juzz,
To expand on what lynx has posted, the Soviet State was pretty much hard-nosed when it came to passing weapons-trials. A designer that made good, reliable weaponry that met the specifications of the state was generally going to go places. A designer that wasted too much of the state's time with cheap, poor weaponry could very well wind up in Siberia - chopping wood and carrying water. Hence, Soviet weaponry was quite reliable on the whole. If it was not completely reliable, but was of promising design, the designer would be given the chance to rectify the shortcomings before closing down the project.
lynx,
The La-7 was built out of 3 factories from Gorkii, Ulan-Ude, and Moscow. It wasn't until January 1945 that the three cannon version of the La-7(150 rounds for each cannon) went into production. Up until that time only the two cannon versions(200 rounds for each cannon) were produced.
Sorrow,
I once bagged a B-17 from over 30k while in a La-5, but it was a bit of work and luck combined. Usually our squad flies around 20k. What's nice is that if we have to go to the deck, our la-5 will only get better.
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129 IAP VVS RKKA