Different calibers and models for weapons

Hello all! I’d be nice to begin with a few sentences in order to express my admiration for all of you who keep this site&forum alive. But unfortunately I do not have too much time so… I will end the introduction here, hoping that you’ll understand what I was trying to say.

I think a discussion about the problem raised by the different models and calibers of the cannons used by the Romanian artillery (including naval, coastal and AA) and individual weapons could be illuminating for some aspects concerning the logistics and even the battle effectiveness of the Romanian army in WW2. More specific:

Were the guns of different caliber or model use by the same unit (e.g. the same artillery regiment or even battalion), or they were distributed to different units according to the model and caliber. To be even more specific, the Romanian field artillery units used Schneider model 1897, Krupp models 1904, 1912, 1917, Skoda model 1928 and Schneider-Putilov model 1936 75 mm cannons (not to mention some Soviet captured guns, 76 mm). Each of these had most probably different specifications and operating procedures, different specific field manuals. How were the artillery soldiers trained then? Did they know how to use a specific model and became (more or les) unable to operate a cannon (a different model) if transferred to another unit?

One of the most illustrative cases is that of the Romania AA artillery (then called ACA - “Apararea Contra Aeronavelor” - Anti-Aircraft Defense). It used (besides the Hotchkiss 13 mm AA machine-gun) a large variety of guns of different models and calibers: Oerlikon 20 mm, Gustloff 20 mm, Rheinmetall 37 mm, Bofors 40 mm, Vikers-Resita 75 mm, Skoda 76,6 mm, Krupp 88 mm. How were guns this distributed to different AA units, and how was the different caliber ammo supplied to them (a logistical nightmare I’d say…). How was the situation (in comparative analysis) in other contemporary armies (both axis and allied, both major and minor powers)? What specific combination of factors lead to such a low level of calibers&models standardization? Why were there so many types of weapons?
If I am not mistaking, a somewhat similar situation existed in the Finish army during the 1939-40 Winter War; but what could be accepted as a workable (tough not at all desirable) situation for a small size, half territorial army could be a real reason for lack of effectiveness defeat and failure for a rather large one as were the Romanian Armed Forces in WW2 .

And a final question (from me, for now:)) in this topic. How could be a captured weapon be used if the army to wich belong the one who got it uses a different caliber ammunition (e. g. the Soviet model 1928 light MG or the Musin-Nagant rifle, the last one allegedly used as standard sniper-rifle by the Romanians)?? I remind you that both these weapons used the 1,62 mm ammo… or did they only get along with captured ammo depots?

Hello and welcome to the forum.

I don't know the exact type of guns per artillery regiment, but at the beginning of war the level of standardization was not so low. We can say that most of the pieces in the field guns battalions of artillery regiments were recalibred Schneider-Putilovs, for example, while the independent artillery battalions had a majority of Schneider 105mm long guns and 150mm Skoda howitzers. The problems appeared during the war, when due to the losses in material, the pieces had to be replaced with older or captured pieces. I have seen some of the training handbooks for the artillery pieces acquired by Romania, and I can say that for someone already experienced in the operation of a quick firing gun ("piesa cu tragere rapida"), he could learn the operation of the new gun within a day. This is my opinion now, of course I may be wrong, given the case. As for the guns captured from the Soviets, they used the captured ammunition, or delivered by the Soviets after August 1944. However the captured weapons wer obviously not preponderant.

The after-action reports of Odessa showed that artillery units had enough ammunition, but the way the firing was conducted led to a waste of ammunition without achieving the desired effect. Therefor it was not a cause of caliber standardization, but doctrine.

Thanks Dragos.
And by the way, impressive story about you grandfather and the officers scholl near Arad... Were they the well-kown "heroes from Paulesti" ("eroii de la Paulesti)?
However, there's got to be some side efffects of having so many models and calbers for the weapons. Othervise I don't see why the US (who were I'd say the undisputed champions in logistics matters, during WW II) were so focused in having the same model and caliber for each type of weapon, from howitzers and AA MG to the officer's side-arms...
How could the magnitude of these "side-effects" be measured?