Need Some Help With New 76mm or 3" Projectile

[pzjgr]

Need some help with a new projectile I picked up....I am at work and will have to post pics later, but hopefully from the description someone may be able to start pointing me in the rigt direction...

Its a bit of an oddity to me...it seems to be an HE or Shrapnel 3" projectile for the M1902/M1903 Seacoast guns (the ones which use the long 3" case) but is marked (looks very original to me) "76 G" (thats it, no other nomenclature except a weight zone "+" above the 76 G). It is OD paint with yellow stencilled markings (not rolled like a factory job). It does not currently have a fuze...

Nitty Gritty's...Overall length of projectile is 11.5" (292.1mm)...BUT it has an adapter screwed into it which is stamped " 3"AA Adapter, MK-I SWACO" so that is the length with the adapter...the projectile itself is 10.81" (274.6mm). Tha adapter is about 5/8" (15.9mm) in height. It has an early narrow single driving band, a little over 1/2" wide...

It looks similiar to the 2nd to last projectile in the third pic in this thread... http://www.bocn.co.uk/vbforum/threads/75869-3-inch-projectiles

I know its tough to say without pics but I wanted to get this thread started...

So questions for now...

1) Exactly what projectile is this.

2) If its an earlier 3" projectile based on driving band, were the re-used/re-loaded for use in the 76mm gun?

3) What is the " 3"AA Adapter, MK-I " and what type of fuze would b used on it (it appears that if the adapter is removed the standard large US type fuzes would work...ie, I have a spare M564 MTSQ sittng on my desk, it won't screw into the adapter, but if I could unscrew the adapter, it looks like it would mate up proper...)

As I said, I will post pics tonight....

TIA,

Mike

 

[HAZORD]

Mike,

The projectile in the photo you reference is a high velocity shrapnel for the old 3 inch AAA guns. The older projectiles were not used in the newer guns, because the rifling twist was changed, and they went to the larger rotating band. They rebarreled the guns to the newer rifling, and no longer fired the older projectiles. The older style was left over from WWI, and they used the older models to train the troops in WWII.

The M564 fuze you reference has a 2 inch thread diameter. The other common size for larger projectiles is the 1.4 inch diameter, which is what all of the older WWII and WWI MT fuzes were manufactured with.

Your projectile sounds like a Mk. 1 HE, if it has the adapter in the nose.

It is always a lot easier when you post a photo.

 

[pzjgr]

Thanks, that is what I kind of thought....here are the pics....

You can see the (I believe) screw in adapter, along with the stampings (tough to see but they are there)...

As I said, the paint looks pretty original, or if anything pretty old!

Narrow driving band, non-boat-tail base...

 

[HAZORD]

Yeah, it appears to be the Mk. 1 HE, which was used in the really long case , and the shorter model too. You need an older fuze for it.

The lettering isn't original because it was done with a stencil instead of a rubber lettering block. Also, proper color code was yellow body with black lettering, so wrong on all color and marking. Thats a good projo, and hard to find.

 

[pzjgr]

Ok, makes sense, the stencilling threw me since it appeared so old....so I think the game plan will be to wire brush it down to bare metal, and re-paint.

I have the FM for the 3" Seacoast guns which covers the ammo...and luckily, I do have a long case 3"...it currently has a 3" M79 AP shot in it, as a placeholder, didn't think I'd ever find a proper projectile for it...

What fuze(s) should I be looking for to complete it? If I removed the adapter would the WWII M48 PD fuze fit? Or I am better off leaving the adapter in, and finding an older fuze?

 

[HAZORD]

OK, first of all, use the adaptor on the nose and get a proper fuze. One proper fuze is the one on the 5th projo in photo number one of Randall's photos that you referenced above (MK II fuze).

There are 4 lengths of 3 inch antiaircraft cases in two groups. Call the groups tall and short. Each group has a taller case, and those are the ones that are for the old style 1/2 inch rotating band like your MK 1 HE projo has. The tallest case of the tall group is the MK 1 and the MK 1A1 at 27.15 inches long, and the tallest of the shorter group is Mk II and Mk IIA at 23.65 inches long. The shorter case in the shorter group is for your M79 projectile (MKII M2 case), as it was used in the M10 tank destroyer. It will also work in the M26/M26B1 Super Sherman case.

The shorter cases in each of the groups are for the newer projectiles with larger rotating bands, so short case with big band equals same length chamber as long case with small band. Thats why they have 4 lengths, to keep the same distance from base to top of rotaing band (chamber length)

Posts about case lengths:

http://www.bocn.co.uk/vbforum/threads/38079-3IN-Case-ID?highlight=antiaircraft

http://www.bocn.co.uk/vbforum/threads/80506-Would-this-be-a-75mm-or-76mm?highlight=seacoast

 

[pzjgr]

Yeah, I checked my 3" case, it is headstamped "3IN MARK I, GUN MOD OF 1903-17" and is approx 27 1/8" long, so that will be perfect for the new projo once its stripped and repainted....I may be able to find a fuze at my buddies place where I got the projectile, he had several of those old style fuzes laying around the garage, I'll go back and see if I can find the right one....

