Valence's M66 Gun Ring

Thank you Valence,
Your dedication to this site and the many questions you've patiently answered speak highly of your character. I know in my case I need better friends. I hope to travel widely when I retire. Maybe we will meet someday. Thank you again.
Goldy

Goldy said:

Thank you Valence,
Your dedication to this site and the many questions you've patiently answered speak highly of your character. I know in my case I need better friends. I hope to travel widely when I retire. Maybe we will meet someday. Thank you again.
Goldy

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You are too kind. My mother would call me impatient

But you are very welcome and by all means ask questions! It's so helpful to have somewhere to ask questions. I've actually seen a very small number of military vehicles in person, fewer deuces, and this is the only M66 gun ring that I've seen in person. I would like to meet more folks too, which means I *should* be attending the Steel Soldier's rally in Georgia this year, but I'm already taking the first whole week of October off from work, so it's difficult to take another.

I hadn't even paid attention to how close the windshield hinge bolt was to interfering with the front gun ring leg until you asked about it! I would like to point out that I edited my previous post as there was one difference in the hinges: The passenger side had a shorter bolt with about 2-3/16" sticking out from the windshield frame vs the driver's at about 2-1/2". I believe that the longer bolt would have interfered.

Thank You Sir!

Goldy

Here are some measurements to help answer some of the common questions that I've been asked:

Hard top hole location & dimensions:
***Warning: The following measurements are not all perfectly precise and some were eye balled. My intent is to help you get pretty close so please use at your own risk and judgment if you plan to cut a hole in your hard top. The pictures that are provided are more for you to see where I measured from, not to see an exact measurement on the pictured tape. I did not cut this hole in my hard top; my best guess is it happened sometime during its service for the Utah Army National Guard.

Cut-out opening:

• ~3-3/4" from the front
• ~5" from the right side
• ~6" from the rear
• Hole diameter varied from 28-1/4" to 28-3-8"

(pictures depict front, right, rear measurements, in that order)


The turret cutout consists of 4 parts:

1. Interior aluminum backing ring
   • 30-3/4" O.D
   • 28-3/4" I.D.
   • 1" wide
   • 1/4" thick
2. Hole in the hard top
   • varied from 28-1/4" to 28-3-8" in diameter
3. Exterior fiberglass/plastic ring (I do not know where you get this)
   • 28" I.D.
4. Vinyl "turret cover" with a spring sewn into the entire outer edge that fit in a lip on the exterior fiberglass ring. (I have not seen one of these for sale, only canvas ones with no spring)
5. Vinyl support, anti-water pooling, see: https://www.steelsoldiers.com/showthread.php?139879-Cab-gun-ring-vinyl-cover-quot-tented-quot

The position of the M66 ring is not centered above the cab cut-out. As can be seen, the ring backrest is almost flush with the rear of the cab cutout.



Gun-ring leg vertical shaft dimensions:
0.20" sidewall thickness
2.25" in diameter
Left-rear leg: ~54-1/2" long
Right-rear leg: ~54-7/8" long
Front-right leg: ~66-1/2" long

Note: The "arm" at the top of the leg shaft is not welded exactly at the top - I'm sure so there was enough material available for a full and proper weld.

Valence, you didn't mention it but did your ring come with a rubber gasket? I bought mine from Chalk and it has a very large rubber gasket that I'm guessing goes between the fiberglass ring and the roof. It appears to have come with the install kit way back when. Less messy than silicone. It's intact but I sure would like a new one just for giggles. It also came with a vinyl anti-rain/snow devise and the spring sewn in the edge. I might try an upholsterer to sew new vinyl on the spring as the old vinyl has weathered and been painted a few times. Pretty stiff. Also, your inspirational pic shows a round rod holding up the cover. That came with my ring also. It has what I can only describe as squares welded to the ends of a bent rod that some how are wedged into the cover and keep it in place. When I start my install I will know more about how and why.

As always, your thread shows much precision in your work and descriptions. The pics are essential to a newbie like me. Many thanks.

Goldy

Goldy said:

Valence, you didn't mention it but did your ring come with a rubber gasket? I bought mine from Chalk and it has a very large rubber gasket that I'm guessing goes between the fiberglass ring and the roof. It appears to have come with the install kit way back when. Less messy than silicone. It's intact but I sure would like a new one just for giggles. It also came with a vinyl anti-rain/snow devise and the spring sewn in the edge. I might try an upholsterer to sew new vinyl on the spring as the old vinyl has weathered and been painted a few times. Pretty stiff. Also, your inspirational pic shows a round rod holding up the cover. That came with my ring also. It has what I can only describe as squares welded to the ends of a bent rod that some how are wedged into the cover and keep it in place. When I start my install I will know more about how and why.

