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Forums10
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Most Online1,335 Apr 27th, 2024
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Joined: Mar 2009
Posts: 2,018 Likes: 50
Sidelock
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Sidelock
Joined: Mar 2009
Posts: 2,018 Likes: 50 |
I cannot say I agree that the manson gauge is without merit. While it does not offer the quality of measurement that either the Hosford or Galazan gauges do, it does offer a much better than nothing solution. Further the dial can be swapped for a digital one from harbour freight.
I admit it is not prefect, but it is far better than flying blind and I expect it is close enough to rule out borderline guns
Michael Dittamo Topeka, KS
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Joined: Feb 2002
Posts: 14,125 Likes: 198
Sidelock
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Sidelock
Joined: Feb 2002
Posts: 14,125 Likes: 198 |
Rabbit, you are right about the barrel holding situation. It should be a piece of cake to design some bracket to hold and rotate the barrels, eliminating the need for a helper. However, I measured a pair of second tier English game guns at an auction using a friend for a helper. He had never seen a Manson gauge before and had no trouble holding the barrels to the table for the ten minute procedure. As far as finding and maintaining "zero", the Manson, used horizontally with the eye hook, is as reliable as the Galazan table gauge or the Hosford.
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Joined: Jul 2005
Posts: 7,065
Sidelock
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Sidelock
Joined: Jul 2005
Posts: 7,065 |
Well, at the risk of a scolding from eightbore, the "Truth Tool" made by Johnathan Poole has been around for a dozen years at least and is the original horizontal tuning fork type wall thickness gauge and would appear to be much easier to use than the Manson. It was designed to be used in the horizontal position. Its upper fork is longer and can be hung in the end of the barrel when you are zeroing the gauge. The block has a hole in it that is large enough (1-1/2"?) to be hung from your thumb. It must be "hung" on the thumb so you don't torque the forks and throw off the reading.
It was $200 the last I knew.
I get repeatable measurements from it. On three different barrels I measured the minimum wall thickness with my Truth Tool and got within 1/1000th of Kirk Merrington's measurement. I measured them before I sent them to Kirk for some work.
Best,
Mike
Last edited by AmarilloMike; 09/12/12 10:34 AM.
I am glad to be here.
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Joined: Feb 2002
Posts: 14,125 Likes: 198
Sidelock
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Sidelock
Joined: Feb 2002
Posts: 14,125 Likes: 198 |
Not a scolding, Mike, but I am very familiar with Jon Poole's Truth Tool. I was in Vegas at the Riviera when he introduced it to the American market. It is identical in use to the Manson tool. The Manson tool is zeroed while out of the barrel, holding the "ball" in one hand and the loop in the other. If you want to hang the Manson by the thumb, you can do it. You can put a block with a 1 1/2" hole in it or use a rope loop, like I do. The result is the same.
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Joined: May 2010
Posts: 1,528 Likes: 80
Sidelock
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Sidelock
Joined: May 2010
Posts: 1,528 Likes: 80 |
Having measured the same barrel on two different gauges I got a different reading of.001" . You can also get a discrepancy if the gauge is perfectly square on the table as the weight of the barrel "leaning" if only a fraction can give a false reading . Lets face it if a barrel wall measures .015" one gauge and .016 on another ,a .001" makes no real difference .
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Joined: Feb 2004
Posts: 13,879 Likes: 15
Sidelock
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Sidelock
Joined: Feb 2004
Posts: 13,879 Likes: 15 |
My recollection of various company's metrology (gauge calibration/cert) and inspection departments was that they would advise using an instrument capable of 1/10th the required tolerance. So, if you have a tolerance band of +/-.010", you should use an instrument capable of repeatable accuracy to .001". If you need +/- .001 on the part, you should use an instrument repeatble accuracy of .0001".
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Joined: Jul 2005
Posts: 7,065
Sidelock
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Sidelock
Joined: Jul 2005
Posts: 7,065 |
My Truth Tool is not accurate to 0.0001"(one ten-thousandth). But I have no doubt it is at least accurate to plus or minus 0.001" (one thousandth) which to my mind is adequate for my purposes.
I am glad though that you airplane guys are so anal retentive about accurate measurements. Mechanical failures at 30,000 feet while traveling 500 mph could really ruin a day.
I am glad to be here.
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Joined: Apr 2002
Posts: 6,812
Sidelock
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Sidelock
Joined: Apr 2002
Posts: 6,812 |
Chuck of all people knows that the limiting factor of repeatable accuracy in long calipers is rigidity and that sufficient rigidity isn't available in most materials with a diameter which will slip inside a shotgun barrel of 12ga. or under. Did you go any further with your experiment with carbon composite as either arm of the WT gauge, Chuck?
jack
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Joined: Dec 2001
Posts: 3,964 Likes: 89
Sidelock
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Sidelock
Joined: Dec 2001
Posts: 3,964 Likes: 89 |
The main problem with most of these wall thickness gauges is they are supplied with a very cheap dial caliper. Once I got that figured out I purchased a high quality Starrett dial caliper from eBay. Since then my readings have been much more consistent and I have a lot more faith in the results. The Manson design has nothing I could fault, except at that price it would have to have the very cheapest gauge available.
When an old man dies a library burns to the ground. (Old African proverb)
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