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2in Mortar
- Thread starter Andysarmoury
- Start date
I have found some info that expands a little on what has already been given, as follows:
DWS notes on ammunition, issue No 15, section 2, two inch mortar bombs (no issue date but printed 9/1943), Appendix 1 reads as follows:
`Sorting of mortar bomb tails and conversion of aluminium tails
ACI 862/41 (extract).
1. As a result of investigation it has been established that 2-inch mortar bombs fitted with aluminium-silicon tails are liable to fall short due to the fracture of the tail unit on firing. Bombs fitted with Mazak are not liable to fracture.
2. Bombs 2-inch mortar will therefore be sorted out by types of tail. The following information will facilitate identification of the two types of tail unit:
(a) All bombs filled before September, 1940, are of the aluminium alloy type.
(b) Bombs fitted with zinc alloy (Mazak) tails are marked with a `Z' stamped on one fin. In addition, a streak or blob of red paint should be found on one fin of the Mazak tail. It is possible that a few lots have been received without the red marking on the tail. Identification in each case will therefore be made by the `Z' stamp.
3. Bombs fitted with aluminium alloy tails are, or should be, fitted with a 47 grain cartridge. The lettering on the body of cartridges of this type is BLACK. Bombs fitted with Mazak tails are, or should be, fitted with 55 grain ballistite cartridges. The lettering on the body of this type of cartridge is RED.
4. Care will be taken, during the sorting, as in para 2 above, that no 55 grain cartridges are associated with aluminium tails, and similarly that no 47 grain cartridges are associated with bombs fitted with Mazak tails.'
End of ACI 862/41 (extract)
'ACI 1840/1941 (extract)
1. The sorting of tails as laid down by ACI 862/41 will be carried out for both HE and Smoke bombs.
2. Conversion of aluminium tails to prevent fractures - The conversion applies only to bombs assembled with Mk 1 cartridges. It has been found that liability to fracture of aluminium tails can be prevented by drilling a fourth tier of holes in the bomb tail. Mazak tails will not be converted.
3. Marking - When aluminium tails have been converted, the packages will be identified by the letters `HC' stencilled in 2-inch letters on the package.'
(End of ACI 1840/1941 extract)
'Specification for the method of conversion was for a fourth tier of holes to be drilled above the existing three tiers at the bomb end: the holes to be 0.2 inch diameter and 0.4 inch centre to centre from the third tier; cartridges to be removed before drilling and inside of the hole to be cleaned after drilling.'
Page 3 of the above DWS notes states `The production of bombs with steel tails is to be expected.' While page 8 mentions that the Mazak tail was liable to fracture at extreme low temperature `and is being replaced by bombs with steel tails'.
DWS notes on ammunition, issue No 15, section 2, two inch mortar bombs (no issue date but printed 9/1943), Appendix 1 reads as follows:
`Sorting of mortar bomb tails and conversion of aluminium tails
ACI 862/41 (extract).
1. As a result of investigation it has been established that 2-inch mortar bombs fitted with aluminium-silicon tails are liable to fall short due to the fracture of the tail unit on firing. Bombs fitted with Mazak are not liable to fracture.
2. Bombs 2-inch mortar will therefore be sorted out by types of tail. The following information will facilitate identification of the two types of tail unit:
(a) All bombs filled before September, 1940, are of the aluminium alloy type.
(b) Bombs fitted with zinc alloy (Mazak) tails are marked with a `Z' stamped on one fin. In addition, a streak or blob of red paint should be found on one fin of the Mazak tail. It is possible that a few lots have been received without the red marking on the tail. Identification in each case will therefore be made by the `Z' stamp.
3. Bombs fitted with aluminium alloy tails are, or should be, fitted with a 47 grain cartridge. The lettering on the body of cartridges of this type is BLACK. Bombs fitted with Mazak tails are, or should be, fitted with 55 grain ballistite cartridges. The lettering on the body of this type of cartridge is RED.
4. Care will be taken, during the sorting, as in para 2 above, that no 55 grain cartridges are associated with aluminium tails, and similarly that no 47 grain cartridges are associated with bombs fitted with Mazak tails.'
End of ACI 862/41 (extract)
'ACI 1840/1941 (extract)
1. The sorting of tails as laid down by ACI 862/41 will be carried out for both HE and Smoke bombs.
2. Conversion of aluminium tails to prevent fractures - The conversion applies only to bombs assembled with Mk 1 cartridges. It has been found that liability to fracture of aluminium tails can be prevented by drilling a fourth tier of holes in the bomb tail. Mazak tails will not be converted.
3. Marking - When aluminium tails have been converted, the packages will be identified by the letters `HC' stencilled in 2-inch letters on the package.'
(End of ACI 1840/1941 extract)
'Specification for the method of conversion was for a fourth tier of holes to be drilled above the existing three tiers at the bomb end: the holes to be 0.2 inch diameter and 0.4 inch centre to centre from the third tier; cartridges to be removed before drilling and inside of the hole to be cleaned after drilling.'
Page 3 of the above DWS notes states `The production of bombs with steel tails is to be expected.' While page 8 mentions that the Mazak tail was liable to fracture at extreme low temperature `and is being replaced by bombs with steel tails'.
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All these DWS notes can be found at the National Archives in Kew London, A wealth of info there, thats where i found all my two inch mortar info as well as enemy ordnance as well. Worth the train fare up there.
pointblank0
BOCN Supporter
That really is a nice one!
I got on the TNA website yesterday after seeing BMG50's info but try as I might could find no reference to DWS Notes on Ammunition when searching - how best to track it down? There was lots of info about 20 mm and higher calibres used in aircraft, mostly for evaluation purposes.