doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com brownells barrel thickness gauge

Just for clarification, the Brownells gauge (I have) is a Manson. I think the spring the original post refers to is the spring loading of the plunger in the dial gauge. This is the only spring present and is very light. It is built into the dial gauge and cannot be strengthened as it works through the light precision mechanism of the dial gauge.

The Brownells/Manson gauge is as I said above quite tricky to use, but with care I'm able to get consistent results and it is very much cheaper than some of the more satisfactory offerings I have seen (which are often many times the price).

I've seen the Manson gunge modified by putting a leaf spring on the bottom bar. The spring rubs against the opposite wall to make point opposite the gage follow the wall more closely. Anybody here have experience with that modification?

pooch, this is my original rendition of the Mason gage that I made. This is the modification that eightbore stated that Dr. Gaddy used.



This is also not a friendly gage to use as you need someone to write your figures down, as I copy all my readings of the ones I measure.

As to the spring tension on the dial indicator, why would you need more tension on the needle?

I just spent an hour and three beers trying to come up with the precise reading.I could not come up with a reading that I would want to be the expert witness in a court of law.I did clamp the barrel to a table and put some Styrofoam behind the ball to keep it closer to the inside the barrel but I am not sure that worked any better than nothing.. I am going to try foam rubber next.I am sure of one thing RookHawk is right my W.C.Scott measured about .045 to .050 thickness 9 inches from the breech which makes me think it needs to at least be that thick 9 inches from the breech buy this was a 13 bore.

Jewler and Pooch,
Have faith! I too purchased a Manson wall thickness gauge from Brownells and mounted it to a wall and immediately figured out that there was no way to get accurate, repeatable readings and thought gee, that was a waste of $100.00!
After much research, I have discovered that the way to use it is exactly as Eightbore described. Use it just like the Hosford gauge.
Watch the Hosford video to get an idea about what we're talking about. Then thread a piece of rope or webbing through the hole in the centre of the gauge. Zero the unit by holding the rope (so you do not influence the reading)and the sides of the ball. Slide it into the barrels and read away! Make sure that the ball is the only part touching the inside of the bore otherwise you will get a false reading. It is easy enough to get the hang of provided you can keep the barrels in place. I suggest putting the barrels on a bench and anchor them down with a couple of bags of shot. Pre load the plunger with .200" (as I recall) as per the instructions.
I can get accurate, repeatable readings with this method and I think it is useless if fixed in a vertical position.
Gravity does the work of keeping the ball in contact with the inside of the bores and the plunger is not affected as it is on the opposite side.

I think I got it.YOu had me lost with the loop on the rope but I see what you mean now.I still might do what 8 bore did and have a leaf spring put on the back of the ball.

Thanks Blue Grouse and 8 bore only problem now is that when I measure the W.C Scott these tubes are less than .020 but theis is about 9 inches from the muzzel it is .045 9 inches from the breech. Hummmm

The Galazan vertical gauge is the one to buy. There is no question on its accuracy. Too heavy to take to shows? EZ solution, you keep it in the car, leave driver's license or something else of value with vendor that owns the gun, and take the barrels only out to the car and measure them. Unless you're an inveterate tire kicker, how many guns are you going to measure at a show? Or mayhaps you like to impress people that you're smart enough to own a wall gauge and like to show off your portable one? Much ado is made of walking gun show rows with portable wall gauge but try it some time. It's a hassle to carry around and when you rest it on adjacent table to pick up a gun the vendor there complains that you're taking up his table space and you might scratch his guns on display. Or try walking with the gauge in one hand and a bag of goodies you bought in the other. Portability of these tuning fork type gauges is good in theory only. Just get the Galazan and forget about writing up long tomes to convince others that your portable gauge is accurate and repeatable and is so, so very EZ to use at shows.

Dog fox I agree with everything you are saying but am cheap.After doing what 8 bore and blue grouse said it seems to more consistant and if I put a leaf spring on the back I think it would help it more.

Blue Grouse has figured out and explained my method exactly. By the way, I do NOT use the Gaddy spring. It is not needed when you use my and Blue Grouse's method. As Blue Grouse explains, gravity is sufficient. Good luck.