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 Author  Topic: 40mm ammo load out
David Waples

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of David Waples  Posted on: Feb 9, 2014 - 2:15pm
Hi all,
Does anyone have information on the preferred loud out of 40mm ammo the crews used? I know from reading Al Ross' book that ammo type used was HE, AP, and T. But was there a preferred mix of ammo?
Thanks
Dave

David Waples

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  Jerry Gilmartin

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Jerry Gilmartin   Send Email To Jerry Gilmartin Posted on: Feb 9, 2014 - 3:54pm
Hi David,
I looked in the Tactical Orders and Doctrine book and in the Instruction booklet called "Know your PT Boat". While it is talking about the 37mm cannon, it may be similar. Also, I bet it depends on when and where they were. If they were a PT Boat stationed off Okinawa, I would imagine they would have a loadout more suited exclusively for AA (anti kamikaze) and have no AP rounds at all. I would guess the most common load out would be all HE-T-SD (High Explosive-Tracer Self Destroying) which would be Light green body with a White stripe and Red nose.

"37mm gun
(omitted numbers 1-15)
16. Both AP and HE have tracer. Good results have been had with a ratio of 1 AP and 3 HE.

40-mm Gun.-This gun is best operated with 4 men but 3 men can do a good job. It is a wonderful gun for both AA and surface fire. It seldom jams. The prime point to remember is load the shells at the proper angle- nose canted downward. "

Of course, like Jack says, they never went by the book at the war zone, if they could even find a book or a Tech Manual, they just did what they could do with what was available.
Jerry

USS Alaska 40mm ammo magazine notice HE-T-SD loads


PT boat with visible HE-T-SD in loader assembly


40mm ammo color decoder board



Jerry Gilmartin
PT658 Crewman
Portland OR

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David Waples

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of David Waples  Posted on: Feb 9, 2014 - 4:09pm
Thank you Jerry,
I posted your information on the modelwarships.com board. I'm sure it will be helpful to the modeler.
Much appreciated!
Dave

David Waples

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David Waples

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of David Waples  Posted on: Feb 11, 2014 - 8:47pm
Jerry Beasley asked me to post this information on the modelwarships.com board and I thought I would go ahead and post it here as well..


Great questions and some good follow up on tracers and the make up of individual clips. While I'm a PT modeler I also got bit by the ammo bug and have been a serious collector of .30 cal, .45 cal, .50 cal, 20mm, 37 mm and 40mm ammo for the past 10 years or so. It started as all the ammo carried on a PT boat but my wife drew the line at depth charges and torpedoes - I am however always on the lookout for a 5" rocket if anyone (hint: Jerry G) knows where one might ever be available. I'm also involved with restoration of military aircraft which carries over in to the full restoration on the ammo.

I have never posted a photo on the forum so Dave Waples has agreed to post them for me.

In my experience I have never seen a mixed clip of 40mm ammo used in an operational weapon, whether used in ground vehicles such as the M-41 Duster, shipboard usage or airborne platforms such as the Specter gun ships. As reference each of the ammo boxes or cans that I have in my collection or referenced in photo sources have the ammo type and nomenclature marked on the outside of the container and in my experience are limited to a single ammo type.

First I included a chart of the 40mm rounds used in WWII by the US Navy - this was put together by a close friend and fellow collector and he gave me permission to publish in the forum and for it to be used by any of the forum members in you would like - I am going to do a new one that will show all the proper nomenclature that should be painted on each projectile - the type of round is on one side and the lot information is stenciled on the opposite side.

As to Murphy's Laws of Combat that "tracers work both ways" - very true, but you will see reference to a "dark" or "dim" tracer as well as a delayed ignition tracer. While a lot has been written I think in the end they are really all the same animal. The problem especially with large caliber tracers is that when they ignite as fired they can destroy the gun crews night vision, and they draw a straight line from the target right back to the barrel of the gun. The dark or delayed ignition tracer has a very slow burning ignition train that allows the projectile to travel several hundred yards from the barrel before igniting the tracer element. The crew maintains their night vision and the individuals on the receiving of the incoming rounds can only guess at where the shooters are located.


As to the sequencing in the 37mm cannon, I suppose a lot would depend on the individual target type being engaged. There are a number of good pictures of sequencing in the airborne version of the 37mm, but I was able to find one good photo from what appears to be an operational WWII PT boat. It is in black and white but with the color differentiation as well as the cartridge length it is clearly sequenced HE/AP/AP/AP/HE/AP/AP/AP.

40mm USN identification chart


37mm load out


David Waples

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TED WALTHER

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of TED WALTHER   Send Email To TED WALTHER Posted on: Feb 12, 2014 - 6:38am
Dave;
I know several years ago, we had a Army Navy(its been open that I know of since at least the 1970's) store around here and they had what looked like 2 F-86 Sabre drop tanks out front, they also had 2-3 blue(practice) 5 inch rockets!
I went back a few weeks ago looking for a N-1 Deck Jacket(but they only had smalls), but they only had 3. anyway I did not think to look for the rockets this time, but when I go back I will look for you.
Take care,
TED


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Randy McConnell

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Randy McConnell  Posted on: Feb 12, 2014 - 7:49pm
The image of the 37 mm gunner that Dave posted for Jerry is from my dad's collection. Here's a better version I printed from the original negative around 1965. I reprinted quite a few of his pictures at that time, the printing quality was a little better in a dark room versus the cabin of a PT! The negative has since degraded to the point of being unusable. This doesn't really add much to the discussion but might make the different types of 37 mm rounds more evident.

The gunner in the picture is Dusty O'Neil, Radioman on PT361. Posing at the 37 mm was fairly popular but this is the only picture in my dad's collection with the gunner wearing a vest and helmet, and a full magazine.

I do remember Dad saying that they would load the 50 cal belts with a higher ratio of tracers for the psychological effect. I don't recall anything about the 37 mm and 40 mm.

Randy McC






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Randy McConnell

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Randy McConnell  Posted on: Feb 12, 2014 - 7:54pm
I just noticed that printing is visible on the heads of some of the rounds in the 37 mm magazine. Unfortunately they aren't quite legible when I blow up the original scan.

Randy McC


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David Waples

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of David Waples  Posted on: Feb 13, 2014 - 4:33am
Thanks for the history of the photo and posting it for us. It must have been quite an experience to fire that gun.
Dave

David Waples

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PRJM3

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of PRJM3   Send Email To PRJM3 Posted on: Feb 13, 2014 - 7:19am
Dave,

That was exactly my thought when I was examining the picture last night!

Randy McC

Randy McConnell (Randall J. McConnell III)

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TobyKnight

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Post a Reply To This Topic    Reply With Quotes     Edit Message   Posted on: Mar 25, 2014 - 2:25am
Hi,

Can anyone assist me with a query regarding loose ammo. I've just bought the AFV Club 40mm ammo set in order to add the extra clips to my Bofors, but also to the ready ammo locker behind it. In extended combat would there ever be boxes of ammo on the deck from which the clips would be removed from when the ready to use ammo was exhausted, or would boxed ammo not be placed on the deck at all??

Thanks

Toby


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