There are three rounds in the photo of caliber .90 variations. The left is the more typical Practice loading with the T4 case. The headstamp is CAL. .90 T4 4430 F.A.IW.PB. The base is over stamped in ink:AMM LOT E-1130 3P A and there is a black band across the base. These are typical markings for this round and the common case type. The center round is a pressure test loading with the T3 case. The headstamp is CAL. .90 T3 2536 F.A. IE.D.B. The T3 differs from the T4 in that the T3 has a very large primer hole (16mm) versus 10mm in the T4. The right hand one is what I have the question on. It is also a pressure test loading, but it is in a very unusual rebated rim T2 case. The headstamp it CAL. .90 T2 1075-F.A.IE.DB. I have virtually no "official" information on the cal. .90 series and in particular the T2 case type. Anyone by chance have something?
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Cal. .90 Case Help
- Thread starter EODGUY
- Start date
.9" t1, t2, t3, t4
Very nice rounds there, anything other than the T4 are very very hard to find.
The only information I have on these rounds is in the book Military Cartridges part 4 by W.D. de Hek, page D166 which reads as follows:
"The .90" (23mm) automatic cannon for this cartridge was developed for useas aircraft armament; the Ordnance Department of the United States Army started its development around 1935.
The T1 was a heavy weapon with a maximun firing rate of 150 r/min; the cartridge as a matter of fact was better than the weapon, and the development was continued.
The T2 was supposed to be an improved Oerlikon design, but because of its inertia lock the weight was rather too high. An additional disadvantage was that, in order to produce the maximun rate of about 400 r/min, without jamming, the cartridge cases had to be lubricated.
The T3 had a different breech lock from the T2, its firing rate however remained the same.
The last weapon in this caliber, the T4 was designed by Colt factories, it was a serious competitor for the 37mm Browning aircraft cannon. It was however never officialy adopted and after 1945 it soon became obsolete.
The case is based on the 28 x 199/SR (1.1"). It always consists of brass, with and impressed and ringed primer head. On the side of th case the powder data and the initial velocity are mentioned.
Further information is contined in Chinn 1- 607/609, Chinn III- 30"
Hope this helps and if by chance you have a spare T2 or T3 I'd be interested.:tinysmile_shy_t:
Dave.
Very nice rounds there, anything other than the T4 are very very hard to find.
The only information I have on these rounds is in the book Military Cartridges part 4 by W.D. de Hek, page D166 which reads as follows:
"The .90" (23mm) automatic cannon for this cartridge was developed for useas aircraft armament; the Ordnance Department of the United States Army started its development around 1935.
The T1 was a heavy weapon with a maximun firing rate of 150 r/min; the cartridge as a matter of fact was better than the weapon, and the development was continued.
The T2 was supposed to be an improved Oerlikon design, but because of its inertia lock the weight was rather too high. An additional disadvantage was that, in order to produce the maximun rate of about 400 r/min, without jamming, the cartridge cases had to be lubricated.
The T3 had a different breech lock from the T2, its firing rate however remained the same.
The last weapon in this caliber, the T4 was designed by Colt factories, it was a serious competitor for the 37mm Browning aircraft cannon. It was however never officialy adopted and after 1945 it soon became obsolete.
The case is based on the 28 x 199/SR (1.1"). It always consists of brass, with and impressed and ringed primer head. On the side of th case the powder data and the initial velocity are mentioned.
Further information is contined in Chinn 1- 607/609, Chinn III- 30"
Hope this helps and if by chance you have a spare T2 or T3 I'd be interested.:tinysmile_shy_t:
Dave.
Tony Williams
Well-Known Member
Yep, there was a series of four guns all different and using three types of ammo with different cases. The text quoted is a bit ambiguous, only one of the used a necked-down 1.1" case, the others were much smaller.
Somewhere I have a postwar summary of the gun series...
Somewhere I have a postwar summary of the gun series...
Nice to see another T2. All I get when I ask about them is blank stares. Did hear about the guy who found a case of the T4s, which should account for their availablity (and why you can find them in theircardboard shipping tubes occasionaly). Chinn and Saunders supplied all else I know. The headstamp is the same as listed above except instead of an 8 there is the ordnance wheel. The case has a staked primer, which is struck, and it appears as though the case has been cycled as it has 2 extractor dents on top of the rim. The projectile has black over painted on top of yellow with INERT in white on top of that. The shell body is marked; CAL.90.T I,E.D.B._upside down flaming bomb LOT 575- The fuze is a dummy and unmarked.
Attachments
Tony Williams
Well-Known Member
Can one of you lucky gents with a T2 please provide me with the basic case measurements: case length, rim diameter and maximum body diameter?
For case length I get 140mm, rim diameter 24mm, maxium body diameter at base 29mm, case diameter at shoulder 29mm. Measurments rounded down to nearest mm. Accurate to within 2 - 3 CH. Your results may.
Tony Williams
Well-Known Member
Many thanks! :beer:
No. Thankyou for all the information you provide at your website. Usualy the first place I go after a new aquisition. Right after I check your books. If you need a 90cal. T-4 I see them about and will probably be crossing paths with a dealer who has one in the 40-50$ range.
Tony Williams
Well-Known Member
Thanks! I have a T4 (they're fairly easy to come by even on this side of the Pond), but I'd like measurements for the T1 round (well, actually I'd like examples of the T1 and T2 rounds for my collection, but I suspect that even if any became available they'd be outside my price range...)