Author Topic: Gunners quadrant (Read 1790 times)

Victor3 · « **on:** February 15, 2009, 02:12:38 AM »

Just received this today.

It's about 6" x 7". Mostly brass construction, and the bubble level works. Color even matches my French 75.

Don't know how useful it will be for my cannons, but it looks neat...

KABAR2 · « **Reply #1 on:** February 15, 2009, 02:42:29 AM »

Victor,

It depends on how much indirect fire you plan on doing....... make sure you have a good forward observer

Victor3 · « **Reply #2 on:** February 15, 2009, 02:57:57 AM »

Quote from: KABAR2 on February 15, 2009, 02:42:29 AM

Victor,

It depends on how much indirect fire you plan on doing....... make sure you have a good forward observer

Why thank you for offering, Kabar. I'll supply the hardhat!

cannonmn · « **Reply #3 on:** February 15, 2009, 03:28:06 AM »

The way I've used them is to re-set the same elevation I had for the previous shot, with larger cannons anyway. When a wheeled carriage is on turf, especially turf that may not be flat and even, you can't count on the gun being at the same elevation every time after you physically roll it back in battery. The quadrant helps, when you need to make adjustments, you first set the elevation back to what the quadrant says it was for previous shot, then do whatever number of turns on the elevating screw you think needed. Then set the quadrant for that elevation before firing. All you have to do is elevate until the bubble is centered, don't have to worry about reading mils or anything that way. I'm sure there are better ways to use it with ML arty but that's what I've done occasionally.

Rickk · « **Reply #4 on:** February 15, 2009, 03:39:32 AM »

Here is mine

Harbor Freight - 0.1 degree digital resolution, magnetic base - $28 bucks.

Rick

Double D · « **Reply #5 on:** February 15, 2009, 03:51:57 AM »

what should I expect to pay for a gunners quadrant and a where do you get one?

cannonmn · « **Reply #6 on:** February 15, 2009, 04:37:27 AM »

The common US Army gunner's quadrants as shown, I've seen for maybe $50.-$125. sometimes more, depending on condition, whether orig. leather case is with it (later ones had nice hard plastic case). Ebay is probably best bet for a cheap one that you'll be able to find fairly quickly, also good chance of getting one cheap there. The smaller ones were made for use with machine guns, but that probably wouldn't bother you if it would work for casual cannon shooting.

Note that it helps a lot to have a flat surface on top of the cannon on which to place it consistently. All military cannons made since maybe about the 1880's have a flat place on top of breech that has marks for quadrant placement. When the piece is made, that surface is machined to be exactly parallel to the bore axis.

Victor3 · « **Reply #7 on:** February 15, 2009, 04:48:18 AM »

Quote from: Rickk on February 15, 2009, 03:39:32 AM

Here is mine

Harbor Freight - 0.1 degree digital resolution, magnetic base - $28 bucks.

Rick

I think "there's an app for that" on the new iPhone. Really, I think I saw one!

Victor3 · « **Reply #8 on:** February 15, 2009, 04:51:57 AM »

Quote from: Double D on February 15, 2009, 03:51:57 AM

what should I expect to pay for a gunners quadrant and a where do you get one?

I paid $60 shipped for mine on Gunbroker. I see Numrich and Sarco have them, but they cost a bit more.

cannonmn · « **Reply #9 on:** February 15, 2009, 04:54:17 AM »

Here's the only one current Ebay offering I could find, condition is typical, price is pretty good, however it is in the UK. I think links to current auctions are against board rules, but you can find it searching collectibles category for "quadrant m1."

Ex 49'er · « **Reply #10 on:** February 15, 2009, 05:24:39 AM »

The little machine gun ones work just like the bigger arty ones and are usually much cheaper. There is a big quadrant on fleabay now for $39 and counting with a little over 2 days left in bidding.

