105mm M27 recoilless ammunition

I have a 105mm marked HEAT round and case for the M27, I was wondering how uncommon are these? I know the 106mm rounds for the M40 rifle are out there but the 105mm rounds were only made for a few years before it was replaced by the 105/106mm M40 series rifle, those later rounds are different and marked 106mm to avoid confusion.

You got images for us?

Sure not very common as you say.

I have photos but I’m trying to figure out how to post it here.

Hello KaptainsSurplus, assuming you already have images saved to your computer use the following method to post photos. First, open the folder on your computer with the image you wish to post. Start a new reply to your post. Then hover the mouse pointer over the photo file you wish to upload and hold down the left mouse button. Then drag the file from the folder into the reply window. It should automatically upload a copy of the image from your computer to the reply. Hopefully this makes sense.


Thanks guys for the replies and how to upload. Once I get back in town I’ll upload some pics for you guys.

Here is my 105mm Recoilless case.
Load was the HEP-T M326 which was a bit secret and an early HESH ??
Dated 1952. White letters are a bit worn but still an example.

Who is the case maker EPO ?


Ron, if I remember correctly HESH is the British naming while HEP is the US designation.

EPO = Economy Products Co

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Thanks for that info EOD.

Alex and Ron, “EPO” was not assigned to Economy Products Co. until 1986. The correct identification of this “EPO” is Ekco Products Co., Massillon, Ohio. This is the same company previously known as Edward Katzinger Co., who had its main factory at Chicago, Illinois and used the “E. K.” headstamp.



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Fede, great info!
I can not find this info in the US code list. Could you tell where this ID is sourced from?

It is identified in the manufacturers list of 1953 and also in data cards from other cartridges.

Good to know, thanks!!!

Finally was able to get a photo. The 105mm is on the left and 106mm on the right.

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Thanks! Does the 105mm have a headstamp or paint markings on the case head?

Well check tonight for you.

So this is a “rare” beast indeed.

Case reads: 105mm T6 Lot-A-1-2.

Projectile reads: XX 457 F78RCO 52 105MM T119 LOT NO 1.

Now where the 2 x are there are numbers under them maybe a 9 or 7 then a 3.


Thanks for the images!

I do not remember the 105mm being smoothbore and the T-numbers are also hinting this one to be “more expereimental” than the “regular” 105mm which is scare already.

Anybody with more insight?

The HEAT rounds didn’t have a pre-rifled rotating band, all the others do.