of his Cardinal barrel to insure the minimum bore diameter was within allowable tolerance, and the second individual asked if I would sell one of the barrels that had gaged within tolerance.
This led me to thinking that others might have similar interest in having their barrels checked or in purchasing a barrel that had passed the checks I have performed.
So my question is this:
Would there be interest by those on the forum in purchasing new Cardinal barrels that had the following done:
1. Remove the gas port burr using an industry standard deburring tool designed to remove burrs in small diameter blind holes. This would insure that the gas port burr is properly and carefully removed before the weapon is assembled. This tool is used extensively in the hydraulic valve industry to remove similar burrs in critical port and passage intersections where conventional deburring is not possible.
2. Using the owner’s supplied 6.8 bolt or a 6.8 bolt supplied by me…check the headspace of the barrel with 6.8 SPC go/no-go gages to insure headspace is correct.
3. Using precision ground Z series pin gages…measure each barrel to guarantee that the minimum bore diameter is within the correct specification of .2700� or greater. This would NOT be a measurement of the groove diameter. This also would not be a guarantee that the barrel would be able to shoot SSA combat loads. Rather, it is simply several checks designed to determine if a barrel you already have is within minimum bore specification and has correct headspace or insure that a new barrel you are buying is within minimum bore tolerance and has correct headspace. The removal of the gas port burr is an added benefit to insure that a gas port burr is not confused with a restricted or undersize minimum bore.
In the event that a owner supplied barrel does not pass the inspection process, it would simply be returned with an attached description of those deviations that were not within tolerance. Depending on the degree of variation, the barrel may still be fine for standard commercial loads or may still be marginally acceptable for combat loads...but at least you will have an accurate assessment of the minimum bore diameter and headspace of your own barrel.
Is this a service that would interest current owners and potential buyers of the few remaining Cardinal barrels available?
If so… what is this service worth? What would be a reasonable charge to perform these checks on your existing barrel or new barrel to provide the peace of mind knowing that the minimum bore is correct, the headspace is correct and the gas port burr has been removed?
If there is more than passing interest... I would consider buying additional barrels above the 17 already purchased, and performing these checks for prospective buyers.
Your comments, both pro and con would be appreciated.
Kerry
BTW, for those who may not know my background…I am a retired Manufacturing Engineer from the machine tool, piston ring and tactical aircraft industries. I was a journeyman Tool Room Machinist, CNC Programmer and owner /operator of a small four man machine shop in the St. Louis area during the mid 70s’ to mid 80’s.
