Many statement(s) in Riffle's book on the Model 12 should be viewed with bit of skepticism.
The book itself is full of upgraded and non-factory work presented as Factory.
Most all upgraded engraving was done by one guy,,the wood work by another.
The statements about the complete disassembly to check for flaws after the 'proof round' going thru the gun are conjecture at best.
A line assembled gun in a factory ,,anyones factory,,went into the range fully finished and assembled.
I don't think Dave Riffle ever work in the industry. He never mentioned it in times I spoke with him.
In the Range the gun gets a proof round,,then several 'function' test rounds'. At some factorys and for some firearms they then fire(d) w/a few more to target the rifles and handguns in on paper.
A quick hand & eye inspection, ,,proof mark wacked in place,,cleaning rod down the bore (or not) and off to the packing/shipping dept.
Get 'em out the door is the goal,,just like any other factory.
There is absolutely no time & labor for anyone to complete disassembly an already assembled and finished proofed firearms to go on an egg hunt for internal issues with them.
Maybe that would be nice to believe,,but it doesn't happen with production guns.
A very few special project/high grade/presentation type guns get hand walked thru the process so they get kid glove treatment in the Range.
But that's it.
Even they don't get taken apart again.
They trust their product enough not to have to do that.
Hundreds and hundreds of M12's a day going thru there,,no one is going to on the job to then take them back apart and inspect them for problems. There shouldn't be any. If there was,,the Proofing/Function /Targeting & Final hand&view inspection was supposed to catch any.
Proof rounds are mfg by most of the major ammo mfg's.
Some not in all the calibers of the rifle and pistol, but most make the standard shotshell rounds.
They are plainly marked as such.
SAAMI has an industry standard psi limit for each caliber and gauge.
Their Proof standards are based not on a simple % over what the standard Service/Field pressure for the cal/ga is.
But instead a set of formulas using the Max & Min Probable Mean pressures multiplied times constant.
Then rounded up or down by 500.
Shotshell proof rounds must use the slowest burning powder available to reach the peak pressure between the chamber and the measurment point along with the max shotload that the gun is being certified for.
The Service pressure of the 12ga 2-3/4 is 11,500psi
The SAAMI proof pressure round for the same is 19,000psi.
SAAMI itself has been around since the 1920's but their dive into cartridge and pressure specs for the private firearms industries in the USA didn't really come about till the very late 50's and into the 1960's.
Winchester likely loaded their own Proof ammo back in the day.
What the pressures were then I don't know.
The 19,000psi mark used now is pretty close to that 200% proof mark.
Some will be lower and some higher of course from the same lot.
The book itself is full of upgraded and non-factory work presented as Factory.
Most all upgraded engraving was done by one guy,,the wood work by another.
The statements about the complete disassembly to check for flaws after the 'proof round' going thru the gun are conjecture at best.
A line assembled gun in a factory ,,anyones factory,,went into the range fully finished and assembled.
I don't think Dave Riffle ever work in the industry. He never mentioned it in times I spoke with him.
In the Range the gun gets a proof round,,then several 'function' test rounds'. At some factorys and for some firearms they then fire(d) w/a few more to target the rifles and handguns in on paper.
A quick hand & eye inspection, ,,proof mark wacked in place,,cleaning rod down the bore (or not) and off to the packing/shipping dept.
Get 'em out the door is the goal,,just like any other factory.
There is absolutely no time & labor for anyone to complete disassembly an already assembled and finished proofed firearms to go on an egg hunt for internal issues with them.
Maybe that would be nice to believe,,but it doesn't happen with production guns.
A very few special project/high grade/presentation type guns get hand walked thru the process so they get kid glove treatment in the Range.
But that's it.
Even they don't get taken apart again.
They trust their product enough not to have to do that.
Hundreds and hundreds of M12's a day going thru there,,no one is going to on the job to then take them back apart and inspect them for problems. There shouldn't be any. If there was,,the Proofing/Function /Targeting & Final hand&view inspection was supposed to catch any.
Proof rounds are mfg by most of the major ammo mfg's.
Some not in all the calibers of the rifle and pistol, but most make the standard shotshell rounds.
They are plainly marked as such.
SAAMI has an industry standard psi limit for each caliber and gauge.
Their Proof standards are based not on a simple % over what the standard Service/Field pressure for the cal/ga is.
But instead a set of formulas using the Max & Min Probable Mean pressures multiplied times constant.
Then rounded up or down by 500.
Shotshell proof rounds must use the slowest burning powder available to reach the peak pressure between the chamber and the measurment point along with the max shotload that the gun is being certified for.
The Service pressure of the 12ga 2-3/4 is 11,500psi
The SAAMI proof pressure round for the same is 19,000psi.
SAAMI itself has been around since the 1920's but their dive into cartridge and pressure specs for the private firearms industries in the USA didn't really come about till the very late 50's and into the 1960's.
Winchester likely loaded their own Proof ammo back in the day.
What the pressures were then I don't know.
The 19,000psi mark used now is pretty close to that 200% proof mark.
Some will be lower and some higher of course from the same lot.