As always, your thread shows much precision in your work and descriptions. The pics are essential to a newbie like me. Many thanks.

Goldy

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There wasn't any gasket on mine at the hard top cutout. There was a lot of white caulk inside and out. I used a razor blade to clean up the exterior fiberglass and interior aluminum portions. I then used clear silicone on the exterior fiberglass only; under it, around the edge, and on each bolt.

Wow great post. Thank you for the information

I am looking for the U-bolts now. I’m not sure if I can find you bolts that will hold up at Ace Hardware or Home Depot

KevinGaus said:

I am looking for the U-bolts now. I’m not sure if I can find you bolts that will hold up at Ace Hardware or Home Depot

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Hello @KevinGaus ! On page 2 of this thread, in this post, I found my (I think they were 1/2") u-bolts from TNJ Murray (P/N: 11609677) but the link is now dead.

Searching TNJ Murry for "u-bolt" it appears they have u-bolts for the LWS gun ring system, but I'm not sure of the outside diameter of those "legs" so I'm not sure if they'd fit an M66 or the holes in the back of your cab:
https://tnjmurray.com/12450097u-bolt-weapons-kit-m923.html?fireglass_rsn=true

My M66 gun ring legs are 2.25" in diameter, and the whole setup weighs somewhere around 600 lbs. Since you'd be using at minimum 4 u-bolts, I would think you could use virtually any 1/2" U-bolt of sufficient length with a ~2-1/2" inside radius. The back of the cab isn't very thick anyway.

You could also contact:
https://www.bmgparts.com/
if you want to find more hard to find parts, or more "historically accurate". When I talked to the fellow there, according to him, the older M-49 gun ring's u-bolts were a flat strap on the back, curved portion to better grip the gun-ring leg. Obviously premium/desirable parts there.

Valence said:

Hello @KevinGaus ! On page 2 of this thread, in this post, I found my (I think they were 1/2") u-bolts from TNJ Murray (P/N: 11609677) but the link is now dead.

Searching TNJ Murry for "u-bolt" it appears they have u-bolts for the LWS gun ring system, but I'm not sure of the outside diameter of those "legs" so I'm not sure if they'd fit an M66 or the holes in the back of your cab:
https://tnjmurray.com/12450097u-bolt-weapons-kit-m923.html?fireglass_rsn=true

My M66 gun ring legs are 2.25" in diameter, and the whole setup weighs somewhere around 600 lbs. Since you'd be using at minimum 4 u-bolts, I would think you could use virtually any 1/2" U-bolt of sufficient length with a ~2-1/2" inside radius. The back of the cab isn't very thick anyway.

You could also contact:
https://www.bmgparts.com/
if you want to find more hard to find parts, or more "historically accurate". When I talked to the fellow there, according to him, the older M-49 gun ring's u-bolts were a flat strap on the back, curved portion to better grip the gun-ring leg. Obviously premium/desirable parts there.

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Thank You. That’s the best price so far. But I was hopeful I could find the early U-bolts. Like these.
The flattened curve will have more surface area and better clamping ability.

Valence said:

You could also contact:
https://www.bmgparts.com/

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If there ever was a "specialty" store in this world, well then that BMGparts store would be the ONE.

What a hoot!

Just found this thread when looking up some information on the M66. I mounted one on my M1078 for my 1919A4.

Admittedly, I didn't read every word but did read a lot and you did a great job! Learned a few things as well.

I didn't realize there was a cap for the pintle hole. My ring didn't come with one. May need to try and locate one just to help keep the dust out. Also, didn't realize there is a barrel clamp for the 1919 to keep is secure. Your note on the rust... I am not 100% impressed with BMG Parts either. I'm happy they have stuff no one else does, but I think it's all really spendy and comes up a bit short. It is what it is. He did honor a price mistake on his site for me though so I appreciate that. I ended up getting the 1919 cradle from them and modifying it so the gun would be secure and not flop around while driving. My rings hand brake could use a little tightening though & that's the information I was looking for. Not sure if it can be.

Thank you for the great documentation!