Like I said, I just stuck the M79 projectile in for the time being...I didn't think I'd ever find a correct projectile for it...now I have to find another proper 3" case for the M79 projectile...I have a navy 3" 50cal, but that has the original Navy APCBC projectile in it...

It was a good day at my buddies place (he is a full time militaria dealer, and his house and three bay garage is full of stuff!) about 5 minutes of digging I found the 3" projectile, a WWII M41 frag container, and a 57mm round with the AP shot projectile (will look good next to my 57mm APCBC round)...he wanted the princely sum of $100 for all three. Needless to say, I took 'em all!

 

[Lou]

If by chance anothe fuze pops up?..

 

[pzjgr]

Yep, looks familiar! If I find 2....I'll let you know!

 

[Lou]

It would be much appreciated! If your looking for something in particular for trade,let me know.....
Now if I can shake Johns tree for the propper case:tinysmile_hmm_t:..........I do have that poor lonely rocket Wrhd,,,,,,

 

[shelldude]

Hello Mike, John & Lou,

Sorry to get in on the discussion late. To the best of my knowledge, these are the four fuzes that would go correctly with the 3-inch Mk. I HE projectile with adapter. I apologize for the quality of the photographs, it is getting late!
They are L to R: 1918 Waltham MK. I M/T fuze, 21sec. AA MK. III combustion time fuze, 1918 23 sec. AAF Mark II Type "S" combustion time fuze with "pagoda" style tip and 1918 20 sec. AAF Mark II Type "S" combustion time fuze with "pointed" tip.

Best regards,

Randall

l

 

[HAZORD]

Randall, good to see you are alive! Nice fuzes!

 

[pzjgr]

Randall, that is fantastic stuff, exactly the info I was looking for, thanks much....I'll post new pics, once I get the shell stripped and repainted, hopefully find a fuze, and get everything mated....

 

[pzjgr]

OK, so this weekend I stripped and wire brushed the shell clean...and interestingly enough, under the paint the projo and adapter were stamped pretty much exactly like Lou's...

I painted it yellow, the stencilled it. I took a bit of an educated SWAG on the proper stencilling, but it looks convincing to me, and really, 99.9% of anyone who would see it would have NO clue...If any one has the exact stencilling let me know, I can change it.

I am taking to cheating...no more under coat, letters, overcoat, peel. These are just stuck on direct...very sharp, and no bleed throughs, no scrapes, no pulls....and you wouldn't know unless you got right up on it...

Another interesting tidbit, might help you out Lou, at least until you can find a proper fuze....the Navy Mk 22 fuze fits it perfect...I borrowed the one on my wooden training round on a hunch...looks good...and the Mk 22 are fairly easy to find.

I am hoping to go to my Buddies house in the next couple of weeks to see what I find fuze wise....

 

[HAZORD]

The paint job looks very nice. If you do plan to reletter it, you can leave off the "with tracer", cuz it doesn't have one.

Some 37mm stuff from WWI had tracers, and there is the odd extremely rare 3 inch projo that has one, but the Mk. I HE doesn't. The first large caliber U.S. rounds that had tracers were the 90mm ones from late WWII, and typically the tracer rounds are tank and antitank projectiles. Your projectile is AAA or seacoast gun, and the seacoast application has more penetrative semi-armor piercing projos for those types of targets.

 

[shelldude]

Hello Mike,

Your restoration paint job on the Mk. I HE looks great. Good luck on the fuze hunt. John's eagle eye for detail is spot on. I looked at your photograph and didn't think twice regarding the tracer.

Best regards,

Randall

 

[pzjgr]

I can get rid off "WITH TRACER" easy enough, thanks for the tip....

Do you know what the deal with the base is? It has a weird very thin almost foil like covering on it...I just assumed it was a tracer compound under it....

 

[HAZORD]

Back in the WWI to WWII times, the U.S. used a copper/brass plate on the bottoms of their HE projectiles, as an insurance policy, to keep the projectile from detonating in the bore of the gun in case there were any imperfections in the forging where flame from the burning propellant could slip into the explosive cavity. Later HE projectiles have a thin steel plate welded over the base of the projectile. The copper plates are caulked or crimped in place over the base of the projectile. This was even done with explosive projectiles that had base fuzes. The plate covers the fuze.

This practice added cost, so it wasn't done with the other types of projectiles like chemical, etc.

 

[pzjgr]

Again, thanks for all the help and info guys...here are some pics of it mated up with the case I had....I stuck in the dummy Mk 22 fuze from my wooden 3" 50 cal training round temporarily...until I find what I need. I did check back at my buddies place...no dice on the fuzes...although I did pick up a very nice Navy Mk 18 Mod 2 mechanical time fuze...and a 75mm Mk I shrapnel projectile and case.

I would guess finding a Model 1907 M fuze would work on the 3" round, as from what I can tell the 21 sec AA Mk III fuze is just the Model 1907 M with the percussion element removed....

Anyway, its a heck of a long round!

 

[shelldude]

Hello Mike,

You're correct, the Mk. III appears identical to the Model 1907 M except for the inscription and lack of percussion device.

Best regards,

Randall