KABAR2 · « **Reply #11 on:** February 15, 2009, 07:08:41 AM »

The M1917 browning quadrent runs around 75.00 with out the leather case, if people know what they have,

And Victor I have my tin hat, you supply the sand bags and field phones,

dan610324 · « **Reply #12 on:** February 15, 2009, 07:33:24 AM »

why not build by yourself ??

here are some drawings

dan610324 · « **Reply #13 on:** February 15, 2009, 07:36:23 AM »

some more

Will Bison · « **Reply #14 on:** February 15, 2009, 08:16:52 AM »

The Digital Angle Gauge that Rick posted is what I've been using since last Summer. When I ran out of rear sight elevation we used the Gauge to get out a bit further. I set up an aiming stake and used the front sight for azimuth and the Gauge for elevation. Worked darn good.

On the other end, I also find the Gauge useful around the shop.

Double D · « **Reply #15 on:** February 15, 2009, 04:06:27 PM »

How would use one of the gunners quadrants on say one of Dominicks Dictators

seacoastartillery · « **Reply #16 on:** February 15, 2009, 04:38:00 PM »

Either one of the modern quadrants shown on this thread can be used on Dominick's Dictator mortar. Simply adjust the bubble level arm to any elevation at which you wish the mortar to shoot and tighten it. Place the base of the quadrant on the muzzle face of your mortar and elevate the tube until the bubble is within the level limit lines. Vary the powder charge to change the range. As a VERY general rule, 45 Deg. is used for maximum range shooting and 60 to 70 Deg. is used for shooting over high hills or other obstacles as the descending branch of the projectile's trajectory is more vertical than that produced by the 45 Deg. elevation setting.

An interesting topic,

Mike and Tracy

Ex 49'er · « **Reply #17 on:** February 15, 2009, 05:16:51 PM »

While I have used the military quadrants in the past; I am currently using something a little easier these days with my mortar.
http://www.sears.com/shc/s/p_10153_12605_00981548000P?mv=rr
This one is available for $15. There is a smaller one for $5.00.

Cat Whisperer · « **Reply #18 on:** February 16, 2009, 12:52:15 AM »

It would be useful for researching what the actual max-range elevation-angle is for each type of projo.

I have a 1917 type.

Terry C. · « **Reply #19 on:** February 16, 2009, 02:50:13 AM »

Quote from: Ex 49'er on February 15, 2009, 05:16:51 PM

There is a smaller one for $5.00.

I have one of those $5 ones from Sears. It's okay, but I don't recommend it. I need something a little more sensitive, and a lot easier to read. I'm thinking digital...

I have a protractor head for a Brown & Sharpe combination set at work, but that stays there. It's very accurate although I need a magnifying glass to read the tiny graduations.

ShadowMover · « **Reply #20 on:** May 28, 2011, 08:21:07 AM »

You get what you pay for. The M1 Gunner's Quadrant is marked in 'mils', which is an abbreviation for milliradian.
http://en.wikipedia.org/wiki/Radian

The Angular mil used by most western military organizations is 1/6400 of a circle. 6400 mils= 360 degrees.
http://en.wikipedia.org/wiki/Angular_mil

The bubble vial on these M1 Quadrants is much more sensitive than any magnetic stick on job you buy at the lumberyard or at a discount tool store. They will easily read 1 mil which corresponds to about 1 meter at 1 kilometer (about 39" at .6 mile). The fine graduations between the dial would allow approximations down to 0.1 mil.

It's more accuracy than most need, but if you are not elevated correctly, all the other error factors just add up quicker. BTW, mine was from ebay for $51 total. I bought another at a swap meet in Quartzsite, AZ with a busted bubble vial for $27. Doing the research on replacing the vial lead me to conclude I couldn't afford to buy that kind of quality, and it was cheaper to bid on another quadrant. Anybody need any spare parts for one of these?

1mil=3.375 MOA

Parrott-Cannon · « **Reply #21 on:** May 28, 2011, 02:37:32 PM »

Attached is a link to a U.S. Army on Gunner's Quadrant

http://carl.army.mil/wwIItms/TM9_1527_1943.pdf