I need a H&K USP9 for backpacking and range reasons. I have seen a compact and full size version of it. Should I go full size or compact. I need the one that is more accurate and the one that is the most reliable. You never know when youor life will depend on your weapon in the wilderness.
Both are as reliable as the other one. BUt, if size is not the issue, get the fullsize.
I used to have a fullsize 9mm USP, but the grip was rather big for me. I needed money for another gun purchase, so I sold it. I do have a USPc, though. And, the grip circumference is smaller on the compact. So, it fits my hands better.
But, while the grip is almost fullsize in length. the barrel is still a compact. I shoot it well, but not as well as I did the fullsize - especially at further distances.
Reliability: Both are basically the same design internally and externally. The buffer assembly is slightly differnt but both will provide the same level of reliability.
Accuracy: About the same again. A great deal of that has to do with the shooter and how well the particular gun fits thier hand.
Here's a thought... You mention it's for wilderness carry and that "life may depend on it." ok, the USP40 is the exact same size yet the cartridge offers a bit more oomph than the 9mm. There are occasions the 9mm would be more than adequate but there's some where more is definately better. If more is available in the same size pkg, having the same design (reliability) and accuracy (if the shooter does thier part) why not go that route?